SSLogan

Hello, the car is a 2000 Camaro SS with a basically stock ls1 and t76 turbonetics turbo making 8 psi. It is currently set up with a MAF sensor (not SD) unlike a lot of turbo cars. The issue I have is that when you are at part throttle, and let the rpms climb, it starts to stutter/buck at about 3200-3400 rpm. To explain, it jerks back and forth rapidly, almost as if it were on a two step rev limiter while moving. At WOT, it seems to run perfectly fine, and pull hard. I'm newbie when it comes to tuning, but was thinking maybe I need to switch to speed density? Any info would be appreciated. Thanks, Logan.

kingtal0n

iTrader: (1)

Here are some common causes:

1. your bypass might be opening, when using a MAF sensor this leads to erratic operation. This theory is reinforced by the fact it runs fine at WOT (bypass is 100% shut) while at part throttle the bypass might be open.

2. How is the engine tuned

3. where is the maf sensor? and where is the turbo? I need to see all the plumbing to make an accurate diagnosis.

4. maf sensors require continuity. IF the turbocharger stalls (surges) at low-throttle, low rpm ranges it will whip the air at the maf hot-wire back and forth, you will see it on your data-logs as a maf voltage rapidly fluctuating. This is another common cause for issues when using a maf sensor with a turbo. The fix is to run a recirculated bypass valve that hangs open at idle and low-speed situations to prevent surge from influencing the maf hot-wire. If you are experiencing a slight surge as you tip into boost that is a different issue- the fix there is a smaller turbocharger or larger back housing. I doubt that is your problem (I had seen this only once on a 2.6L engine with the same size turbo)

The jerking around definetely sounds like a fuel related issue and because you have a maf and atmospheric bypass I am strongly suggesting it is your plumbing/design/maf related.