How do I get the lean spike down right before WOT?

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larger pump shot/cams.

 

Tried that already, no go. I thinking it maybe the idle air bleeds ?

 

try the bleeds then. Just go smaller from where they are. It also could probably use some more main jet which can take that lean spike out too.

 

Heading to the track tonight will report back with results . Thanks.

 

I see AFRs in the 14s over 5000rpm . How much boost is it making at that point .

Dont run it at the track unless you can get the AFRs under 12:1 at WOT .

 

Looks like the A/F follows the rpm. What size HSAB's? Mine did that until I blocked the HSAB's.

 

Car ran a 8.5 @98 with a 3.4 60ft

So I get into the burnout box, start to give it gas and car pops through carb and wants to die. I keep getting into the throttle and it clears up and does a burn out. Pull up to the staging lights, brought the stall up till it felt like the brakes couldnt hold. Light goes green it falls right on its face..... car ends up turning on and it runs a slow ass time.

See the thing is the car pulls great from a roll but sucks from a dead stop

Stall is a 3400
Rear end gears are 3:42

 

Mine look like this:

Idle: 11.3
Cruise: 12.5
Wot : 14.2

Shouldnt think look more like this:

Idle: 14.1
Cruise: 13.8
Wot: 12.5

 

I've had symptoms exactly like what you're describing in the past. Problem was a stuck needle in the secondary squirters. It was getting NO pump shot in the rear. Take the hat off and check it, its worth a try. Wideband graph looked similar to that on mine too when that happened.

Craig

 

Did some research on here and these are some thing's I'm going to look at:

Taking the hat off and operating the throttle to make sure the squirters are funtioning properly.
If more than .020" of the transfer slot is exposed at idle drill a hole in the primary blades 1/16" on their leading edge.
Play with idle mixture screws
Run bigger squirters

Question: Is it normal to have carbon build up on the spark plugs? Whenever I pull the plugs out they are black, it's just due to a rich idle right ?

 

I noticed when I was having a lean shot when I snap the throttle I also stepped up the squirters from 31 to 41 front and rear. Made no difference...went to a 51 front and still no change. I changed the 30cc to a 50cc in the front pump and that took care of it. Of course I am using E85 as an example. On 92 octane pump fuel the 30cc with the 31 squirter was perfect. You are scary lean man. You need to atleast up those rear jets and richen that thing up under WOT.

 

I have 69/85 in there now, I'll up them to 89 in the back.

 

My 950HP is one I sent to The Carb Shop also. I am trying to remember...when I was running pump gas I had 99 in the rear and I think 80 in the front. I tried to go smaller in the front but it didnt like it. The car ran great everywhere but it did make the plugs really really dark. Since I have switch to E85 the plugs look like new all the time. lol

Also...what have you done with your timing? Is it locked. I run mine locked at 34 and on pump fuel I pulled out 1.5 deg per lb of boost. Then it was 10lbs of boost.

 

I run mechanical advance set at 34 full timing, not pulling out any timing. Motor is 7.9.1 compression, Intercooled, 93 octane, 15# of boost.
Pull's great from a roll but a dog in low rpm/dead stop.

 

Maybe you do need to try larger squirters and try adding a 50cc accelerator pump in the front. It workd for me. Worth a shot.

You have any pics of your car? Would like to see a fellow Pontiac...Chevy engine...Procharger car.

 

Thanks, I'll give that a shot.

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Great looking car man. And my bad...I was going by your name and was thinking your car was the same as mine.

BTW...Where is your Blow off valve?

 

Thanks, it's next to the radiator... Big red race procharger one.

 

Oh I see it now in this pic. The same one I have. I just mounted mine right after the Procharger.

Ok sorry I jacked your thread. I just wanted to see pics.