The Cal-look Lounge

When was the last time you saw a NEW go fast addition for the IDA that actually works?

At SCC i had the pleasure of testing out some prototype venturies for JPM.
Usually I´m around 176kmh top speed on the 1/4mile. After spending 15 minutes installing the new venturies, I had a top speed of 180,45kmh... No time for testing different jetting setups before the rain came on Sunday, so perhaps there´s even more hp to be found?

Installed one of the old 44mm venturies so you can see the difference. Pretty cool huh?

Can you post a pic only from the JPM Inlet please?
Its very interesting!

Sure, sorry for the crappy phone camera.  :)

With the JPM venturi do you no longer run the auxiliary venturi?

Spot on Matt!

Ah, that would explain the impressive flow gains. Them there aux vents restrict airflow like mofos! Good old Johannes - he's da man!

Sounds cool, they are still 44mm? also available in other sizes? Can someone explain why no auxilary vents is an improvement? What does the auxilary vent do in the first place? Trying to learn :)

That is a interesting question, and should produce a interesting reply. I mean what is a 44? is it a given depression (suction) or just a mm size.

I can see some of these babies in my future...
 

we spotted that in your carbs @scc and were wondering what mod's are done to run it like this... I saw there is a small nozzle where the outlet is? is it? very nice work, run's exellent!

Is it avaiable in 42mm too?
Can i order them at JPM? ;)

No mods are required at all to run these - Brilliant!. Yep, theres a small nozzle that lets the fuel in.

They will be available in different sizes from what I understand, Im sure 42mm. I think Johannes will try to have a few sets for sale on his Dyno Day 15th of october.

Thats a bit far away for me...I am from Switzerland.
Can everybody send them to me?

Call Johannes at +46 42 15 08 09, he can probably give you information on delivery time, sizes etc.

A timely post!
I just spoke with Johannes this past week and he mentioned the new parts he's been working on. Seems that there's just a bit more testing and fine tuning he wants to do ... always the perfectionist!

I hope he makes a LOT of them! Why would anyone NOT want such an improvement? Especially for 'all out' engines, street or strip ...  ;)
TxT

Cant wait for these hot Parts...
Have everybody more pics?
Perhaps from one without the Carb ? 8)

Johannes has asked me kindly not to put pics of the venturies themselves on the web because they are not completely finished.  ;)

Ok top secret... 8)
I can wait until the wintertests in the snow... ;) ;) ;)

could it be... jpm  cnc's a "perfect" or ideal venturi for the ida size? 

either way.. awesome awesome work and development,

though carbs are old compare to efi.. it is fresh to see more developments done to it for improvements
vs  the "we're stuck with what the bandwagon does and it works"  nothing wrong with that
but absolutely nothing wrong with moving forward with innovation too!!

good job johannes


i do hope this offer comes down to include weber 44 idf's as i recently got a pair.. :)  ;D ;D

How are they on the street? is there enough "suction" to obtain a proper progression from idle to mains when used on the street?
Or are they only to be used on race engines?

Looks clean and simple!

Starts up and runs just as easily as with the old ones. I haven't had a lot of street miles on these, but the initial impression is very good!

What tubes are you using with them?

Bruce, honestly at the SCC I can't remember because we used some that Johannes brought. F22s perhaps? Will find out.
Afterwards I installed my F2s which I have run for some years.

JS let us know of updates when the wizard johannes is done developing :)

or let him know we have people on their toes here hehe

hopefully he is also developing for IDF's


for me..

and ida's for my buddy

Yes, Its very interesting! I see the big improvement on MPH/kmh  Just wondering what was your1/4mile  E.T. Back to Back time slips?

Well, it seemed my car chose to not perform ideally on the sticky Gardermoen track. Need to work on my chassis setup.
I got at best a 1,7 60ft. ETs over the weekend was in the 12,1-12,5 range with the best ET on the last run 12,18 if memory serves me correctly.

I was ref to back to back time slips.before and after you made the changes on the prototype venturies.. Sorry, If I miss-lead you..

what holds it in place?

A name comes to my mind, annular discharge venturi.
Held in place by the same spring-clip as the regular one, I guess. No need to invent new way of doing it?

Been a little while since I've been inside an IDA, but I believe the venturi is retained by the auxiliary venturi, which is held in place by a set screw. So if there is no auxiliary venturi...

Centered by the same groove that hold the original. Zach, italian IDA´s don´t have a set screw.

My guess is that this new aux vent is the same height as the original one at it's OD, so that the stack clamps it just like stock.

Ohh, that's right. The stack holds it all in ::)

Errrr... not exactly. Now the venturie just "sits there", held by a tight fit and gravity... Doesn´t seem to go anywhere though.
I sent them back to JPM now for some o-ring machining to ensure a 100% airtight seal between the venturie and the carb body.

Also for the JPM Dyno Day 15th of october Johannes will have completed his new larger diameter "Raptor" stacks. We will flow the carbs there before and after to see the improvement.

With custom made venturis, could there be some kind of performance gain from machining the whole IDA body to a slight cone shape? Idea here to continue the cone shape of velocity stacks, not being the only "straight" part on the "port-manifold-carburator-stack" -path?

I was going to check these venturis out in SCC on saturday evening when JS told me I would be surprised, but I found myself to busy playing Black Sabbath's Paranoid horribly wrong with an out-of-tune ukulele...

wow! nice combo


as for the new JPM vents, they look really good, i hope to see some figures from the dyno day soon. has anyone also done some work on the butterflies to improve there working? i know someone who has/was going to trim the screws to have a greater and evener flow, but havent heard about that since and don't know if it would improve something?

Nicolas, I seem to remember at JPM´s flow bench, trimming the screw ends on the butterfly shaft improves the flow through the carb by 2cfm. And that it equals 5cfm at the valve.

Who would have thought?

I recall a number of years ago Deano did a small article for hotVW's that included flow bench results of profiling the throttle shafts of IDAs.  I don't remember the results.  Perhaps Deano will speak up?

Finally went to the workshop to check some time slips. It seems the best ever top speed on the car was 176,9kmh. This was actually on saturday at SCC this year. The day after I made the the 180,4kmh pass. The best pass ever on the car is a 11,95/174,95kmh. But different weekend and track.

Only old farts remember that Fredric. - I guess I´m getting old too  ::) ;D

Yes, it is actually, or at least partly a thing from the aviation world. It´s going to be really interesting to see what the difference is in flow and IRL.

T

Only old farts remember that Fredric. - I guess I´m getting old too  ::) ;D

[/quote]

Yepp, I built three seaters airplanes for SAAB / MFI in Malmö at same time I built the first VW racer.
It was 1977.
In 1978-80 we even raced at the Bulltofta racetrack. That was nice.
Something like 33 or more years ago. Now I was verrry young boy at the time so I am not old yet.....old fart maybe :-)

Gene Berg Ent. has done alot of work on profiling butterflies and throttle shafts on IDA's 1-714-998-7500

As Mark said above, Berg (Andy) RIP, made these profile butterflies and shafts. Andy made me a pair of profiled shafts and butterfly's, very nice work, very sleek. For screws he used Button Head screws, It all worked. There on my Spanish IDA's now. Contact Berg, I believe they still can do it. All worth it.

Ted

So we finally got to see a live flow test on JPM Dyno Day. The gain by switching from a "conventional" venturie to JPM´s vents and stacks was 19cfm!
The size was 42mm both on the old and new.

Some pics here: http://cal-look.no/lounge/index.php/topic,16798.0.html

Whats the price on the vents and stacks? Did he have any polished or just the black coated ones.   ???

No polished parts from JPM... The upside is that the finish is so good that polishing should not require too much work.
I believe the price is 2995 SEK for the vents and 2195 SEK for the stacks. That should include 25% Swedish VAT.

So my U.S. price would be $732 dollars, plus shipping. how much cfm increase from vents. What other bennefits from these? Very interested......
Thanks......

Call Johannes at +46 4215 08 09 or email him at info@jpmotorsport.se , I´m sure he´ll help you out.

I agree Mark Vo as the bergs do it well. My 48 ida's where done there with great results.Reasonable price too. Also try a serdi valve job while your looking to increase flow #'s. oh yeah , 88 stroke kinda helps too.  RIP Andy.. bill

if you trim one trumpet, doesn't this create an airflow difference from the other 3?  Or is it so small we don't notice it when driving?

Just like the engine lid will disrupt the flow when it covers half the inlet.

You can make over 240 HP with a bone stock IDA and a 42mm choke. Spend the money somewhere else.

Yes you can but the JPM IDA modification makes 12-14 cfm more over ALL the revs and not only at the peak.

How do you know that?  On a flow bench it is Wide Open and under no load.

It was tested and proven at the JPM dyno day. Both on the dyno and on the flow bench.

I had a broken shaft after doing this , so i like  more to get the flow from the heads  :)

Udo

How was it tested on the dyno?  first stock and then you took the carbs apart and put the vents minus aux back in and repeat?  what were the results? 

taylor, ok, where would you spend the money ( $ 400 ) than simply unbolting the carbs and getting such hp results ? yes, Good heads may net better results, but most here have good heads and you would have to tear motor down for most other improvements. Call mark  @ bergs for results/testomonies. bill

The question is about what hp you are talking about. Last week i changed conventional done 51 carbs to some that where a little bigger on the intake. 2,3  230 hp engine , no diffenece both 44 venturies . Also i had up to 275 hp with those simply done 51's on my 2,5 engine. then i changed to 58 and got 15 hp more....

Udo

Well, for some it doesn't matter..

If it´s tested on the flow bench, the bench was probably out of calibration, and the person doing the work was doing it all wrong.
If it´s tested on a dyno, the dyno was probably badly calibrated and thereby giving false results.
If it´s tested on the strip and ends up giving you more top speed the photo cells on the top end were placed in the wrong place, giving you false results.

Each to his own. There´s many roads to Rome.

What were the (before & after) dyno numbers? What was the engine combo?

Hi Udo, I was talking about trimming the ends of the screws, not the shaft itself. Just had this done to my carbs last weekend.

HAAH !! ;D

Well, this certainly created a discussion. But the discussion is not done on the correct basis. This modification is NOT based on power gains alone. It is just as much based on a "need" to get especially the newer Spanish IDA´s to run smoother on the street.
What this mod does, is smoothing out the transition from idle to full load much better than conventional aux venturies. The reason is that the vertical transition actually does not atomize the mix as good as the newly developed "nozzle" in lack of a better word.
On top of this you get the improovement of roughly 19 CFM @ 24" compared to conventional aux venturies, which converts to roughly 5 hp on engines set up in street trim. By that I mean no super radical cams compression etc.
Yes we can pull about 240 hp out of stock 48´s and about 275 out of 51,5´s on a good day. Problem is, most of the guys that buy this upgrade are already pushing those limits. So they see it as a relatively cheap way to gain another 5 - 7 hp and some top end speed on their race engines, because they could´nt care less about driveability. For them its all out. From what I know about airflow this mod will be progressively more efficient the closer you are to the convetional limit of the IDA´s. That part is relatively simple dynamics.

