Because of the post below. I dont think its boost creep. If it were boost creep, the boost level wouldn't stop at 11.6 psi. It would continue to rise. It sounds like secondary boost goes to 11.6 psi, and holds there until fuel cut at 6500 rpm. To me, this is classic overboosting, which is normally caused by removing restrictions in airflow. Remove even more restrictions, and you will eventually get boost creep.

 

Pardon? You're improperly defining boost creep, plain and simple. Wether or not thats this persons issue is beside the point, maybe you should learn to a bit more polite?

 

I dont consider it to be polite to state that I am wrong "plain and simple" .... "period". If you expect a polite response, don't act arrogant and dismissive.

Boost creep is when boost starts to rise, and continues to rise out of control. Overboosting is when boost levels go above where you want them, and then level off at that higher level.

Overboosting example : You would like your car to boost at 10 psi. It overboosts to 12 psi, and holds there.

These definitions are commonplace on this forum. They are accepted by many rotary specific mechanics that post here frequently.

 

You know what, nevermind. Have a good day.

 

I believe boost creep can refer to whenever you have any boost over the pressure at which the wastegate is fully open.

This could be a stablized boost such as the factory stock S4 turbo boosting 6psi on stock 5psi wastegate.

It could also be runaway boost creep where the boost continues to rise with rpm.

I have had both on my FC through various permutations of exhaust and turbos.

With that said, enlarging the orifice size on the restrictor may be able to lower boost. Putting manual boost controllers lowered the boost for me on the 2ndary turbo when I had the same symptoms.

It must be that the stock solenoid doesn't go to 0 duty cycle on the stock open loop boost map.

Reducing the restrictor decreases the affect of the solenoid bleeding boost off the actuator. For example we know when you take the restrictor pills out of 91-98 spec turbos it runs 7psi despite the solenoids keeping their same duty cycle as the stock 10psi boost pattern.

 

I still believe my problem isn't boost creep after installing an exhaust that was fine on my other FD. On the 99spec engine the boost was increased to get 280HP therefor the restrictions that are now built into the turbo allow more boost so I will have to drill that out and put a boost controller and hopefully that will fix the problem..

 

Yes, I agree drilling out the nipples should lower your boost and a manual boost controller is the easiest way to get it back up to 10psi.

Good luck!