Improving your IDA´s...

[Frallan]

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

[Frallan]

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

[BeetleBug]

Frallan, is you`re flight delayed? 

[Jon]

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

[Frallan]

Frallan, is you`re flight delayed?  

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.

[JS]

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! 

[Fasterbrit]

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.

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

[Jon]

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.

[Fasterbrit]

Thanks JHU.

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

Thanks, Matt

[JS]

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!!

[Fasterbrit]

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.

[magic]

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!  

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  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  
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.

[Fasterbrit]

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 

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 

[magic]

 Hey All Torqe / Matt!

He he.....  It surely was!!.. It could have lasted all night for that matter!!!  
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.  
Much later that day I vaguely remember  ... 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!

Magic.

[folkevogn]

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

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!!

[Fasterbrit]

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?

[OC1967vw]

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

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.

[Frallan]

 
 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.

[OC1967vw]

 As Passini said then, cant have it both ways.


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.

[Frallan]

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.

[OC1967vw]

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. 

[PH1303]

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

[OC1967vw]

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.

[TexasTom]

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

[OC1967vw]

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

[JS]

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?

[Paul Bate]

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

[58vw]

AND???

[OC1967vw]

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.

[OC1967vw]

AND???

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 ?