I tested the changes this morning and they do work. On a cold engine I could only boost about 14~15 psi (about wastegate pressure) and after the engine warmed up I boosted the default 22 psi my car is set for. This is using a GM 3 Port and 30% as the Cold WGDC value. So bye bye to cold engine boost overshoots.

Many thanks to tephra for the address in my ROM and razorlab for the tip on the table. I will update the first post to described the changes I made to ECUFlash.

 

yeah but thats the wgdc vs coolant temp table at work.

 

He was overboosting when cold before though.

 

hrmm...

dunno then

 

Apparently since the WGDC vs Coolant Temp table is not available in ROM ID 96420008 what that ROM uses is a straight value for Max WGDC when cold (Temp < some setpoint in the ECU); and according to razorlab when there is a CEL on the car. I have tested the temp part but not the CEL part.

What I was most interested is to be at wastegate pressure while the car heats up to normal temp. Is not that I race the engine when cold but just a nice preventive thing to have in the Boost Control. Before this change I had overshoot over 25 psi about 2 times on a cold engine. in like 6 months. It will happen very fast in first gear even if you are not at WOT. I believe a mid throttle will do it. Anyway its fix now.

Another great reason to use ECU Boost Control vs a MBC (at least for me).

 

I gave you the addresses for WGDC/Coolant temp b4 - its available...

 

OK Im confused now.

What you are saying is that the Max WGDC vs Coolant Temp is:

- 0x61d6 for the table and 0x69e6 for the coolant axis

Then the Max WGDC Cold Engine \ CEL is:

- 0x2200

Is that correct? Then whats the difference between the two, specifically on the Cold Engine / Coolant Temp part. They seem to be the same but with less control on the second one.