I just installed Apexi dp and N1 cat back last weekend and now my boost gage reached a peak of 22psi compare to 20psi previously. My car is all stock except the exhaust.
Has anyone pick up boost after install aftermarket exhaust system?
I am sure this indicate power gain as I can feel it pulls stronger.

 

Yea, i had that happen to me when got a dp and catback. Its nothing to worry about but if it bugs u too much, a tune and/or test pipe will help.

 

This is actually very normal.

By freeing up the Exhaust it raises the boost. Should not cause any problems but I would recommend engine management as your next step.

Ben

 

When I installed my cat delete to the remaining stock exhaust I gained 2psi as well. But just from going catless.

 

i will hit higher boost peak, that is normal

 

Same here when I put a full 3" exhaust system , the boost jumped for another 2-3 psi

 

i got mine tuned for 20.5 psi, should i tune it down back to 20.5 cause it hit like 22 or 23?

 

22 psi is 22psi, If boost goes up from weather, mods, anything, you still have to turn it down to your car's safe boost level where detonation is under control.

Dont worry the net gain from the mod that increased the boost likely out weighs the loss of tuning down the boost.

In your case the increase of boost is caused by an increase in efficiency. The turbo does'nt have to work as hard to achieve 20.5 psi now. You probably have less boost taper up top in first gear.

When I replaced my stock BOV with an Forge rs, I had to turn the Hallman down one whole turn. The car isn't much faster but I have much less taper in boost and the car is tad bit more efficient