We are now heading into dark winter, and it will be some time until we can go out and test on the track. But I know 2 racers that bought this kit, and both are pushing the limits of their IDA´s as it is. Both will go on the dyno and make before & after pulls to determine ecactly how much the gain is on their engine.

The stacks doesnt achieve anything special. But they look good  ;D And fit well. So the guys that buys JayCee stacks now have an alternative.

Personally I´m hoping that this system will also be developed for new spanish etc IDF´s, because they SUCK! BIG time with the emulsion. And I will aid in that if I can.

T

Not really. Whoever dreamed this "modification" up does not understand fluid dynamics, the coefficient of discharge, the concept of the theory of the coefficient of discharge, and Bernoulli's principle of air flow velocity.

This "fix" just defeats the function of the Weber 48IDA.

Here is the basic question: The Weber 46/48 IDA has been around since 1962. The concept of flow dynamics such as flow velocity and flow discharge go back to the Roman engineer Frontinus who designed the water transmission system for Augustus Caesar. Torricelli improved on the effects of pressure (which ties to the use of the auxiliary venturi and main venturi and air speed velocity through a constricted orifice) in 1643.

And doesnt somebody think that, given the last almost 50 years of the IDA being used, somebody would have thought about this before?

Fluid and Flow dynamics have not changed in over 2000 years. One would think that Weber's engineers most likely were trained in fluid and flow mechanics.

Amazing. A new discovery in fluid mechanics in 2011. Sorry to disappoint the designer of this "modification" but I am not convinced. Removal of the auxiliary venturi compromises the transition design of the 48IDA and makes it unusable on the street. Passini talked about this way back in 1968 in his "Weber Carburettors" books.

"I reject your reality and substitute my own."
Adam Savage, Mythbusters.

Interesting. So you are substituting your own theory of fluid and flow dynamics for historical mechanical engineering? That would mean that every pipe that transmits water, every sewer that transports waste, every water transmission line in every farm, hamlet, town, and city world-wide is designed in error.

I am sure that the Mythbusters (both of them) might have a problem with your thinking.

However you are certainly entitled to that thinking.

Sorry ´bout that, the quote just made me think of you.  :D

As for fluid and flow dynamics, you clearly know much more than me(and anyone else on the Lounge) about the subject. I´m just an amateur who bought something that improved the horsepower output of my engine as seen on back-to-back testing. I´ll leave the theoretical stuff to you. I´m sure you have a good explanation on the increase in top speed.

With all due respect to you, you might read-up on the design of the internal combustion engine. Horsepower is the output of the compression of a mixture (air and fuel in the right combination) in a measured area with a set volume (cylinder and cylinder head). That is to say, the higher the compression the more the power output. The direct byproduct of this is cylinder heat. The carburetor is only a metering unit as it mixes air and fuel in the necessary proportions (the carburetor does not create horsepower as you state) and distributes that mixture to the cylinder through the intake manifold. Air flow through the carburetor does not have a direct relationship to increased horsepower (you cannot put more mixture into a confined area with a set volume capacity and expect more horsepower). Increased output is the product of higher cylinder pressure (hence higher cylinder wear) .

The best example of why this modification will not work is to watch an aerodynamic test in a wind tunnel. The flow of an airstream over a car body is the same as a liquid flowing over the same design. The flow characteristics  and properties of fluid and air, although of different densities, are very much the same.

Rather than use a kph factor as a test, the more telling test would be your engine on a dynomometer with standard weber 48IDAs tested for ouput at every 1000 rpm increase through the rev range up to 8000 to 10000 rpm. We add sensors to measure air flow speed through the carburetor barrel at the four points in the carb barrel that Weber did their measurements (it is in their technical manual). We then install your carbs with your modifcations and replicate the test.

My guess is that the air flow rates through the standard 48IDAs (with both the auxiliary and fixed venturies will show a greater (faster) air flow through the carb barrels of the standard 48IDAs versus your 48IDAs without the auxiliary venturies because of the design characteristics that the Weber engineers incorporated some 50 years ago. We are talking flow speed and not horsepower here. We are talking the discharge rate through the main venturi here.

Lastly, removing the auxiliary venturi completely compromises the Weber design and function as it eliminates the mixture enhancement through the transition phase from idle to low rpm to full out run.

The bottom line is their your carbs. You can do whatever you think is best to them. But dont you think that the designers at Weber working with the engineers from Ford and Porsche and Ferrari, the three manufacturers noted for their use of Weber carrburetors on their competition cars at the time, would have figured this out?

Just thinking out loud.....

peabody, here........

You can do whatever you think is best to them. But dont you think that the designers at Weber working with the engineers from Ford and Porsche and Ferrari, the three manufacturers noted for their use of Weber carrburetors on their competition cars at the time, would have figured this out?
[/quote]

Engieers at Ferrari, Porsche and Ford have NOT invented everyting to a level that no one else can improve on it.
I normally do not take this approach on a  forum but in this case I will, in my mindset, you have an attitude problem that will not bring you forward in what we need, an open mindset.
The world is maybe not flat, maybe it is not even round.....new discoveries are done every day.
Back off and accept that there is something new in this approach for Weber 48 IDA.

I will only listen to you, or alternatively if someone else proves this wrong by practical back to back tests.
IF that happens, I will be first in line to appologise.

As in Professor Peabody?

Sounds like you look at weber downdrafts and see a square barrel where the rest of us see a round barrel. the test methodology for this "mod" is laid out above. to be done on the dyno.fluid and flow dynamics havent changed in 2000 years. this "mod" will not work and slows airspeed flow through the barrel. there is a reason why Weber designed the DCOE and IDA carburetors the way they did and including the auxiliary venturi stacked on the main venturi. What you are also saying is that Weber didnt know what they were doing all these many years when they were producing a wide variety of carburetors for all different applications.

thats ok. keep dreaming. afterall, you have rather rare Webers....they are square barreled. :)

I rather like Sherman.....

Sherman always had an inquiring mind, dont you agree?  :)

Anybody know what the dinner special is at denny's?

Engieers at Ferrari, Porsche and Ford have NOT invented everyting to a level that no one else can improve on it.

And pigs fly....oops the Boeing engineers are wrong on the aerodynamics of pigs ;D

chicken fried steak,mashed potatoes, and veggies-raspberry iced tea. sundae for desert ;D

Ever looked at a jet engine on todays modern jet planes? air going in the front creating thrust on the exit....look at the engine pod on a 747.....its a larger version of the venturi in an ida or for that matter, any weber carburetor......I know.....you dont fly

"So we finally got to see a live flow test on JPM Dyno Day. The gain by switching from a "conventional" venturie to JPM´s vents and stacks was 19cfm!
The size was 42mm both on the old and new."

Have you read the whole thread, or just post #1? These tests were made on the same wet-flow bench that were used to develop the venturies.

Sorry, didn´t catch why top speed can´t be a measure of change in horsepower. I even thought that a dyno was measuring change in speed and the time it takes to make that change.

1964, actually.

My printed sheets are dated July 1964, Shelby told me that it was late 62/early 63 when he first saw the 46IDA set upon a porsche motor at the factory.....He was alreadywell along on bringing the AC bodies into the states.

So I guess what you're saying is if you swap out a set of IDAs for some 36IDFs, the engine will make just as much hp?


I can't believe you posted that.

I bet he was looking at IDMs.  Most people can't tell the difference.

AC Cobras were being fitted with 48 IDMs in 1963.  

And over at Porsche, the first 904s that were sold in late 1963 for the 64 race season had 46 IDMs.

I did. The problem with your statement is that the measurement of flow is not the same as airspeed. Two vary different functional elements. that is why Weber engineers measured flow at the top and bottom of the venturi as well as shape the nozzle in the auxiliary venturi to enhance airspeed. not flow. there is a reason for the internal shaping of a venturi-to enhance airspeed. Flow is quantity-it is not airspeed. airspeed is the quickness through a metered portal.....again look at the jet engine pod. Top speed is always a function of aerodynamics and the movement of air around a shape-the body is always pushing air-the sleeker the faster-the comparison: put abone stock early 911 motor in a bus and test it for top speed in a straight line ala Bonneville. Take the motor out and put it ina type 1 body and road test over the same distance in a straight line-what do you think is the fastest car? the bus or the bug? Another example: the early 356s had vw motor/transmissions but were much faster than bugs with the same power train

It's the actual physics that don't change... but the laws we write to define them are rewritten as soon as we find faults with them.

The way you are talking OC1967 I can see no need for the Nascar teams or F1 teams to do any development to their airpumps... they should just read the book, or buy a Ford engine.
Hell even Weber changed the design of the aux venturi thru the years... must have not have read the book right on the first attempt??
Holley makes several types of boosters... why aren't they just doing it right?

I believe there is a long list of reasons for why Weber designed such a CFM robbing booster in the first place.
First of all the carburetor was large enough for anything they were fitted to... if one is to little, fit four! - Today many people have engines that are on the absolute limits of what the IDA48 can handle, especially if the engine is of a "low" cc.
It's much more expensive to machine a venturi such as JPM's, as opposed to casting something that will do the job - it involves a lot of testing and fine tuning.
They made the carburetor to fit many different applications, some engines have strong pulses, some have weaker. - JPM makes stuff for the VW stroker engine mainly, so he has a much more defined application than the boys in Bologna.

I salute anyone developing new stuff for our old cars, stuff with a performance purpose, and best of all, it's not available in blue or red!

Bruce, probably a difference in your understanding of cobra history. Shelby brought over white bodies without motors. Ford 260s installed in LA. As to what was installed by AC on whatever motor they were using before Shelby had them manufacture white bodies for him, I dont know nor do most cobra enthusiasts. not in their orbit.
As to the 904s, the 597 4 cylinder carrera engine was installed versus the 904 gts which had both 4 and 6 cylinder motors. the 6 cylinder motor had the ultra rare 46ida 3 barrel carburetor (not the ida3c) while the upgrade kit from the factory included the 46ida 2 barrel downdraft for the early production 904s with the 4 cylinder motor first tested in August 1963 at weissach (3 prototypes).

Bruce, my typo. meant airspeed through the carburetor and not air flow (measured in quantity)-two different concepts. As to your earlier comment, the carburetor is always the last piece to the motor design. at least it was when carburetors were used. Again, the carburetor is a large metering unit fitted and matched to the design of the motor. It is a large metering unit dealing with quantities of fuel and air and combining them in such a way as to produce maximum power output of the motor design and components. Hence the importance of balance amongst the variables-the main venturi, the idle jetting, the air correctors, and the main jet since these parts all are part of the metering function.

thats fine. I realize that you have a perception of webers and holleys and carburetion in general. All your points have been answered in print and in design over many years. And yes that does include the question of why weber incorporated the auxiliary venturi into both the IDA and DCOE carb designs. It isnt to boost power output. By the way, please enlighten us with the various other applications (that is other cars and motors) that the 48IDA was used on. I for one am curious. As to your other points, I could address them. I too agree that innovation is to be valued. However, I stand by my position that removing the auxiliary venturi makes the carburetor thoroughly intractable on the street at idle and low to mid range rpms-again airspeed through the barrel. :)

After all, its just opinion based on fact....isnt it?

