2276 IDA jetting

[Stefan Rossi]

Hello, I realize this has probably been asked quite a lot but I cant find any info on my specific setup.

I have been the to rolling road 3 times now and its becoming a joke. The guy cant jet the IDA's right at all!

I went to HiTech performance, just outside of Birmingham (England) and I had to get the car recovered to him as it was so un-drivable under 3000rpm. I have since heard more horror stories of similar things happening. Obviously he's not a good guy to take your VW to! He was almost telling me off for running IDA's on the street, said it was impossible, I thought this is strange as I'm sure thousands of Cal lookers run them on the street.

My setup is:

2276cc
9.5:1
fk 89
CB 044 supper mags
48 IDA's, third progression whole and 37mm venturies

I cant remember what jets he has put in nor did he tell me (I will take them out tomorrow) but its runs very rich when I put my foot down, black smoke out the back.

I just drove the car to Spa and back and it was not a very nice drive trying to cruise at 60mph with the people I was with. I guess because of the cam as well, between around 1500 and 3000 the car just stumbles and smells very strongly of fuel. All out from idle is fine it runs fine when its on the main circuit, its just the transition from idle to mains its having trouble with (i think)

The whole problem has escalated from my IDA's trickling fuel constantly on idle... I have managed to get number 3/4 side to stop it but 1/2 side still trickles constantly. I run at 8 degrees BTDC at the moment. I think I need more to stop this problem?

Fuel pressure is 3psi

Im about to strip the engine, fixed a broken pickup pipe and hone the barrels that have been washed by the amount of fuel on idle and replace the rings for some total seal gapless ones.

I don't want to rebuild the engine with the new rings and have the same problem and have to replace them again.

Does anyone run the same setup as me and have a good idea of what jets and timing to go for to stop the trickle at idle? I have already tried filling the accelerator pump rods and the one carb still does it...

I drive the car on the street a lot and it's becoming really unpleasant to drive now.

Thanks

Stef

[Lids]

can't help with the jets, but i have a set of NEW 94 total seal rings i need to get rid of.

[Stefan Rossi]

I already have some gapless ones I got when I was living in Canada but thanks anyway dude 

[Lids]

no probs.

Look here: http://cal-look.no/lounge/index.php/topic,19044.0.html and then compare yours.  Should give you some idea.

[Stefan Rossi]

Okay thanks

[Shane Noone]

Hello, I realize this has probably been asked quite a lot but I cant find any info on my specific setup.

I have been the to rolling road 3 times now and its becoming a joke. The guy cant jet the IDA's right at all!

I went to HiTech performance, just outside of Birmingham (England) and I had to get the car recovered to him as it was so un-drivable under 3000rpm. I have since heard more horror stories of similar things happening. Obviously he's not a good guy to take your VW to! He was almost telling me off for running IDA's on the street, said it was impossible, I thought this is strange as I'm sure thousands of Cal lookers run them on the street.

My setup is:

2276cc
9.5:1
fk 89
CB 044 supper mags
48 IDA's, third progression whole and 37mm venturies

I cant remember what jets he has put in nor did he tell me (I will take them out tomorrow) but its runs very rich when I put my foot down, black smoke out the back.

I just drove the car to Spa and back and it was not a very nice drive trying to cruise at 60mph with the people I was with. I guess because of the cam as well, between around 1500 and 3000 the car just stumbles and smells very strongly of fuel. All out from idle is fine it runs fine when its on the main circuit, its just the transition from idle to mains its having trouble with (i think)

The whole problem has escalated from my IDA's trickling fuel constantly on idle... I have managed to get number 3/4 side to stop it but 1/2 side still trickles constantly. I run at 8 degrees BTDC at the moment. I think I need more to stop this problem?

Fuel pressure is 3psi

Im about to strip the engine, fixed a broken pickup pipe and hone the barrels that have been washed by the amount of fuel on idle and replace the rings for some total seal gapless ones.

I don't want to rebuild the engine with the new rings and have the same problem and have to replace them again.

Does anyone run the same setup as me and have a good idea of what jets and timing to go for to stop the trickle at idle? I have already tried filling the accelerator pump rods and the one carb still does it...

