Todd.

I do not know what maximum bar your different stages operate. I do know the Porsche ECU closes down the throttle body at 1.3 bar (even if it spikes). It took us a long time to remedy this. Has EVO been able to successfully address this in their ECU programing? Or have they just stayed below 1.3 bar?

 

We do not have a problem with the TB closing beyond 1.3 bar. Our Stage 4GT makes 1.4 bar in the midrange and after 4500 RPM's it holds at 1.2 bar untill redline. Without other internal upgrades, I did not feel 110% safe running the full 1.4 bar until redline.

 

Todd,

I may have this wrong, so feel free to set me straight.

My car use to show 1.7 bar on the boost gauge. The sensor for this stock gauge is located on the side before the throttle body. We placed another boost gauge after the throttle body. We learned that up to 1.3 bar the readings were equal on both sides of the throttle body. Once you hit 1.3 bar, the ECU would begin closing the throttle body. The measurements before the throttle body would read as high as 1.7 bar. The measurement after the throttle body would be 1.1 bar. In other words the ECU would close down the power when 1.3 bar was reached.

My question is, we're you able to handle this through changing the ECU to eliminate the throttle body shutdown?

 

1.7 bar??? Was that number in between shifts? You will get a spike in pressure before the throttle body if the throttle body rapidly closes during high boost. This is a normal occurrence in between shifts however, if the TB is closing due to a programming problem, you may see a spike as well. I am not sure about this because we never had that problem. When we were on the dyno @ GIAC tuning Stage 4GT we monitored the TB, knock sensors and A/F. The TB stayed at 100% and we had no knock activity and A/F peaked at 12.5.

 

No Todd, it is not between shifts. If the car is in fourth gear at 4000 rpm's and we go to WOT, we can attain 1.7 bar in an extremely short time. This is not on a dyno, but real road conditions. We monitor it with two Motec boost gauges. One before the throttle body, one after. This is the maximum boost attainable as it can be controlled with the adaptive boost controller.

The only reason I ask is I talked to one person with your Stage IV, not sure if it is the GT version and he is seeing 1.4-1.5 bar. If this is being seen on the stock boost gauge and the ECU code has not been modified, then the throttle body is closing to compensate. Also, I didn't say the throttle body shuts down completely. I said it shuts down to the point of only allowing 1.1 bar on the other side.

If the throttle body is staying wide open and you have not modified the ECU (regarding the code which closes the throttle body at 1.3 and above) then I have to assume you are not hitting 1.3 or above bar boost.

 

Our Stage 4 upgrade was not programmed for 1.4-1.5 bar. If he is hitting those boost levels then I will assume he has over adjusted his wastegates or has a problem with his boost control valve. The boost request for stage 4 is 1.2-1.3 bar only.

Our Stage 4GT is programmed for 1.4 bar and the throttle stays at 100% throughout the rev range. When we test and tune we monitor the TB angle as well as the boost with an external boost gauge.