You are right, it's there to boost the signal to the carburetor on low rpm's. Without having to put to much work into it. Well, JPM has put that amount of work into it and are now, CNC machining it at great expense - so now you have the choice; same or better function, and higher CFM.

OR, better functionality/drivability and the SAME cfm as your current setup....  meaning you can now run a much smaller venturi and still have the same CFM as a much larger one.


As am I, my point was that Weber made carburetors and sold it to whoever wanted them.

Ever looked at a jet engine on todays modern jet planes? air going in the front creating thrust on the exit....look at the engine pod on a 747.....its a larger version of the venturi in an ida or for that matter, any weber carburetor......I know.....you dont fly
[/quote]

The fact that continue to you come with these statements proves your attitude again. I was pissed of yesterady for such a stone-age attitude, looking at what has been posted and that you still go on just makes me smile.

Flying?
I built airplanes duirng 1975-1980. My last year I had evolved to be part of the final test program due to some of my inventions.
Today I do not fly everyday, just a Platinum frequent flyer. In fact in about two hours I fly from Barbados to Trinidad and then onwards on another flight.
I know your comment was not related to the real reality if I fly or not, but I just had to.It was too funny for me not to answer ;.) Over and out....

Now by the way and I know Johannes is not claiming that he invented this, he just adapted it and manufactured.
ADV is not new.
http://speedtalk.com/forum/viewtopic.php?p=114043&sid=c056963d110096a4fc8cc1944e05e9ca

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by #84Dave » Sun Jun 08, 2008 12:58 pm

Alan...... we performed the very thing you discuss with a pair of 50DCO side-draft Weber's we run on a full-race, roller-cammed 2.0L Ford 4-cylinder. We removed the booster and standard venturi(choke), then manufactured what I call an ADV (annular-discharge-venturi) that runs the full length of the carb throat. The formula's that we used? For the holes in the discharge ring, we measured/used the area of the standard booster discharge 'hole'. We then found/calculated that [9] annular discharge holes, .062" in diameter, would equal, plus 3-4%, the area of the standard discharge hole on the 50DCO booster. That's what we used. The diameter of the venturi? For good 'snap' off paved-oval corners, we decided to flow the carbs with standard venturi's near 80% of the throttle blade base diameter. We had flowed the carbs with standard 38/40/42/44/46 mm diameter chokes and decided we needed an ADV that flowed nearly the same as 40mm & 42mm chokes(~80% of 50mm). Subsequent to milling a lot of aluminum, cut-and-try, we found that a 36mm diameter ADV flowed dry air right at a standard 42mm choke/booster. So....... for short-track paved ovals, we manufactured 36mm ADV's. They worked well beyond our wildest expectations! And the most amazing thing? The 'main well' signal at the ADV was 33% better than the same signal with a 42mm choke/booster. Which led to a jetting situation. Even though the 36ADV flowed dry air as well as a standard 42choke/booster, if I jetted the carb for the 42, it was pig rich. So I wound up jetting about the same as a standard 36-38 choke. I contribute the jetting situation to mixture QUALITY(annular discharge) and signal strength. Then we got wild and crazy! One of our tracks was the very high speed Mesa Marin (now bulldozed) 1/2-mile @ Bakersfield, CA. Nearly WOT with a 1000rpm operating band around the track. We built 38 ADV's specifically for that track. The 38 ADV flowed dry air about the same as a standard 46 choke/booster. And the main well signal was 37% better with the ADV. Over [3] seasons and [6] races @ Mesa Marin, we were undefeated with the ADV's. Bottom line? If our Weber/ADV experience is any indicator, and we had the machining capability/time, none of our carbs would have a booster...... even the Holley's! Dave

One more.... I love this one.

I recognise a lot of wordings...do you?

http://www.carcraft.com/techarticles/116_0508_carburetor_showdown/viewall.html

Here is just one chapter out of the article.

Booster Basics
All carburetors work on what is called Bernoulli's Principle, named for the 18th century scientist who discovered that pressure is inversely proportional to velocity. That means that as air speed increases, its pressure decreases. By tapering the carburetor inlet, air speed increases and pressure drops. This taper is called a venturi. The differential between the atmospheric pressure in the float bowl and the lower pressure in the venturi pushes fuel through the main jet and into the airstream from an outlet in the venturi.

Stone-Age carb designers quickly realized that making the venturi large enough to flow sufficient air reduced inlet velocity, which reduced the low-pressure signal, so they created a small

venturi inside the larger one and called it a booster, since it boosts the pressure drop. The booster is used to increase the "signal" or pressure differential especially at lower engine speeds to help move calibrated amounts of fuel from the float bowl into the engine.

Changing the shape and configuration of the booster affects not only how much fuel is added to the incoming air, but also how this fuel is distributed within the intake manifold. Today you can buy carburetors that flow huge volumes of air, but larger carburetors generally don't respond well at low engine speeds, so street-engine carb selection is often a compromise between max power and part-throttle driveability.



Read more: http://www.carcraft.com/techarticles/116_0508_carburetor_showdown/viewall.html#ixzz1jKtDV5Is

One more carburator that does not work.....I think it might just be a sales pitch...or?

http://www.jetworks.net/blackjack2.htm

The best part is this guys test page.... both his explanations and pictures.

http://www.jetworks.net/blackjack3.htm

Frallan, is you`re flight delayed?  :D

Here is a video from the development phase of this project. Before the jetting was completely optimized according to Johannes at JPM.
http://www.youtube.com/watch?v=4Bzqo7gzY0I

I like your concern.. :-)  Not that I know about being delayed. It is 08:35 and the departure is 10:05.
Now it happens that my friend had an earlier flight at 05:00 and also going to T&T but his flight was not delayded but cancelled. Just met him still being in the airport.

Now I think this is a slight OT from improving the Weber 48 IDA´s.

I would´nt worry too much Frallan, after reply #62 this just became pure entertainment!  :D

Is jPM manufacturing a new auxiallry Venturi for the IDA in conjunction with his update kit? I seem to have fallen out of the loop somewhere along the line with all the banter going on. If so, is the reason to boost the low speed signal to the idles? Can someone update me please? Thanks

Uhm, what I was trying to say was that there is a need to boost the signals at low revs. Weber solved it with the booster venturi, JPM solved it with a lot of testing and tuning of the delivery part of his venturi.

He is not making a aux venturi.

Thanks JHU.

A question for Johnny... How does your car perform on the street? How is the low speed carburettion?

Thanks, Matt

Didn´t have a lot of time to test on the street after SCC last fall, but my initial impression is that it´s just the same as before. I know Johannes has the same carb setup in his blue car now, but with a 3rd progression hole. It´s VERY smooth!!

Ah, no problems on the street, quicker e.t. and higher quarter mile terminal speed. I guess it's pretty conclusive that JPM's Update kit works and the earth is no longer flat. Knowing Johannes and his dedication to engineering I doubt very much whether he would waste his time on a gimmick. Just like his camshaft designs, he has rewritten the 'book'. I personally thinks its great when people innovate and push boundaries. I take my hat off to them and salute those who dare to challenge perceived limitations.

Hello my fellow Lounge members,

This will be my first entry. So far I have only been in here reading for a few years so thanks for many great hours! But this topic finally got me off the bean bag…

You’re right, Matt! Johannes not only thinks outside the box, he’s practically living outside the box!  8)

I’m seriously hooked on high output STREET motors and that’s why I’m driving, not a typical European type 4, but a type 1 with lots of JPM bits! I’ve had two other strong engines before this one. The first wasn’t strong enough.... The second got too hot when you drove it hard. I don’t have this problem anymore in my new motor, one reason being because of JPM 230 heads.
If there’s one event I don’t want to miss then it’s the annual JPM Dyno-day!
Johannes is really exciting discussing ideas and experience with. At the JPM Dyno-day 2011 he talked a bit about what is being asked in this thread, but not enough  8) ;D ;D In my opinion he’s simply too serious and nice about his work/products. You’ll never hear him brag about it…and that’s a shame...... Because it’s always at racing/dragracing you get the most noise about the bits! And yes, with the JPM products you WILL be faster on the track, but it’s in the streets you will really notice the difference!!!
At the Dyno-day 2011 we got there the day before, as usual…just to put Johannes under more stress. He’s busy preparing for the day after, but with the right technical questions you can always make him talk…he he. And of course a friend and I saw Johannes’ new venturi get tested in Johnny Steiro's car at SCC last summer, and naturally we questioned him till the cows came home. I was very sceptical, was it really possible to open the IDAs for more flow, without affecting the lower powerband? In theory you lower the air velocity and then it runs unevenly and gets less sensitive in reaction at lower rpm.
Questions, questions, questions…in the end he ordered me into his blue ´1303! Then we drove around for a long time, and Johannes tried desperately to provoke the engine at lower rpm’s, in all possible ways…(It was bonecold when we started) had you told me that it was an injection engine, I would have believed you!!! And that’s how I returned home as usual from Johannes, with new stuff for my engine  ;D
Now I can only wait in despair for spring…keep up the spirit, my fellow Cal Look loungers, who for one or other reasons  move around in small circles, waiting to get out and drive!!!  :)

Magic.

Hey Magic... what a cool experience you must have had in Johannes' car. I was lucky enough to be taken for a ride in his fuel injected car when I visited the JPM dyno day a couple of years' back. That was a great ride to and from the local burger joint! Great burgers as well!

You can rest assured that when JPM does something, he does it right. Nothing would be more embarrassing for him and his engineering pride to market a product that doesn't do exactly what he says it does. And he is such a humble guy - like you say, you will never hear him brag, bullshit or stand on a soap box preaching about the brilliance of his products. Perhaps his modesty is slightly his downfall as there are many out there who talk the talk, but cannot walk the walk and still they seem to get all of the ink and a lot of people seem to hero-worship them.

And you can even call Johannes on the phone and get great advice. Top bloke  8)

Of course, I am slightly bias as I run JPM parts in my car. They work, and I have the dyno sheets and e.t.s to prove  8)

 Hey All Torqe / Matt!

He he.....  It surely was!!.. It could have lasted all night for that matter!!!  8)
Thanks for writing exactly what I was thinking! English is not my first language, so it’s hard to express your precise thoughts..... ::)

 Could your ride from the burger joint with Johannes have taken place in 2010? We were trying hard to follow you guys in some water cooled. :o  ;)
Much later that day I vaguely remember  ;D... being on a pub crawl, downtown Helsingborg with a bunch of great VW nutters from all over Europe!!!! Think we discussed big CC engines?
And Sunday morning all had a plane or a ferry to catch, but we just kept on talking, read: tell tall stories…that’s JPM Dyno-day for you! 8)

Magic.

The fact that continue to you come with these statements proves your attitude again. I was pissed of yesterady for such a stone-age attitude, looking at what has been posted and that you still go on just makes me smile.

