Low Boost

[Dwightb]

I lost access to this car for the last couple of years. Now that its returned (from Ohio) to Colorado I note that the torque seems a little low. Yeah, it now has ~100K miles on it but one would think with all the ECU hooks that the OEM boost targets should still be met. The car is basically stock (aftermarket CAI & BOV). A Dashhawk log shows the boost ramping up on a WOT pull and leveling off ~11psi and the WGDC running ~28% from 3K - 5K rpm. The AFR looks normal; 14.6 until the RPM goes past 4k where the AFR drops down to ~11. By all appearances, the ECU looks to have achieved its target otherwise wouldn't the WGDC increase? I assume that altitude (I'm at 5000') doesn't affect the system targets.

[TiGraySpeed6]

OEM tune logic is load based, not boost based. In the most general of terms that means you may well not come anywhere close to what you're considering your boost target numbers and the ECU will still meet it's target criteria.

Elevation, seen here as barometric pressure, can reduce targets compared to sea level to protect the engine/turbo. Combine that with colder ambient temps and you can very easily be meeting the conservative OEM targets while seeing low boost pressure.

If you'd like to make changes you'd need an AccessPort or VersaTuner and I'd suggest looking up one of the several great tuners that can provide you with an "E-Tune" where you trade logs and map revisions by email. Best bang for the buck you can get and your car will run as well as it safely can.

[Dwightb]

Thanks TiGray;
Load based, understood. So what variables does the ECU use to determine "load" and what are the the OEM load targets.

[SarcasticOne]

Originally Posted by Dwightb Thanks TiGray; Load based, understood. So what variables does the ECU use to determine "load" and what are the the OEM load targets.

Load = MAF airflow * 40 / RPM