I had the Stillen 9lb pulley + Vortech Impeller + PPI Long Tube Headers and made 11.9 lbs of boost.
Dyno'd @ 483rwhp and 378tq ... but it wasn't running quite right.
Blew the motor 1st time down the 1/4 mile when I lifted past the traps [12.3 @116.9]

Yeah its hard to believe that you would lose that much pressure from just the headers. No way. Is your BOV possibly letting some pressure out when it shouldn't? Obviously you didn't go to redline and would prob gain a pound or two more from 6500 rpm.

I would think that if the increased flow from performance headers were causing your drop in boost, you would still be seeing pretty high numbers on the dyno even with the psi down. Just thinking out loud.. I am not an expert.

I have Stillen headers, high flow cats and catback exhaust and achieved 380 whp with just under 8 psi boost and a completely stock Stillen SC setup/kit , but with Uprev custom tune.

We feel the same way. I still have the Stillen 9lb pulley to add more boost if needed but I still feel something isn't right on the car.

Somethings not right, is your belt slipping?

it has to be really tight on this setup, like REALLY tight.

I think the same :iagree:

Too manyy Twists and Turns in the piping can also steal boost pressure.

This is true, but My Air to Air has more piping and more bends.

I made 7.7 psi at 5100rpm. Stock impeller with a 2.75" on blower pulley.

I don't think the piping/routing is the problem.

The tune so far has only been F/A adjustments, some time today the tuner is going to send us a flash with some timing advance do see what it does.

Is Harry tuning your car?

No, I really like Harry but I wanted the traction control options ecutek has and he only does UpRev.


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The timing won't gain psi. There's something else. If it were me there I would 100% no doubt put the Bosch bpv on and throw down a pull. That new spring could easily be a problem.

The one off the stillen kit?

Where did you go fior ecu tek