Flying?
I built airplanes duirng 1975-1980. My last year I had evolved to be part of the final test program due to some of my inventions.
Today I do not fly everyday, just a Platinum frequent flyer. In fact in about two hours I fly from Barbados to Trinidad and then onwards on another flight.
I know your comment was not related to the real reality if I fly or not, but I just had to.It was too funny for me not to answer ;.) Over and out....
[/quote]



Best muffler ever!! ;D

Hey Magic
I think it was 2010. That was a great day and night. Really cool to hook up with such a great bunch of Europeans. Shame I couldn't make it 2011 as I would have loved to have been there. What was the biggest horsepower reading on the dyno for 2011?

Easy Answer.....
The auxiliary is a 4.5 or 5.0. Some are marked with the number, some not. The number represents the internal size, in mm, of the fuel flow passageway area in the aerodynamically-shaped arm that connects to the fuel passageway within the carb body.

In short, the "auxiliary venturi" is functionally an extension of the venturi underneath it within the carb barrel. What Weber engineers did is extend the center tube up to the top of the velocity stack. The tube divides airflow into fastest air speed (again not quantity but speed) and slower succeeding airspeed segments. What this means, in straightforward terms, is that speed through a circular tube (like a carb barrel) like a hose, water pipe, sewer pipe, etc., is segmented with fastest speed in the center of the circular device. Speed slows as you move away from the center of the circular device with the slowest speed being next to the duct wall. Picture a 100 year old tree cut down at the base-the age of the tree is determined by counting the rings from the center out. Flow speed in a duct or tube is the same with fastest flow inside the extended tube and slower speed outside the extended tube.

Weber engineers designed the fuel enrichment arm to add fuel in the center of the extended tube with fastest airspeed. Set the "auxiliary venturi" on the venturi. The tube is dead center over the venturi opening and mixture enhancement is dead center in the port. This enhancement is for engine operation at low and mid-range engine operation. The fuel enhancement operation shuts down in transition to wide open throttle. Though called an auxiliary venturi, the venturi function is contained within the main venturi.

The same tube extension design (and mixture enhancement) is used on us domestic carburetors as well, isolating fastest airspeed from slowest within the duct. It is visible in the pictures of the demon carburetors in the car craft article.

For our fellow usa friends contemplating removing the auxiliary venturi, it compromises the enrichment of airflow in the barrel during low and midrange engine operation since the fastest airspeed through the barrel and specifically the main venturi is no longer separated (the extended tube is absent). Noted UK Weber expert John Passini discussed removing the aux venturi for rallyists in the UK over 40 years ago in his Weber writings. Where rallyists are running their engines on the edge of top rpm and output, the aux venturi is not needed....But then they wanted mid range engine tractability in slow speed areas of rally courses-Hence the inclusion of the aux venturi. As Passini said then, cant have it both ways.

 
 As Passini said then, cant have it both ways.
[/quote]

I know you bought your first Weber 48 IDA in the 70´s (and so did I) and I know you are a Weber 48IDA specialist but open your mind that basically anything in this world (I do not know any exceptions) can be improved.
It includes us human beings and our mindset.
Open your mind and except that this is not a BS invention.

How can you be so stubborn?

Most of us reading this are just smiling by now. We do not undersand how come you do not give up and either accept it, or do not and be quiet, or maybe even buy  set and try yourself.
Imagine how well an AC Cobra V8 and a set of 4  sets of 48IDA and this modification would run..........this would be a fantastic thing to try.

Hate to burst your bubble but no Cobra enthusiast running 48idas will touch this "mod" that really isn't a mod at all. However, you should send them to various Weber specialists around the world and have them do the needed airspeed and airflow tests. From my emails that I am getting from people here, there isn't a whole lot of interest in this because they dont wish to compromise the original Weber design and modify the IDA body which is unstated here but would be necessary to model the 48ida operation after the car craft article about the demon carb. Facts are facts.

Orange County 67,
If you were just taking a better attitude, I am sure we could laugh and share a lot of good stuff.
In principle we have the same interest and probably a  lot of good experiences with and without similarity.
I am often in SoCal and I would love to share stories, facts and ideas with you, but only if you stop being so stubborn as you are right now.

If you go back and re-read my posting, it is a response to an enthusiast's' question about the function and design of the Weber auxiliary venturi. Obviously, their asking the question tells all that there is a lack of understanding by that enthusiast of that part. Removing the auxiliary venturi was discussed and discarded by the UK's leading Weber expert 45 years ago. Its removal compromises the operability of the 48IDA at low and mid range speeds. That was the case then and continues to be the case today. As to the privatemessages I have received about this, ?I respond that this will compromise the Weber function.

As to what you want to do, they are your carbs and you can do whatever you wish to them. Many who have inquired of me are concerned with operability and are skeptical of removing the auxiliary venturi mod on the street. They are correct in being skeptical especially when this change was discussed in UK racing circles so many years ago.

As to my experiences, I am very old school having experienced that time first hand. The folks that I hang with are purists like me and have been around the block before. We appreciate what we had so many years ago but are not wedded to it for the sake of age. That's why we appreciate what we have had for so many years and are able to spot easily things like this modification that do not result in any performance improvement for many enthusiasts.

Nothing personal with you as you certainly are entitled to your thinking and opinion. As to buying a set of whatever these modified venturies are, I will defer. I am content with the Weber design and function of the 48IDA.

Since you are in OC regularly from where ever you travel from, make sure you have a hamburger there for me. Many places to choose from.  :)

The modification JP have done to the IDA is in many ways similar to some motorcycle carb designs. And I know that Johannes has tried, tested and spent many hours on testing different motorcycle carbs on his engines (Keihin FCR, Mikuni etc.). And with great results. So I guess he has stolen one or two ideas from the motorcycle carbs....

The ways I see it, the nozzle on the new venturi creates a vortex on the back of the nozzle, and creates the needed depression in the area of the nozzle holes. And in that way it is possible to get rid of the standard emulsion set up.

Of course this can be made to work. I don't quite follow the sceptical comments. I hope the new venturies will be a succes for the 2012 season, and thereby prove itself.


/Peter

Let me get this straight: you are saying that engine depression (also called engine vacuum signal) is created is created by a nozzle and not the rotational function of the crankshaft, piston rod, and piston in the cylinder and sent up through the intake manifold to the carburetor? Additionally, that the carburetor is no longer a metering unit for the mixing of air and furel but an integral part of the creation of engine combustion equal to the aforementioned crankshaft/rod/piston assembly in a cylinder Amazing. I hope that this guy, if this design is as you say, has a very competent and experienced patent attorney.

For some of us,the earth remains round. For others, the perspective is that it is flat. Amazing. Now we see 2 stroke/4 stroke motorcycle intake technology adapted to the Weber 48IDA. Skeptical thinking just went up by a factor of 10.

Sorry. Not sellable.

I feel that all of this theoretical bullshit being thrown around is meaningless unless you have held them in your hands, tested them both in the lab and on the road, studied the results, and made conclusions based on these observations and experiences.
Now, I admit that I certainly do not have this information, BUT I can say that Knowing Johannes and his undying and relentless pursuit of High Quality components, these things either WORK, or they wouldn't be sold!

Sorry if this is too straightforward, but it's as much as me arguing there's no merit in the use of fuel injection in a T1 HP format, having never tried it ... so far anyway.

TxT

TxT

I agree with you in this regard: before you can play with them in your hands, one has to understand the design and function (per Weber's Technical Manual) and then you get to play....Its a piece of advice written by Gene Berg in the late 70s in his technical articles (especially the transmission and his comments about rod ratios and the application of V8 thoughts to an air cooled motor). Remains true today as it was then. No offense taken.
B

OC: Just wondering... Are you disputing the claim that the JPM venturies has horsepower potential, or are you claiming that they make the engine less drivable? Or both?

Well I haven't posted for some time and I didn't intend on doing so!

However sorry (well not really) OC1967W but you are making me laugh soooooooo much.

You seem to be so blinkered in your thinking take a step back and wait for some results and let them be conclusive.

Reallistically it's all about area under the curve (BHP & Torque) for the rpm range being used. That's what will make the car run faster.

So I have a set of these venturies and I'll be testing them against the convential set up on the dyno. After which I will let you know the results and the drivabilty on the road.

I will be honest in my report and then we can either acknowledge your understanding OR I guess you could be admiral and acknowledge you weren't as clearver as you thought, appologise and tell ALL your friends about the wonderful thing you've just found out!

Please don't bother with a great explaination on the matter anymore lets just wait for the results.

Be back soon!

All the best

Paul

AND??? ;D

Well I haven't posted for some time and I didn't intend on doing so!

However sorry (well not really) OC1967W but you are making me laugh soooooooo much.


You seem to be so blinkered in your thinking take a step back and wait for some results and let them be conclusive.

Don't have to wait-over 45 years of history of the 48IDA on the street and its performance on the street speaks for itself

Reallistically it's all about area under the curve (BHP & Torque) for the rpm range being used. That's what will make the car run faster.

Really? We are talking the performance of the "mysterious" fix that somehow the Weber engineers and John Passini in the UK and other Weber enthusiasts have missed over the last 45 years.....Makes sense to me...

So I have a set of these venturies and I'll be testing them against the convential set up on the dyno. After which I will let you know the results and the drivabilty on the road.

Better idea for you...since you have this "mysterious" venturi, why don't you send them to Art Thraen or Jeff Denham or Pierce Manifolds in California or Gene Berg Enterprises or offer them to the Cobra owners club for testing on the street or to PMO in LA for their IDA 3barrels for Porsches....don't forget to include the instructions about removing the auxiliary venturi and the needed modifications to the fuel enhancement circuit and the other modifications that need to be made to the carb body and let Weber experts do the needed independent testing in both street configuration and on a race motor....

I will be honest in my report and then we can either acknowledge your understanding OR I guess you could be admiral and acknowledge you weren't as clearver as you thought, appologise and tell ALL your friends about the wonderful thing you've just found out!

Sorry-removing the auxiliary venturi for increased performance was debated in England 45 years ago....great in race cars but non functional for street driving-already decided-but I am open to independent testing by people here in the states (see above for suggestions) to see if this venturi works in addition to your removing the auxiliary venturi. As far as friends and inquiries from other enthusiasts, I will continue to recommend that they stay with the tried and true Weber design for the 48IDA

Please don't bother with a great explaination on the matter anymore lets just wait for the results.

No need to...was tried years ago.
Be back soon!

All the best

Paul

As always, you are certainly entitled to make the modifications to your carburetors that you own. It is a free market and let the market place decide. Given the reality that I doubt that you will send this mod to outside experts for outside independent testing, the best that can be said is that you tried and were defeated by the design and engineering of Weber. Best of luck to you.

58VW, it seems that over 40+ years of performance on a design that has weathered time leads someone to think that some performance trick was never considered during that period.....perhaps the next performance inprovement will be ? :-\

Ground control to Major Tom...

