Hi guys, I've got my driveability tuning pretty much nailed down. The car is an 02 camaro and the Mods are 230/232 f13 cam 114 lsa FAST 102/92, the usual bolts ons and a 33lb clutch. I've pretty it pretty well sorted now with the fast combo. Idle is in check, car no longer stalls when pushing the clutch in rolling and RAF is ok. In order to stop the car from stalling with the clutch in while cruising I had to add TC back into the original tune since it was taken out as well as utilize the rolling airflow tables. The TC does not zero immediatley with the clutch in but the follower seems to do it almost instantly.

The last issue I'm tackling and it seems like a horrible catch 22 is idle under hard braking with the clutch out. If i'm rolling (no throttle) through a parking lot at say 10-15 mph, 1000-1100 rpm with the clutch out in nuetral and I have to slam on the brakes the car will overshoot its 825 commanded idle and will usually stall. I though of trying to slow the follower decay but since my foot is off the pedal when this occurs I dont know if it would really help.

In my tune the 1000 rpm TC column is largely around .5 g/sec. If I go ahead and raise it to 1 g/sec it helps the issue a lot but the problem is then I run into bucking at light throttle in parking lots and take off becomes jerky if that makes sense? Is .5 g/sec more even enough to cause that or could it just be in my head? I thought about adding more air to the rolling airflow tables but to my knowledge thats only active on clutch in correct?

If theres anything someone could suggest where I go from here it would be much appreciated. I dont have a current log of what the condition with my tune, but I can get one if you all want to see it. Just at work now so I figured if someone had a suggestion I would try it driving home.

Thanks Dan

 

I found that after I had finished tuning my VE & MAF that I had to re-check my Idle Airflow table. I ended up needing a bit more air than the initial RAF process indicated... 5 more grams from 68-140, 2 more grams from 176-230. My last tuner set my TC enable to 45 and disable to 43 and left the TC Airflow table as received.

For the bucking, note at which g/cyl vs RPM it's occurring in your log and try adding or removing timing in that cell and smooth the surrounding cells. It will take some time to dial it in, best to have someone adding timing using VCM controls from the passenger seat while you're trying to duplicate the issue. You can also try raising the airflow in the VE table a little bit at a time in the affected cells and see if that helps.

 

I got a log of whats happening... I tried adding 3 degrees of timing to the idle spark tables and that just made it worse. Then I tried adding .5 g to the raf and that gt me no where either. I can see the TC is active via the histogram when the condition occurs but I'm not sure if i should try adding more air there? This is pulling into parking spaces it seems cutting the wheel to turn in causes the ps pump to put a big load on the engine and makes it stall