I drive the car on the street a lot and it's becoming really unpleasant to drive now.

Thanks

Stef

Hey Stef,

I'm new to IDA's myself and found a lot of info on IDA's here on the lounge and elsewhere as you'll probably come across once you start looking. My experiences of IDA's are similar to yours as far as trying to get them set up for street and strip. The good news is it can be done !!  On the flipside however they are a lot more fiddly to get right and sensitive than other makes of carbs in my experience. One thing that crops up time after time is getting your float heights set up correctly as per Weber specs and just making sure the carbs mechanics are working as evenly and positively as you can and the balance is as close as you can achieve in terms of opening and closing etc before you address any jetting changes.

Once your happy with all that, you mention terrible to drive at low speeds. You are on the idle jets up to around 3000+ rpms's before the transition to main jet stacks occur. The over rich condition from idle ( black smoke ) is probably too large idle jet for the Venturi size.....with a 37mm choke maybe start with a 55 idle jet ( the holder is probably 120 ) but also check your main jet size and emulsion tube and air corrector.  With your fuel dripping, this seems to be a common problem on IDA's...I had that too but actually it stopped all of it's own accord mysteriously after a while. Some say it happens a lot when your cam has a lot of overlap ( which your FK89 does ) and at low speeds this causes pulses that trick the carbs into dropping fuel and that is why some guys seem to advance the timing at idle or idle speed to overcome this. You could also try dropping your fuel pressure ( even though 3 psi is fine and I actually run just under 4 psi at idle without fuel bleeding past the needle's ) to say 2 psi just to see if the dripping eases. If not back to 3.

Am sure you'll get loads of advice from guys on here and elsewhere that have experience on IDA's and can help you sort this but this is just my experiences so far and I have recently tuned mine on a rolling road and I do drive to the racetracks, race and drive home again, with 51 IDA's and 44 chokes !! So it can be done !!!!  But yes it does help to use a rolling road engineer with experience of tuning carbs. There must be somewhere in your neck of the woods that can.

Also noticed your only running 9.5:1 squeeze with the FK89. That is conservative and won't make that cam feel very lively. Personally I think 10.5:1 is a minimum on pump fuel to wake it up.

All of the above just my two cents worth and hope it steers you in the right direction.

Shane.

[leec]

My IDA constantly dripped fuel into the inlet when a bit of dirt got in to the jet/fuel inlet. A good clean with air line/carb cleaner sorted that. I was worried about bore wash but it was clearly coming straight out the exhaust port.

Agree with Shane about compression ratio but that's something for the future to change.

You need to find someone local to you who knows IDA's, my car has run best when Frank and Martin have set the carbs up (I'm no good at it at all!)

Will try and dig out my jetting specs, not too disimilar spec to yours:)

Lee

[ibg]

Floats #1, syncronised #2, I like 15 -  20 deg or so initial advance as long as it starts ok. You'll need to mod the distributor so there is maybe 10 deg in the distributor. More initial helps smooth the transition. Then sort out the idle airs and jets with no main stack in the carbs, a wideband really helps get into the ball park. Just drive it around and try different combo's. I had 130, 120, 115, 110 idle airs. My engine likes 110 or 115's and jets 60 - 65. some people can get them to run smooth on 55's but not me. Always fine tune the mixture screws when the engine in HOT.
Then go to the dyno and work on your main stacks: emulsion, mains and airs. and your 'all in' ignition timing, now you are spending the money where it counts, on power.
The Idles are still flowing when the main jets are working so get the idles right first other wise you fiddle on the idles and stuff your main stack settings you just paid money to sort out.
I have a 2387 with 44 vents and its very drivable, but I worked at it.
tools: float gauge, 'snail', idle airs and jets, wideband. Not sure what you pay for dyno time over there, but here OZ all these tools are worth about 3 hours dyno time, and you know 3 hours sometimes doesn't get you far  

[Jesse/DVK]

First check that your valves are adjusted, your fuel pressure is correct and adjust your float height (very important!) and your idle timing (10 or more degrees) so you can close your throttle plates to stop the dripping.

If you can provide us with your jets and emulsion tubes we could give you a direction.