I´m really trying to understand your logic oc1967vw.

 - You claim no theoretical horsepower gain, but I for one have experienced higher top speed at the track during back-to-back testing?
 - You claim less drivable engine in theory, but real life tests have shown same or better low speed performance.
 - Do you understand the difference between just removing the aux venturie and installing these venturies? Or is there none in your opinion?
 - What are the modifications to the carb body you claim has to be made?

As for your ideas about "outside experts and outside independent testing" - If I or Paul test something and find that it works, we´re wrong. If Jeff Denham tests the same thing with the same results he´s right? Outside of what and independent from who?

Good morning all

Let us all stop this Discussion please. I do not have an engine with 48 ida and I have never driven a car with 48 ida. So I do not have any interest in this mod - so far.

OC1967vw - I mean no disrespect - If you do not believe in this mod so be it. That is only fair.

JS - Enjoy your 48 IDA with JP mod.

Best regards Henrik Hagen

Looking forward to your results Paul!

There is still much to be learned. Just because it was tried unsuccessfully 45 years ago doesn't mean an altered approach will give the same results. I don't believe JPM to be a snake oil salesman, his and his customers results speak for themselves.

Let's keep an open mind here.

agree...sometimes i feel like that commercail from coke zero...were your just asking  "AND"...what else can you give/show me...to ones satisfaction ;D

it was the 48ida that lead me to vws....once i heard those carbs singing going down a small street in fullerton....i was hooked

JS. Your hit the nail on the head. The problem with this is that it is not "thought up" in Orange County. Ergo it doesnt work.

OC. Your so far out with your con´s that it´s hilarius. You have not come up with one new thing. You have referred to the Weber Tech manual and to some 40 year old testing that was NOT the same as what is done today. You refer to Cobra owners who wohnt touch it because it compromises the design (!) - What do we care ?  They wohnt install fuel injection either, would they. So until you come up with some productive REAL facts instead of just keep on referring to a 40 year old instruction, PLEASE PUT A CORK IN IT !

JS, Paul, Bom and other´s have seen what they can  do. And they will ALL double test on their specific engines against the dyno when spring comes. THEN you will get your solid proof from independant sources. But that will most likely still not be solid evidence since it´s done here and not in Orange County.

Outa here.

T

I for one am for new things and enjoy it when i see it...lot of people said the 4in stuff wouldnt work on the street...i guess it does ...evolution is a great thing!!

agreed....glad I didnt purchase Coke stock when they introduced "Coke Zero"

same here....pick a street in fullerton or orange or anaheim....bought my first pair in 1970-still have them

Henrik,
thanks for the posting. As I have said before, the free market will dictate the sales of this item. Putting aside the "mod" for the moment, the problem is that the impression has been created that simply removing the auxiliary venturi is one step towards increased engine performance.  In fact removing the auxiliary venturi also removes the tube inside the auxiliary venturi that sprays emulsified fuel into the airstream that enhances carb transition during low and mid speed engine operation. The 48IDA will function, as it already does, at wide open throttle as it is designed to do with the auxiliary venturi in place. I have received numerous emails already regarding this change and caution against it. Because no one knows what their modification or modified venturi does (although they reference the demon carb article), the key unanswered question is the operability of the carb at low and mid speed operation where the engine spends 85%-90% of its time when in operation.

Henrik, no offense taken. Hope that you are able to get a pair of Weber 48IDAs one day 

Alpha-Beta-Alpha testing or what is also called baseline testing. As to who can do it, I gave you recommendations. I would add the larger and more well known Weber specialists in the US because they deal with a much larger market of Weber enthusiasts.

No offense taken if you dont. I said that earlier in a previous post. :)

Agree with you whole heartedly.
I know that you made the 4in bore work for the VW enthusiast. It took a lot of development work that relied on baseline engineering that already existed (that is to say if a 92mm barrel works, why not a 94, if that works why not a 4 in bore etc.).

It then becomes a question of whether the enthusiast-consumer chooses to purchase the product, knowing the upside and downsides of it. I run 90.5s only because I want engine longevity and control over engine temperature. I don't want to rebuild a motor every year. But that is my choice as a entusiast-consumer.

If I want to purchase the 4in bore cylinder and the increased temperature that comes with increased compression that directly produces increased horsepower (that I want said motor to produce), at least I know what I can expect as a result of my purchasing decision. I can then finalize my buying decisions in accordance with what I want for said motor. Evolution is a great thing as it gives the enthusiast buyer the option of making the decision in the end.
 :)

Rocket racing,
response is above. And I do understand the design engineering involved and the operating function of the auxiliary venturi and its enrichment function. I would recommend the purchase of the Weber Technical Manual for a more elaborate discussion on its function. I am sure it is available to you were you are located.
No offense taken.  :) 

Thank God they didn't have discussion forums in the late 60's when Berg decided to try the 48IDA on a VW engine.
It would probably have been doomed by those who "knew" that Solex carbs worked, regardless of results.  I'm sure everybody would also be warned about what could possibly happen to your engine over time when using this new technology..  ;)

Would recommend you read Gene's technical articles on engine compression ratios and engine longevity and horsepower. He was a great guy. I am a big believer in the Berg philosophy of moderate compression (tho I think that Gene would moderate his comments on engine compression if he were alive today) and greater engine longevity and the impact of engine generated heat on engine life.

no offense taken :)

http://cal-look.no/lounge/index.php/topic,16934.90.html

Just thinking outside the box.

Since you state that your modifications and modified venturi enhance performance throughout the rpm range and work both at low- and mid-range engine speeds as well as they do at wide-open throttle, why don't you consider sending a set to Ray Valerio and have him test them both on the dyno and on the road in this project engine? It has Weber 48 IDAs and is well constructed. He can/will have baseline engine performance figures using standard configuration Weber 48 IDAs and can easily run your venturies and make your recommended carb mods (assuming they don't involve any physical mods the IDA carb body) and conduct the parallel testing and independently and conclusively determine whether there is a performance improvement with your modifications and venturies. An added plus is that he is in northern California from what I can tell from DSimas's videos and not from Orange County.

We can then see first hand the independent results and all VW enthusiasts running Weber 48 IDAs will benefit. Again, experimentation is a good thing.
Don't you agree?
 :)

You may not have done your homework to realize that these engines, as has been the case all along ... even as Gene admitted to the case of the 94mm cylinder, run in perfect function in a perfectly streetable configuration with no 'over-heating' problems or premature rebuilding needed ... as always, When properly designed and assembled!
Now, your transmission may exhibit other symptoms! ;)
TxT

TxT, Precisely what I was saying......While Gene constantly emphasized the best piecesmatched together will produce the best performance, he alsoset limitations and engine size for T1s and Ts (because of heat) in order to give the consumer-enthusiast the best logevity for their dollar

and you are right about the trans

no offense taken. you and I are thinking alike.
 :)

true...although i did not do all the work...my good friend mr denham did...well...at least his version of it...for the street...there are plenty of people pushing the envelope...im just riding along giving him moral support..we all need that now and again...if only i had an extra 100k laying around!!...could be fun!! ;D

OC1967vw No one’s been on the moon.
Scientists proved that more than 100 years ago. Do you think scientists didn’t know there stuff back then
Konstantin Tsiolkovsky a well-known scientist did some calculations back in 1903 on using a cannon for space travel. He concluded that a gun would have to be impossibly long. The gun would subject the payload to about 22000 g of acceleration. That is about 1000 times that the 20-30 g the human body can handle for a few seconds. Find a history book and read it yourself.
No one’s have walked on the moon, and no one’s ever will.
Bin there done that end of story.



http://www.youtube.com/watch?v=-erjci4JzoA




Sorry OC I couldn’t help it  ;D ;D ;D I just don’t think you know exactly how the JPM venturies work.
Have you looked at his website?  http://www.jpmotorsports.se/products2
No offense taken.

You´re not answering the question, just saying you know how the original system works... Try reading the question again.

I normally don't post in the racing section as i have no idea what anybody is talking about as it always get far too technical.

But this either works or doesn't, so i will wait and see.

IDA's get mods that weren't in the original design.  For example 3rd progression hole.  increasing the inlet bowl by removing the wall.  And using glass needle valves.  These might or might not be needed, but they have been proven to work for certain engine combinations, allowing them to either perform better on the street or strip.  I know some people say the 3rd hole is not necessary if the carb is set up correctly etc, but clearly it overcomes some problems so people use it.

Anyway can we start the bickering and lets go race.

Why the hell would I want to "send a set to" someone?  ???
If Ray or someone else wants a set they can bloody well buy them from JPM like I did!!!  ::)

I absolutely agree that experimentation is a good thing indeed. That´s why I have done so, backed by theoretical calculations, flow bench tests and dyno sessions.

This reminds me about the threads on some US forums back when JPM released the MS230 heads. Many of the "Good ol' boys" claimed that over 230 street driven hp straight out of the box was impossible. We know different now, don´t we...  :D

When Jpm took what is essentially V8 camshaft design (aftermarket hot VW cams) and modified it to better suit the characteristics of the air cooled VW engine, his design was belittled on Amercan forums, yet dyno testing and road testing clearly proved that the design was superior and did in fact increase horsepower. This was achieved by reducing nasty harmonics and therefore valve float whilst at the same time reducing the need for excessive valve spring pressure, yet still allowing huge rpms.  Now this is in direct contradiction to Berg's writings in his tech manuals where he cites the need to use triple valve springs on the Berg car to achieve high rpm in order to control the valve train. This was a 'cure' back then, when the computer aided technology was in its infancy and not widely used as it is today in all aspects of car design and tuning. I am not dissing Berg here, just suggesting that technology has come a long way since his involvement in our scene. Oct67, if you need proof of his cam designs, then I can send you before and after dyno sheets of my turbo car and how it responded to Jpm's cam. The crux of it is I picked up an extra 225 horsepower. There will be scores of people on this forum who can also post their hp gains, of this I am sure.

The MS230 cylinder head was also belittled by Americans and why? It is a superior design for road and track use that has greater cooling qualities than even a standard Volkswagen design. It is designed from the outset to tackle inherent problems that arise when tuning Big cc a d high compression VWs - namely the large increase in heat and the cylinder head's ability to dissipate it. It also features a five rocker stud setup that deals directly with the issue of rocker studs pulling with high spring pressures. And of course the high flow characteristics straight out of the box. Again, this product works and can verified by people on this forum and myself soon when I finish a 4" bore turbo motor I am building with MS230 heads.

The IDA Venturi mod... This product is fairly new, but has seen a massive amount of design and testing and is being used by people on this forum who conclude 100% that the mod works at both low speed, road driving and foot to the floor et chasing. Again, this product was designed with the help of the latest software able to simulate flow even before the end product is machined and installed. Weber engineers and their slide rules 40 years ago were not privy to such tools and were they at the time, I am sure they would have come up with a similar design.

