Hey guys, just had a weird happening. Just noticed that I've gained about 3-4lbs of boost. And didn't notice this until after I put on the custom straight thru exhaust. Exhaust, intercooler piping and air intake are all the upgrades I've done, no GMS1 kit or tune has been done yet. Is my boost gauge reading incorrectly or could improving the exhaust flow have improved boost pressure? Anyone ever ran into this?

 

in the SC cobalt, it would actually go down.

 

It's an '08 SS/TC

 

The boost pressure can fluctuate quite a bit. The car's goal is to make 260hp 260tq and it changes the boost as needed to achieve that.

 

I can see that, but the learn down is still attached to the PCM so it shouldn't be going above 15 psi should it?

 

Boost pressure does not matter to the computer, it makes a set amount of power. It changes the boost pressure to meet the required power level. There is no set boost level.

 

makes sense, appreciate it. Still new to the turbo/tuner scene.

 

No prob, that's what we're here for.

 

Factory LNF tune is 14-20 psi to meet 260tq. Not HP. You will see in dyno's that the HP is 230-259.

 

Mods that improve cooling and airflow Inherently reduce boost pressure. Better flow means more efficient power which equals less boost. Since the engine is aiming for a desired power/ air load the ecu should actually reduce boost a bit.
Increased boost could be a symptom of hot humid weather or a change in air pressure or altitude.

 

When I upgraded from Stock exhaust to ZZP Long Tube Header/ Catted Downpipe, my boost went down, but my HP went up.