[Stefan Rossi]

Hey, thanks for the replies. I am at the workshop now, my valves are fine and fuel pressure is no more than 3psi, may regulate it to 2psi.

I will check my float levels. Do I need a special tool for this as I've seen mentioned?

I will advance my static timing to 10 degrees, would you say no more than 32 total? You can limit total advance on MSD dizzys with different bushes I'm sure?

I remember about a year and a half ago I found out it was the cam causing the pulsations and tricking the carbs in thinking you were trying to accelerate! I haven't seen the car for a year so I had forgot about that! Thanks for reminding me!

So my jets in the carbs now are
F16 emulsion tubes?
140 mains
200 airs?
Idle airs 120?
65 F10 idles?

I think I've got each one correct for what it is?

I have spare

180 airs
55 f10 idles
160 mains

Thanks for all the help so far,

Stef

[Stefan Rossi]

Hey Stef,

I'm new to IDA's myself and found a lot of info on IDA's here on the lounge and elsewhere as you'll probably come across once you start looking. My experiences of IDA's are similar to yours as far as trying to get them set up for street and strip. The good news is it can be done !!  On the flipside however they are a lot more fiddly to get right and sensitive than other makes of carbs in my experience. One thing that crops up time after time is getting your float heights set up correctly as per Weber specs and just making sure the carbs mechanics are working as evenly and positively as you can and the balance is as close as you can achieve in terms of opening and closing etc before you address any jetting changes.

Once your happy with all that, you mention terrible to drive at low speeds. You are on the idle jets up to around 3000+ rpms's before the transition to main jet stacks occur. The over rich condition from idle ( black smoke ) is probably too large idle jet for the Venturi size.....with a 37mm choke maybe start with a 55 idle jet ( the holder is probably 120 ) but also check your main jet size and emulsion tube and air corrector.  With your fuel dripping, this seems to be a common problem on IDA's...I had that too but actually it stopped all of it's own accord mysteriously after a while. Some say it happens a lot when your cam has a lot of overlap ( which your FK89 does ) and at low speeds this causes pulses that trick the carbs into dropping fuel and that is why some guys seem to advance the timing at idle or idle speed to overcome this. You could also try dropping your fuel pressure ( even though 3 psi is fine and I actually run just under 4 psi at idle without fuel bleeding past the needle's ) to say 2 psi just to see if the dripping eases. If not back to 3.

Am sure you'll get loads of advice from guys on here and elsewhere that have experience on IDA's and can help you sort this but this is just my experiences so far and I have recently tuned mine on a rolling road and I do drive to the racetracks, race and drive home again, with 51 IDA's and 44 chokes !! So it can be done !!!!  But yes it does help to use a rolling road engineer with experience of tuning carbs. There must be somewhere in your neck of the woods that can.

Also noticed your only running 9.5:1 squeeze with the FK89. That is conservative and won't make that cam feel very lively. Personally I think 10.5:1 is a minimum on pump fuel to wake it up.

All of the above just my two cents worth and hope it steers you in the right direction.

Shane.

Hey Shane, thanks for the help, I kept it at 9.5:1 because I do a lot of street driving and thought this would be a lot safer? Also now I want to eventually run a 40 or 50 shot of nitrous at the track. I may consider bumping up to 10.5 tho now if it will still be safe with the nitrous and not overheat on the street?

What temps do you see when driving? The highest iv got is around 215-220.F and that was in Belgium on a hot sunny day and giving it some too! I have external cooler but removed the fan as I've never had to use it! Might put it back on now as 220 was a bit high for my liking...

Also what heads are you running?