The crux of this argument has taken a deviation I believe. Originally it was an interesting debate that I watched with interest, only able to offer encouragement as I personally have no experience with the mod myself. However, as the debate progresses it is now has the potential to taste of propaganda and I agree wholeheartedly with Torben's quip: "if it ain't made in America, it ain't worth shit." What I dislike about what is being suggested here by Oct67 is that it has the potential to be very damaging to Jpm and people reading this post may well be put off purchasing his products. It has the potential to sink the ship before it sets sail. We need innovation and the fact that folk these days are running seeming never ending quicker P.b.s is testament to the fact that things evolve, move on and get better with design.

Oct67, I mean no disrespect to you as you are obviously well qualified through your own experience and are very articulate in putting your points across, but I can't help but feel, as the argument goes on, that  you have an ulterior motive.You seem overly passionate about dismissing this mod.  Does the Jpm mod threaten your business directly perhaps? Or are you just being patriotic, defending the American domminance in the VW scene from foreign innovation?

My VW/porsche engine builder has been building engines since the mid 70's.  thats over 30 years experience with all the latest products over that period of time.  He has raced in all forms of VW/Porsche racing, his latest project is restoring a salzburg rallye vw.  This includes a dry sump that has been engineered using cnc technology from the original design.  and....using a special jpm raptor cam grind not available off the shelf.

He is a typical grumpy old engine builder, but he sings nothing but praise for JPM products.  So much so he convinced me to ditch my webcam and scat followers to JPM cam and lifters.  He knows these work with less spring pressure, thus causing fewer problems and this will increase my engine life span.

The companies and builders in Europe using JPM products have an excellent reputation that they wouldn't want to harm, so the products must do what they claim.

great post  :)

Seconded,

I have found this thread a compelling read,

I am yet to understand why testing done by a selection of europe's best is not comparable to testing that OC67 wants to take place in the states? Why do you feel that something tested widely across several countries in europe will be flawed where as something tested in the US and particularly a single state of OC will be gospel?

OC67 the more i read of your posts, the more i feel your using out dated and historical documents to back up your attack against a new innovator, Johannes is doing great things for our scene and should be commended. The fact is life moves on and documents once thought of as gospel do get superceded by more modern idea's. (Or is the world still flat???)

Innovation is fueled by people that dare to think outside the current NORM and seeking improvements that most think is unattainable. I have much respect for the originals such as Gene Berg etc who without which the scene would not have developed the way it has, but I am sure that in there day people thought what they were trying to acheive was impossible and again am sure there would have been people such as OC67 telling them that they were talking shit and to stop persuing the avenues they were experimenting in.

I am glad that true innovators pay no attention to the nah sayers and carry on regardless. ;D

isnt califonian red wine better than the french stuff now?
bet the french never saw that coming  ;D

Very intresting topic as long as it kept on technical level.
As it comes to OC1967VW technical comments I also wondered how it is possible to achieve same pressure differences without the venture pipes..

But when i look at the recommendations that JPM gives and compare them to Weber recommendations for same throat diameter they are smaller. I don't remember the emulsion tube numbering but is not the F2 e-tube one which leans out on the upper part?
So it seems that JPM has come up with nozzle placement in the venture that has much stronger pressure difference than Weber where able to do with theire design.

I don't think this is impossible with today's CAD and fem programs because you can model hundred different models moore than they where able to do by hand before..
It's always about the cost. Maybe the conclusion by Weber in 1960  where that full throttle flow improvement where good but partload should bee optimazed. Maybe it was not costwise clever to try and test out a new design for only 19cfm which could bee achieved by just make the carburetor bigger..
To optimize the ventury design in 1960 would have include one engineering to calculate one year to come up with same calculations that you are able to do in couple of days with modern CFD program.
I don't know if JP makes his simulations by him self but the cost today is much less than it was 10 or 20 years ago..
Basic educations in flow knoweldge is enough.

That's the only difference from engine technology during last 50 years. Computer programs use precise same mathematics as engineers used in 1940. It is only much faster and Moore cost effective nowadays.

Same comes to camshafts. JPM camshafts are not from technical point of view so revolutionary. They are just calculated bu rules that where defined decades ago. It is just that others camshaft grinders did not have this possibility and therefore copied working profiles without the knoweledge of precise valvetrain dynamics..


To design high perf parts is simple mathematics nothing moore..  The art is then to combine this things in the right way..



 

LOL!    ohh man, this is cool! ......  ;D ;D ;D ;D ;D ;D

Hmmmm,

God knows why I'm going to post again  ::)

This will be the last time before I post up the results!

OC1967VW

You have NO respect for anyones opinion on this subject unless it can somehow back up YOUR understanding.

1) I have no interest in this product unless it delivers performance on the street & strip PERIOD!

2) I have never subscribed to the whole Gene Berg thing, sorry he did many great things. However If I read and believed everything he said I'd be running 8.5 to 1 CR and stock heads. The fact is I've run comp eliminators on the road since 1996 and they are still on the car and it's never overheated  ;D I can also think for myself and I don't anyones approval.

3) With the greatest respect to all the open minded non arrogant nice Americans. Sorry but this product doesn't need the USA's approval! Lets think a little:
Webber 48ida's - Italian
BRM, Speedwell - British
Berg's Cranks - Swedish
Flat Four designed - Germany

Very European wouldn't you say?

4) I purchased my Beetle at 17 without any knowledge of Cal Look or the fact they could be be modified to go fast. I was not motivated by the Gene Berg or Dean Lowry etc... In fact I just didn't want a Ford Escort or a Fiesta like my friends and I thought the VW Beetle looked great and was cool...that's it.
Then I went to Bug Jam and was just fascinated by how fast a VW could be. I was inspired/stunned by John Brewster & Julian Rose.

5) I have spoke to Maclaren F1 and from now on all parts will be sent directly to the USA your approval, as they're now in total disarray after discovering none of their parts will work otherwise!  ::)
BTW, You probably don't know what F1 is, it's regarded as the pinnacle of motorsport in small circles mainly everywhere outside of the USA (the rest of the world). For the record most of the F1 teams are UK based with as far as I know Europens engineers and by all accounts they have done OK!

6) Perhaps your head so far up your own backside you can't see the light!

For those who are interested in knowing the FACTS not FICTION I will report my findings with total HONESTY and then you can make your own mind up!


Kind regards Paul

It's OK, Paul.
Last time I checked Texas made up a Hell of a percentage of the USA, and I'm here to say that Johannes is The Man when it comes to NEWLY Developed technology for the air-cooled VW.
Call me a fool, but I follow him just as I do AND did in the past for Gene Berg Enterprises, and others with innovative developments for our Small, but Highly Focused scene in the world.

I for one, will be VERY Interested in Your findings, but have to admit that even after you've submitted, there's a chance I'll have to retest for myself ;)
My only wish, is that JPM was CLOSER to me! My wish would be both GBE and JPM where located next to my shop, in the same complex ... of course, in this scenario, Jeff Denham & I would already work together ...
Everybody says, "Small world", But I wish it were even smaller.

OnO,
TxT

My take on this thread is not any longer only technical for me, it is breaking down the Atlantic and breaking down regional/country borders.
I will not comment any longer as all my arguments and more too, are nicely reflected by others.
Apart from the main technical topic, this thread has added value to me.
Thanks!

well said. ;D

Mr TXTOM...

if you could get Mr Denham to move to Texas (the second biggets state..haha) i would go back to cali and help him move!!!

sorry,...back to the regular programming

Oct67vw... Here's a link to the product on JPM's website: http://www.jpmotorsports.se/produkter2
You may notice that he has registered the design with the authorities and a patent is in process.
Maybe sometime soon the penny may actually drop? Regards, Matt

i was thinking about dusting off a pair of my IDA's, nope gone stick to my EFI ;)

Good thread boys,

I'm sure Johannes would have tested this combo to death. as he don't sell dress-up parts

I know I'm looking forward to see Pauls A/B testing on this setup, but i think we already know what the results will be.



Picture from my antique cabinet

(http://i32.photobucket.com/albums/d18/autocraft/cb3cee58.jpg)


I know i shouldn't post anything when I've had so little sleep...... lol

Martin , that is antique but nice , our cars are also antique , so it is ok. EFI is more for watercooled engines  ;)
If you do not want them longer let me know ...

Udo

lol,

Its ok, i'll keep them there just the right size to keep pens in ;) better with the JPM Mod, as i can get more pens in ;)


hey just thought its my car's 60th birthday this year, your right its antique ! lol (oh and water cooled lol ) still sticking with the EFI, although its a bastard drilling the injectors with the extra progression hole!


Hope to catch you at the track this year be nice to see your new car ...

I think we will meet , 2 times in england this year .
One engine with 51,5 and one with 58 carbs.  ;)

Udo

Hey Matt

sorry for the late reply!! But yes. it was a great day and night! ( and it's always cool to get a face on your fellow lounger....!) The 2011 Dynoday Was a little low on horsepower (compared to previous years) if i remember correct, it was a great Swedish guy (sorry, can't remember his name. someone help me!) with a cool, silver oval bug. It showed 220 + somthing bhp. (help me again with the correct number please!)
This year, I'll come in my aircooled, and put it on the dyno. ( mayby I should bring my old venturies...... just to compare!!! ;) But maybe it's a waste of time.... not being The US of A?? ? ?? ;0)

Magic

Look forward to it Udo. i'll just stick with the 112mm turbo, that Carb stuff confuses me, i don't have a Weber manual so I'm confused on there workings...  :'(

Talking of JPM IDA-parts... I also installed 38mm JPM IDA-venturis and JPM-velocitystacs on my Ghias 1.6 rallyengine.  My engine is working best on high-rpm:s, not easy to drive. But after this modification it really runs from much lower rpm very flexible and does not need any help by kicking the clutchpedal like before, when rpm went "too low"(under 4000) at different rallysituations. Now it works like mild street-engine also when we drive between the specialstages on normal roads. It goes up from 1500rpm without problems.
At racing rpm:s it feels much more agressive and really runs better when driving. At dyno it went from old result 142hp to 146hp at 7000rpm. Engine run 8600rpm very easy and dropped very little maxhp near 8000rpm. That 7-8 area we will try to develope next with modifying the exhaust. Inside there is JPM-dualsprings working 100%.
We have tested and developed this engine many times and these parts were absolutely the easiest to see that difference
on flexibility and the difference of answering the gaspedal, which was huge also.   

Nowadays there is not many places where you can buy really bolt-on high quality raceparts as from JPM. VERY GOOD work again Johannes!


Summer dragrace, winter rally ;D


Jussi
 

Did you also drill the third progression hole? As Johannes recommends that right?

very nice,sounds like they really worked,but you know you have to take you rally car to USA to be tested before anyone will believe you :o ::) ;) :D



cheers Richie

Jussi!

Never met you but it feels like I know you. Fun.
Excellent feedback. Thanks. Now you convinced me to also add it to a small engine I am building. Impressiive.

Guys, let us park the discussion of were to test stuff. On this topic it is only one small street in Southern California that seems to have an issue.
I really do feel the atmosphere between all our global corners are being erased on thsese forums and we show more and more respect.
That is really a good thing.
I am amazed to see the good stuff in Slovenia, Bulgaria, Middle east, Asia, South Africa and Down under places, jsut few examples...we all have something to share, add and learn.
Now back to the topic!

