ECU Boost Control Question

[Slade-Runner]

After installing my downpipe and flashing Cobb Stage 2 OTS map on my 08 Spec B, I noticed it overboosting, I reflashed to low wastegate tune and still was getting some overboost. I was talking with a couple tuners and getting different opinions, varying from needing an external wastegate to the downpipe divider obstructing the internal wastegate. Then I noticed that it was peaking a little over 15psi (Cobb's notes were saying peak should be 16psi +/- .8) and stopped overboosting after about a month of driving. The tuners I talked to said before this that the ECU's learning doesn't affect the boost control and wouldn't be the cause of overboosting. I tried resetting the learning, and it overboosts again. So did the tuners misunderstand how it works or is there another potential issue?

 

I also did a smoke test to check if I have leaks anywhere and found smoke coming out from the plates opposite of the TGV motors on booth housings, is that normal or could there be a bad seal?

 

Stock/Mod list:

Stock intake, stock boost control valve, stock bypass valve, Invidia turbo back (lower cat), Grimmspeed TMIC, Perrin turbo inlet hose

Edited May 20, 2021 by Slade-Runner

[xt2005bonbon]

What was the ambient temperature? Elevation is essentially sea level for you?

[Slade-Runner]

What was the ambient temperature? Elevation is essentially sea level for you?

 

Ambient temp has been all over 50-70, raining some times when cold and dry when hot (Seattle area...), sea level.

[xt2005bonbon]

OK.

 

 

Exactly how much overboosting have you noticed?

[Slade-Runner]

OK.

 

 

Exactly how much overboosting have you noticed?

 

When I had first been running the low wastegate tune, 17-18psi and sometimes 20psi spikes when target is 16psi +/-.8. Now after the reset it spiked upwards of 17psi, but after a few days it hangs around low 15psi sometimes spikes to 16psi. today it maxed out at 13.9psi. Could the wastegate actuator be going bad?

[Slade-Runner]

bump?