Sorry for going off the subject a bit, my main priority is to get it running/driving nice 

Stef

[ibg]

the 120 idle airs and 65 jets are in the ball part and should run OK with correct mixture adjustment. Drive around a bit with no main stacks and see if they run nice to 2500 - maybe 3000 rpm without a lean spit or black smoke.
F16 emulsion is unusual, I would think F11 or F2.  I have dynoed F7, F11, F2 and F2 is best on my motor with 160 mains.
I have read F16 delays the mains leaving a big hole between the idle circuit and the main circuit and are very rich up the top end

[Shane Noone]

Hey Stef,

I'm new to IDA's myself and found a lot of info on IDA's here on the lounge and elsewhere as you'll probably come across once you start looking. My experiences of IDA's are similar to yours as far as trying to get them set up for street and strip. The good news is it can be done !!  On the flipside however they are a lot more fiddly to get right and sensitive than other makes of carbs in my experience. One thing that crops up time after time is getting your float heights set up correctly as per Weber specs and just making sure the carbs mechanics are working as evenly and positively as you can and the balance is as close as you can achieve in terms of opening and closing etc before you address any jetting changes.

Once your happy with all that, you mention terrible to drive at low speeds. You are on the idle jets up to around 3000+ rpms's before the transition to main jet stacks occur. The over rich condition from idle ( black smoke ) is probably too large idle jet for the Venturi size.....with a 37mm choke maybe start with a 55 idle jet ( the holder is probably 120 ) but also check your main jet size and emulsion tube and air corrector.  With your fuel dripping, this seems to be a common problem on IDA's...I had that too but actually it stopped all of it's own accord mysteriously after a while. Some say it happens a lot when your cam has a lot of overlap ( which your FK89 does ) and at low speeds this causes pulses that trick the carbs into dropping fuel and that is why some guys seem to advance the timing at idle or idle speed to overcome this. You could also try dropping your fuel pressure ( even though 3 psi is fine and I actually run just under 4 psi at idle without fuel bleeding past the needle's ) to say 2 psi just to see if the dripping eases. If not back to 3.

Am sure you'll get loads of advice from guys on here and elsewhere that have experience on IDA's and can help you sort this but this is just my experiences so far and I have recently tuned mine on a rolling road and I do drive to the racetracks, race and drive home again, with 51 IDA's and 44 chokes !! So it can be done !!!!  But yes it does help to use a rolling road engineer with experience of tuning carbs. There must be somewhere in your neck of the woods that can.

Also noticed your only running 9.5:1 squeeze with the FK89. That is conservative and won't make that cam feel very lively. Personally I think 10.5:1 is a minimum on pump fuel to wake it up.

All of the above just my two cents worth and hope it steers you in the right direction.

Shane.

Hey Shane, thanks for the help, I kept it at 9.5:1 because I do a lot of street driving and thought this would be a lot safer? Also now I want to eventually run a 40 or 50 shot of nitrous at the track. I may consider bumping up to 10.5 tho now if it will still be safe with the nitrous and not overheat on the street?

What temps do you see when driving? The highest iv got is around 215-220.F and that was in Belgium on a hot sunny day and giving it some too! I have external cooler but removed the fan as I've never had to use it! Might put it back on now as 220 was a bit high for my liking...

Also what heads are you running?

Sorry for going off the subject a bit, my main priority is to get it running/driving nice 

Stef

Stef, no worries, glad to help where I can.

With your jetting. To be honest every motor may respond differently, so it's hard for anyone to say "use this jetting" but we can all guesstimate what may be close....As you mentioned black smoke at low speed etc I presume it's rich and possibly the idle jets are too large for the rest of the carb configuration. I mention starting with 55 idles as you can always drill them larger from that point if you need too ?  Regrads the rest of the jetting....in my opinion, you really need some equipment to monitor what's happening to the AFR across the rpm range and make changes accordingly for best overall performance especially as a street driven car and not pure race.

My Heads are Competition Eliminators with 46 x 38 valves and CR of 11.2:1, I run with an FK87 cam so have less duration than you. My oil  temps on a typical road journey in warm weather are 95-100celsius. I do have an external 19 row cooler and electric fan to draw heat off which I do use when oil temps are looking to climb above 100 !!

Good Luck getting it sorted. Didn't realise you a member of DKR as well so hope to see you at Action if your coming ? Come over and say Hi  

Cheers, Shane.

[Shane Noone]

Stef,

Just checked the jets in my IDA's and this is after a rolling road session where we made lots of changes to try and get maximum power with a safe AFR flat out.

As others have said sometimes on a street driven car you may want a safer AFR throughout entire range. Mine is good mostly but goes a bit too lean around 5000rpm. That's ok as I will only momentarily pass through that rpm on the way up and down and not sit there for any length.