Yes...ship the car over here...let me test run it...then maybe i will believe...actually...can you send about four cars...may take a while....lol

How are you international open minded American guys doing with this?
Has anyone bought a set and tried back to back in USA?

I really wish one or more of you takes the step and try it.
Few days ago another very successful story came to my knowledge. I will not share the details myself but i do think the owner or a friend of him will soon.
The Swedish guy is  friend of mine and VW Drag racer and also owning a very nice super beetle that he drives on a daily basis both on the street and once in a while on the eighth mile.
I.e. when I talked to him, he was all smiles. He knows his stuff and he has zero reason to BS.

I have asked JPM Johannes for a set to update my Jaycee 51.3 mm carbs.
We will run back to back in July and I will for sure report good and bad experiences.

How about you?

Any news... 

Henrik Hagen

Have used my car on the street for the last weeks, might have something with the switch to F20 emulsion tubes, but the flat spot on the carbs is less noticeable with the new venturies. In other words - they work great on the street!

Hey JS,
are they f20's?
i thought Johannes suggests f2's?

Peter

He may recommend different tubes for different applications. I went from F2 to F20.

Paul, any results from you're testing? These seem to be working very good for people. Think I will have to purchase a set.

OC1967VW, will I have to drive to California to get them verified for use on my VW and so you and some "famous" people can see that they work for real?

Well maybe at least on the drive ill get better fuel consumption with them  ;)

Look forward to fitting these to my IDA's, street driving is sometimes horrible around 2000-2500rpm

Regards

Stef

 I have allot of respect for JPM and the products he has developed . If he made or sold junk parts or parts that did not live up to his claims he would have been called out a long time ago, don't remember that happening. I have never owned any of his products but that was more about who I was working with on projects rather than the product. I believe everything can be improved on and I guess I am lucky to still believe I can learn something new every day. I respected Gene Berg alot but unlike OC1967vw I know that Gene made mistakes just like everyone else and opinions are only as good as the info they have at the time.  To condemn a product without ever testing it yourself is either very bold or stupid depending on whether it proves to work or not. I hope JPM continues to develope new products along with all the other innovators in our VW world. Ed  why don't you do us a favor and introduce yourself and tell us who you are and what your qualifications as an expert are so that next time someone comes out with a new product they can check with you first about the viability of it. Mike McCarthy

OC1967vw .... I think you are most knowledgable in all what you have said.  But apperently i don't have any respect with your knowledge because you use your knowledge to defend someone that doing innovation. theory is use to support what you are doing. if you just talk all day long with your theory and doing none.....what useless time you spent

Go to coffee shop and continue your theory all day there and blame someone that doing good for others

i can't think of anyone not wanting to use JPM valve train and heads or parts in their motor(s), other than money issues.  ;D

JPM is and has been doing great stuff for our little VW industry, think about this, a small shop dedicating all this R&D for a "niche" Type 1 engine?

Hi,

I'm thinking about buying a set of 42mm JPM venturies but in consideration of the investment I'd like to have some feedback from people that have used them on a regular basis, street/strip use.
I'd prefer real back to back figures/facts about hp/torque increase rather than "general" driving impression.

Has anyone of you done such testing ? Are they fully plug & play or do you need to make any massaging or mods to the carbs before fitting them ?

Thanks

Phil

The venturies themselves are 100% plug and play. I have only had the chance to do back to back testing at the strip.

Thanks for your reply JS.

I have read I don't remember where, that they required mods to be fitted.

And were the improvments on the track, OEM vs JPM venturies ?

And what about JPM's stacks ? Do they improve flow compared to OEM stacks ? How do they compare to Bergs or Jaycee's ?

To be honest, I had some of the first ones made, the "pin" that centers the in the groove of the carb body was about 0,2mm too long and I had to spend a few seconds filing them down to make them fit more easily. That "snag" has long since been corrected.

For strip results, read further back in this thread. It's good entertainment, thrust me!  :D

As for the stacks they flow about 1-2cfm more than stock, so not really. What I have understood about stacks it's not all about flow but also about the design of the stack. They should be pretty straight and have a curve at the top of the stack. This is to help the pulse "turn" at the top of the stack. I'm not sure stacks that looks like a wide "V" in profile helps that in the same way(They look cool though). Many F-1 engines have straight walls it seems.

Jaycee claims on his website that his stacks alone improves flow by 21cfm. I'm not sure how that's possible(A 42mm JPM venturie gains 19cfm over a normal 42mm). This is gained by getting rid of the secondary venturie that's "in the way" of the airflow. Likewise, the small increase in flow on JPM stacks comes from them being a little larger inside diameter compared to original ones, not the shape as such. You will of course need to tune the total stack-to-valve inlet lenght regardless of what system you go for.

I am really out of my depth discussing these design details, but I think they are very interesting and hope that the more experienced engine designers of this great forum can chime in and give their opinions!  :)

This year has been a laying low season for most of the serius racers around here due a healthy mix of lack of time, lack of funds and damaged machinery.
I am however certain that "we" will come back strong in 2013. And also provide some back to back power data regarding these upgrades.

But, like I menthioned way earlier in this thread, this upgrade does not deal with peak performance alone, but just as important to make the IDA carb work better on the street. The few, apart from the man himself, that have tried them on the track consistenly reports a drop in ET of 1 to 2,5/10´s along with the butt feel of better pick up power. What that relates to in HP I do not know. your guess is as good as mine. But if we relate to the increase in carb flow alone, then 19-21 CFM improovement should equal about 5 hp as a rule of thumb. The closer you get to the max performance of the carb the better numbers. So whhen the time comes I´m sure we will see power gains ranging from a few hp to about 10 hp.

T

JS and Torben, thanks for your input.

The fact that these venturies not only improve the top end rpm range but provide something across the rpm range makes them an interesting addition.

As for the stacks, I guess I'll keep the original ones for the time being.

A small question, hope somebody knows this.
When I visited Johannes on my way to SCC this summer, he was testing some JPM venturies in Weber 45 DCOE carbs,
but is he thinking off making those venturies also for 44 IDF's or 45DRLA's carbs?

Regards Edgar

I know he is. I do think that it is mainly a question of getting the time to develop them, - and need for it. The day he has his back against the wall in a certain combo, they´ll get developed. That´s the curse of being a one man army.

T

Ok thank u Torben.
I will wait patiently  ;D

Regards Edgar

Does anybody have more info/updates already?  Back to back tests?  I really want to know more because I'm willing to try a set.  Do I need bigger jets or just swap the venturies?


Thx,

Dem

So here is finally my report.
I meassured my 2,1 Typ 1 yesterday on the dyno.
The engine has 51,5 IDas and a compression of 15:1 running on race fuel.

With standard venturies 44mm and Jaycee intakes it was 245 hp.

With JPM venturies 44 mm and intakes it was 262 hp.

I use 170 main jets normally in i ended up with 175 with the jpm venturies.

Both versions were tested 3 times on the same dyno witout take the car of or something else. the runs
were in between 2 hours....

So a very interesting result!

See the dynosheet attached!

Cheers,
Basti

Congratulations on awesome dyno results!!

The percentage hp gain from the venturies is along the lines we estimated on my old engine. Cool to see it documented!!

Good results!

Almost 125hp/l - VERY nice! I look forward to reading OC1967vw comments after this.

-BB-

Very interesting result :)
So the jpm vents and 'intakes' added 17BHP, what do you mean by 'intakes?'

Lee

He meant velocity stacks by JPM.

Tobi

That's amazing, new vents and stacks equals 17BHP

Lee

 :D

i have a set of the 42mm jpm vents and the jpm stacks going on a 2276 ida motor when its finished. looking forward to what its going to be like does anyone know if they will help all round driving on the street???


cheers andy

Basti,

Thank you.  Those are very very impressive results!  The gains are right in the RPM range many drag VWs operate in.  Johannes should expect a large increase in orders shortly.  (Including from the U.S.!)

Ron Barrett

Does he have these advertised on his website as I could be interested in a set.

That's what I have been waiting to see, I am going to try a set of them. I wonder how much cfm loss there will be with a set of the CB billet stacks.

http://jpmotorsports.se/ms/ms/j-p-motorsport-nya-produkter/ms-90000825-p-3/

With regards using them on the street, please take a look at the curve again and pay attention to the range from 2500 rpms up to 3500 rpms. This is the area where you cruise and where many experience issues (dead spot/hesitation) With the JPM parts you gain almost 20hp in this area (from approx 62-63hp to almost 80hp). You are looking at a improvement of around 30% in the most critical range for street driving.

-BB-

Hi BB,

i think the curve in this area doesn´t show the exact values and isn´t comparable as this is a full race engine
which is not running smooth and perfect in this area under full load.
So i can´t say anything regarding street drivealbility difference, sorry.

Cheers,
Basti

I understand what you are saying.... writing... and of course you`re right. Far more important than the actual increase is the curve.

Anthony,
I would use both his vents and stacks just like Basti did.  Your setup is very similar to ours and I would be very interested in the results.  I would dyno your engine with the current setup (48IDA's I believe w/42 vents), then 51.5s W/44 vents, (Joe would probably lend you a set) jet the 51.5's for the best HP and then install the new 44 vents and stacks on the 51.5s.

You might even want to try some 44 vents in your current carburetors first.  I think there is a couple of more horsepower available there.  That way you'll know whether you want to order 44s or 42s.

Ron Barrett

We have used those JPM parts in rally now 2 seasons and the engine has been much better. Now we put those also into 1400cc Mini circuitrace car with one  48 IDA> got 4hp + 15nm more in dyno at once and runs much better on driving...Cheap developing in racing

Jussi ;)

It took a while, the anodizing used leaves a pretty rough surface when stripped. I sanded them on my lathe to get the surface close to finished. 

An unanodized option would be nice. they look great polished though.

pics

Beautiful Anthony.  Are those the 48's or 51.5's?  Can't wait to see your dyno and track results.

Just 48s. I see a trip to Jaycee in these carbs future.

I dont know that they will be Dynoed anytime soon, I will tune them with an O2 sensor at the track.

Anthony,

Did you get the 42 or 44 vents?  Good luck at he track and let us know what improvements you find. 

Ron

Now I'm really interested... this is where a lot of compromise is made running the 48IDA on the street.

44s

I went with Johannes reccomendations. I'm drinking the cool aid. He recommended the 51s too, and they will probably be coming this winter.

These vents will work with either. It's not like regular 51s where you need to buy a bigger OD venturi to keep the vent in place because when the throttle plate area is opened up the standard vent would fall into the throttle blades. But if it is already opened it will work fine because they hang off the aux vent registers. The bore above the venturi that the stack normally fits in is now the carb throat, making a bigger variation  in bore size to the choke which I am guessing is what creates enough signal to suck the fuel out of the bowls.

