Hesitation when under acceleration

[InzaneSR20]

Ok about 5months ago i had a stage three spec clutch installed to replace the stage 1 exedy clutch.It was done at a local performance shop. At the same time the stock flywheel was shaved. Now when I down shift from 5th to 4th or 4th to 3rd and the rpms are up around 3000-3500rpms and i stomp on it the car will start to take off fine but all of a sudden bam, it hesitates/ bucks, it almost seems like full cut but it's not, I havent touched the boost levels on my car since I bought it back in June. Low boost is at 10lbs. and high boost is set at 13-15lbs. I also have left the sharpness on the boost controller the same, clear down at mild. Another thing is that it wont do it if i go from a stop light and go up through the gears. Can anyone suggest what the problem might be?? I told this to one of my friends and he's been in the car when it's happened and he suggested maybe it was the stock flywheel. Could that be it? Does anyone know?

[tazjig]

Im not exactly sure of the problem but i highly doubt its your flywheel, if it was you would feel it more often, also i had the same thing done to my flywheel when i installed my stage 1 exedy and its been fine.

[knave]

Sounds to me like you're getting knock and the ECU is pulling timing. You'll feel a sharp decrease in acceleration, followed by a gradual ramping up of power again while it tries to find the optimal timing. Maybe you're running too much boost for the weather or you're getting a lean condition somehow.

[InzaneSR20]

Right now I have the Greddy Profec B boost controller and greddy emanage with a Apexi Turbo Timer and I have a AC Autotechnic Boost Gauge.

That's what it seems like because when i downshift and i have the pedal the whole way down, the car goes, but then it was almost like a buck and then it picked back up and then did it again, now if i dont have the throttle down the whole way it wont do it.

The A/F on the turbo timer reads 20.0 and the light is green when i'm not on the gas or at idle, but if i'm on the gas it will drop down to around 10.5-13.7ish in around there under full load and the light turns red.

[Nismo_Freak]

If you run 10 PSI does the car still hesitate?

[InzaneSR20]

I just checked it today on low boost, I set the low boost knob to 10lbs and checked the gauge and it worked fine. I just have to do high boost now. So do you think it's just pushing to much since now the air is alot colder?

[Nismo_Freak]

I just checked it today on low boost, I set the low boost knob to 10lbs and checked the gauge and it worked fine. I just have to do high boost now. So do you think it's just pushing to much since now the air is alot colder?

Check your plugs see what they look like and in the process, get new plugs. Try closing the gap a little if you get the same hesitation.

[InzaneSR20]

alright i'll check them tomorrow and tell you what they look like, better yet i'll put in a pick.

[InzaneSR20]

If i get new spark plugs, what do you suggest?

The shop near me suggested Autolite ones the copper end ones?

[SR20DETPoweredS14]

Spark Plugs I would suggest would be NGK spark plugs with a heat range of 6 or 7.
Modified by SR20DETPoweredS14 at 12:13 PM 1/20/2005