As an illustration to how every motor will respond differently my final jetting with 51 IDA's and 44 chokes was 60 idles and 120 idle airs, 175 main with F2 emulsion tubes and 180 air correctors.  Most guesstimates would never suggest a combo like this but in my case this worked out best.

I agree with what ibg says re the use of F2 emulsion tubes. Others have found the same. These replaced my existing F7's and made a huge positive difference !!

Thinking about your setup, you could say with 37mm chokes run around 150 mains and 180 airs as a starting point. You have some spares like you could try 160 mains and 200 airs. Like ibg says you can drive around on just the idle jets without mains in the carbs and try and tune the 65's with the idle mixture screws but one thing to think about is the choice of idle jet does continue to influence what is going on when on the main jet stacks, or so I have been led to believe.......but I am just a novice with IDA's so I will leave the sound voice of experience to those who have played with and run them for years 

Shane.

[Stefan Rossi]

the 120 idle airs and 65 jets are in the ball part and should run OK with correct mixture adjustment. Drive around a bit with no main stacks and see if they run nice to 2500 - maybe 3000 rpm without a lean spit or black smoke.
F16 emulsion is unusual, I would think F11 or F2.  I have dynoed F7, F11, F2 and F2 is best on my motor with 160 mains.
I have read F16 delays the mains leaving a big hole between the idle circuit and the main circuit and are very rich up the top end

Wow that is defo the problem then, thats exactly whats happening! I wont be putting those F16's back in then.

I will try the to drive it around with no main stacks then, first I need some F2's F7's or some F11's, preferably some F2's if you or Shane have any spare?

What HP were you getting at the wheels and at the flywheel Shane? I got 154hp and 147ftlbs at the wheels with a stock box on stock mounts and no mid mount or toque bar. Im hoping for a bit more now i have all these things on the car holding it all in place

Thanks again for the help

Stef

[Shane Noone]

Hi Stef, if you can't locate emulsion tubes, I got my F2's from Matthew at Eurocarb near Reading. They are not cheap to buy new that's for sure but needs must and all that. If you can get a selection of used emulsion tubes to trial and error on the dyno cheaply or the lend of from a mate then great. If you have to buy a set new, then based on my experience now at the dyno and other guys I spoke with, I would recommend F2's

Power wise, well I wanted my motor setup for maximum power and fastest ET's. This usually means big chokes in the carbs !! This will of course make it less responsive on the road at low speeds. It's combination of things that allow big power and fast ET's. You have a racing cam installed but you have kept your CR very "street"  As mentioned before on a naturally aspirated motor at least raise that to 10.5:1 plus and your powere and torque figs will rise !!  But I understand you want to run NOS at some point. Look at Danny, he is running 10.5:1 or maybe a little more now with an FK87 and uses 65 shot NOS. So far so good. Runs sweet sounds strong. Ok it's not a street and strip car, but it could be....

With 48mm carbs. If you want to go fast it is normally accepted choose a choke / venturi in either 40 / 42 / 44.  If your not too fussed about ET's and not chasing the numbers then yes stay with your 37's to make it more pleasurable and smooth driving on the road.

My power was 212 bhp flywheel with fanbelt and muffler and I think around 180 ft/lbs torque. I don't have a wheels figure but if I did it would be a lot less maybe 170 bhp?

I think for now, work with what you do have and get it running sweet and enjoy that. Then when your ready and want to chase the numbers you can go with more CR and big chokes etc. If you have 154 bhp at wheels that is probably around 190 at the flywheel which is pretty darn good for a 37mm choked IDA and what I would expect from the spec of your 2276. So it's just sorting out the mixture through the range from idle and happy days 

Good Luck

Shane.

[Stefan Rossi]

Thanks a lot for the help Shane, Ive Pm'd you back about the emulsion tubes you have.

Really cant decide wether I should bump the compression ratio up to 10.5 up or not while I have the engine apart?

After all I want the most power out of it that I can get and I know next season I will be chasing the numbers and probably adding nitrous. Thing is I still like driving the car on the street and I don't want it to just be a race car.

Stef