They are really very clever. I'm glad I got the stacks too. It all makes perfect sense. They just look like airflow...although I am not sure Bernoulli's principle works the same here as it does in Europe. At least I am closer than Southern California.

After the October ASA race I may send them to Joe to play with if he wants.

 ;D

Zeroing in on the setup. Initial impressions driving around is that with about 4 stops for various jet changes is that it already drives as good as my old setup. I did one belt off pull from 4k to 8200 in 3rd and after the rich spot from the accelerator pump cleared out it held 12.7 afr until I let out.

Track time Friday night.

So far I am "well chuffed"

Anthony,

I saw you went with the 44's, were your "normal" venturis also 44's or smaller?

42

so you gained top end power and the car remains streetable, even at lower rpm's?

what are your engine specs?

Ass dyno says yes, I picked up power. I will find out at the track Saturday. Never been on a dyno.
2387, big stock style heads, big cam. Lotsa compression. Race gas, marginal street car, mid 11s.

Good luck Anthony.  We'll be real interested in what your times at the track are. 

 ;D

here's a clip the JPM Dyno Day #10

http://www.youtube.com/watch?v=kTDR7Use9vU

VW T1 1302L 1972

2332ccm
210 PS @ 6410 rpm
252.3 Nm @ 4700rpm


JPM MS230 Cylinder Heads: Alloy 356, T6 kvalitet 48x38mm Manley Typ 4 ventiler.
JPM Rocker 1.45
JPM 00408 Raptor kam (282° 10,70mm)
Weber 48 IDA, JPM Raptor venturies og Raptor stacks
Bosch 010 Distributor
Bosch Blue coil
CSP Python 45mm exhaust

Well done. I remember when I started racing about 22 years ago that this kind of power was only found on full on drag engines. How times have changed.

Indeed, making this kind of reliable power while retaining heater boxes and fan belt is truly amazing!  :o

Hi Anthony,
                How did these perform at the track?

Thanks

David Gouk

I only went once. My tuning was off. I plan to put it on a dyno as per Johannes recommendations and  get the A/F right before my next outing.  I would have gone again but I broke the pinion bearing (my builder says it is the only one he has seen break) in my trans, eating the case and R&P.

I still went a personal best, but the MPH was down. It was way fat. I was relying too much on the A/F gauge. If I had just pulled a plug out...

I'm chopping away right now trying to get another 50 pounds out of it without it looking like a race car.  

Eivind:  May I ask what CR is your engine?  Also, did you test the Raptor venturies/stacks versus the stock IDA stacks?

The reason I'm asking, is that I have a similar engine in my '68 Beetle:  2332 cc, 10:1 CR, JPM MS230 heads, 1.4 rocker, JPM 06908 Raptor cam (274° 10.8 mm) and am always interested in tuning this combination further.  Thanks!

this might help getting the floats correct: http://www.thesamba.com/vw/classifieds/detail.php?id=1570935

Did anybody ever answer Bruce's question about needing to change emulsion tubes to get best gains from the venturi/nozzle mod? Just curious. From what I have been learning and playing with, using the wrong tube can really chip away at how the car responds.
Or are these working best with typical F7 / F2 choice?

I used F20 tubes with my 44mm Raptor venturies
There are some jetting recommendations on JPMs website
http://jpmotorsports.se/ms/ms/j-p-motorsport-ab-produkter-helsingborg-254-68/ms-90000825-p-4/#Raptor Venturies (http://jpmotorsports.se/ms/ms/j-p-motorsport-ab-produkter-helsingborg-254-68/ms-90000825-p-4/#Raptor Venturies)

Happy New Year to all of you  :)

Car is in the workshop, but I believe I´m also using the F20´s.

F 20s here as well.

Since I've got F2's already installed (one of JPM's recommendations according to your link), I'm going to start there first with the 44 mm Raptor venturies.

I hope to get the Beetle on the chassis dyno in a few weeks, but we're buried in snow at the moment ;)

Ooooooo, Neil is drinking the kool aid too!
Your carbs are still 48 mm butterfly, correct?

Yeah, I guess I'm just copying you Anthony...first I buy your wheels and now the Raptor vents ;)

With the JPM  MS230 heads and Raptor cam kit, I'm sort of gradually building a Swedish engine.

Yes, my carbs are the original Italian 48 IDA's, except with third progression hole and enlarged float bowls by Jaycee.  However, I might try to experiment and test a bit with different stacks and the Raptor venturies...I prefer to make one change at a time, and then check the results:

1.  Original Weber IDA stacks that fit "inside" the carbs;
2.  Geers stacks that have the full-size opening and fit "on top" of the carbs.

With the auxiliary vents removed, I'm curious as to how the two types of stacks will perform.  I may try Raptor stacks in the future, when budget limitations have eased.

Hey Neil, not that my combo is the same as yours but switching from stock IDA stacks to jaycee stacks cost me 3 peak and 2 average hp on Roger Crawford's dyno.  Motor is 2210 ccs and made 227 hp.

Thanks for the information.  My Geers stacks are somewhat similar to the Jaycee, from what I've seen, but there have been a few varieties produced:
(http://i39.tinypic.com/2qvwns6.jpg)

The jpms have a real similar profile to stock, just bigger.

There is a lot of really interesting information out there with regards to intake bellmouths. I recommend that you you google: "Prof. Gordon P. Blair intake trumpets" and download the pdf. Poor a cup of tea and enjoy the read before you remove the Jay Cee style stack covers and throw them in the garbage.

-BB-

I know that JPM tested several designs both on the flow bench and on the 1-cyl R&D dyno before going into production. As "Prof. P. Blair" states in his article the advances are not massive, typically 1-2hp compared to an original IDA stack.
I cannot help myself thinking there´s a reason modern Formula-1 engines use stacks with a "simple radius design", not massively "V" shaped like some VW suppliers sell.  :)

What's wrong with blocking off air to the air corrector jets ? ??? ;) ;)

What do you mean Darren?

Here's a comparison of my 44mm Raptor venturies compared to the typical/stock Weber vents:

(http://i44.tinypic.com/2ludtmg.jpg)

Update:  Been driving for a couple weeks now, with the new Raptor IDA venturies (44 mm) and I'm very pleased with how smooth the engine is during street driving.  Since the snow has finally melted, I'm hoping to get on the drag strip next Friday to see if there is any effect on ET and top-end speed.  Hopefully get on the chassis dyno soon, as well.

Just noticed on one of the GT40 forums that some of the Cobra crowd are now using the Raptor vents...

Well, the stock IDA stacks don't work well with Raptor vents, as they seem to vibrate...perhaps removing the stock auxiliary vent destabilizes the stock velocity stack (too loose).

So, I decided to install the Raptor stacks.  Very nice quality with a precision fit.  One interesting aspect, is that the Raptor stack has just a small lip that slides inside the IDA bore, and lines up with the main wall of the bore.  This should make for a smooth flow down to the venturi.

The Raptor stack is larger than the stock IDA stack at the top, so the dust covers needed to be modified.

I also picked up some 1.85 mm fuel jets to experiement as per Johannes jetting recommendations.

(http://i60.tinypic.com/fne529.jpg)

Spot on, Neil. The "ideal" is as you´ve found out also to run Raptor stacks. You gain 2-3cfm as well.

i really curious to know about you ET with these raptor stacks and venturies.
i saw a youtube movie where the auxiliary vents where removed as well.
what is the exact purpose in fact for them?

henk!!!

Well, I went to Castrol Raceway (Leduc, Alberta, Canada) last night for the weekly Street Legal drag races.  I have been routinely obtaining ET's of approximately 12.8 seconds at this track, and only twice have I ever managed a 12.7 (once this year and another time two years ago, so very rare).

In my first race last night, the Beetle pulled off a 12.6174-second quarter mile at 109.04 MPH, and this was into a slight head wind.  The 60-ft time was 1.7710 seconds, one of my best ever.  My previous top speed was 106 MPH.

The track elevation is 730 m (2,400 ft) and the only other 12.6 ET I've ever achieved was at sea level (Mission Raceway, BC).  Could the Raptor venturies and the change from 180 to 185 main jets have resulted in a 1/10th of a second improvement on the ET?  Maybe.  They certainly didn't hurt ;)

Here's an iPhone picture.  It's not crystal clear, but you can see how the stack blends into the top ledge of the bore, for a smooth transition:
(http://i57.tinypic.com/2q8pojn.jpg)

Sounds about right. "We" typically see ET reductions of 1 to 2 /10´s on the quarter once the carbs are dialed in.

T

The top speed improvement sounds comparable to what others have gained also.

I went back and looked at my time slips and the improvement in ET was actually 0.16 seconds and top speed increase was 2.9 MPH (4.6 km/h).  Nice improvement ;)

Now I've just got to remove some mass from the Beetle, as it's currently 925 KG (2,035 lb) with driver on board.  Might have to strip the interior a bit...

Oh brother, here we go again.  ::) ;D :D

Hi Johnny,

please explain...! ;)

Tobi

From JPM´s Facebook page:

"New product under developmet "Raptor Powerjet". A third fuel systemet for IDA carb.
Makes the power band wider with a lot more power in low to mid range and also a few ponies at top. Reduces the richness when throttle is opend suddenly at low rpm. Works very good with Raptor venturies and stacks👍. Pictures are just on prototypes for testing."

More pictures at his FB: https://www.facebook.com/pages/Johannes-Persson-Motorsport-AB/178561615658940

That idea is stolen right out of the 48 Dellorto Trijet. But if he can make it work with IDA´s, so be it  ;D

Looks like we will have something new to discuss on Dyno day.

I´m allready thinkin´, what if this can be used as a methanol injection (?)   ::)

T

Exactly what you said Thorben,this is also the modification that Doug Berg did on their 58 carbs,on Ron Flemmings superstreet engine they made close to 20Hp (if not more?) can't remember exactly what he told me, with all the mods Doug did on the carbs only  :o

Anyway hatts off to Johannes he's still doing more development,and everybody can take advantage of it,if they buy his products,those who don't...will continue to be slower  :D

UHH! don`t put such thoughts in my head. I promissed myself that I would take a step down from all this. My mind is working overtime again  ;D

T

Johannes has used Mikuni carbs on his other engines, and Mikuni pioneered the use of powerjet set ups in motorcycles:  http://classicmotorcycles.about.com/od/serviceandrepair/fl/Power-Jet-Carbs.htm

Yes, I prefer the Keihin version personally.
 ;)

But well done JPM for adapting it to a common auto application.

So, I'm experimenting with the Raptor powerjet kit on my new 2332 cc.  I received some initial jetting recommendations from Johannes, such as reducing to 170 main jet and starting with 100 powerjet. Since I may not be able to get on the Dynojet for a while, I'm wondering what some of you ended up with for final jetting?

Lots of these powerjet kits have been sold, as mine is from the latest batch last month. However, other than a few instagram pictures, I haven't seen any feedback on jetting for the drag strip. Maybe there's some info on other message boards in different languages, if you can share with me.

Thank you!

I'm interested to hear of progress on this as well.