The car is a 2.5L wrx with a cat-less 3inch turbo back exhaust and an intake.

We put the cobb stage 2 reflash on the car with the accessport and the car would only peak 13psi and fall off to 9 psi.

Last night we unplugged the stock boost control solenoid, and hooked up a Hallman manual boost controller. No matter how much we turn the boost controller up, the car will peak at 15-16psi, and fall off to 10-11psi.

We put a wideband on the car and its hitting a high of 10.3:1 and falling off to 9.9:1 and maybe lower, im not sure if the innovative even reads that low. These wideband numbers were pulled with the boost controller turned all the way up. (15-16psi falling off to 11-10psi)

The owner put an aftermarket blow off valve on the car and sold his stock one, then later got rid of the aftermarket BOV to a person with a 2002 wrx and put the stock 2002 bov on the car. and thats what it has now.

My question is...do the stock 2002 BOV's on these cars leak badly? Could our reason for not being able to up the boost be that the bov is leaking all the boost out? Or is there some other reason, like some sort of electrical/ecu crap that is limiting it.

remember the stock boost control solenoid is no longer connected to the wastegate. and we did a boost leak check that showed no leaks.

All boost figures were read directly off the accessport display

I could try to shorten the wastegate arm or some other solutions but it seems like those are just bandaids to a problem i want to fix the correct way.

 

following up on this...

we were doing all our testing pulls in 3rd gear. It looks like with the boost controller cranked all the way up, the boost acts like this...

1st gear: 12psi peak falling to 8ish
2nd gear: 13psi peak falling to 9psi
3rd gear: 16psi falling to 10psi
4th gear: 18psi peak falling to 12ish psi

rolling into 4th gear will spike a pretty large spike of boost, and hit fuel cut. so the boost went back down to where it was spiking 16psi in 4th.

Is there an obvious reason that im overlooking as to why this is happening? or is this just how terrible the stock turbo is?

The boost controller is hooked up from the compressor cover nipple of the turbo, to the wastegate, should i take the boost source from somewhere in the intake manifold maybe? to get a more consistant pressure signal?