Today I've installed a midpipe in my FD. I'm also running a Pettit Racing Unlimited ECU, intake, downpipe, catback and IC. As soon as I've installed it I've gone for a ride in order to tune up my greddy profec B for my new setup.
My boost controller works great, and I had two setups, for 10 and 12 psi. But now, with full exhaust, everything has changed. It doesn't matters how I tune the profec B, with some different settings I've experienced always the same result: The more I rev the car at full throttle, the more the turbo blows. I have hitted 15 psi at around 7K rpm, and I have tried with tons of different settings. The response is different when I play with the profec, but the problem is always there, my car doesn't stop to blow, higher and higher.
Is this what you call "boost creep"?? I've a track day on sunday at Montmelo international circuit, and I wanted to run full exhaust but I think I won't be able to if I don't solve this problem...

 

ya that is boost creep. you are running the twins still right? I get it with the same exhuast mods in the winter time, because the colder air temps. In the summer i never see any creep, you are going have to port your turbos to make it go away. They also had a plate you could put in ur exhuast to cause more back pressure but thats just a bandaid fix.

 

Yup. Good ole boost creep. You need to pull the turbos and port the wastgate hole or use a restricter in the exhaust. Do a search on "Port Wastegate". G

 

never port your wastegate with one of those electric dremels i was at it for hours...

 

Yep. Boost creep. I have never been able to control boost in cold weather on any of the 4 turbo rotaries that I've owned over the years when I had an open exhaust. Best thing that worked for me was to introduce a restriction into the exhaust to allow just enough restriction so that a boost controller could keep things in control.

The latest thing that worked for me was to add a metal cat to the mid pipe I was running. See pic

 

 

Yeah, that's what I thought. I won't be able to get any restrictor plate for sunday, and I won't port my wastegate cos I don't want this "loud" setup forever I will put my hi-flow cat again and run with it... Thanks for the info

 

Yep, I agree with everybody. Mine had it bad, sometimes making the needle spike to 20psi. It was faster and smoother with the high flow cat I originally had.

 

Have you removed the boost restrictor pills from the wastegate lines? That will solve the issue in a lot of cases. It isnt a definate fix for your problem but it will make the boost managable in most cases.

 

No, I have not done that. In fact I had no idea about these pills. I'll try it next time I want to run full exhaust.

 

wow..you have a profec b installed and still have the pill in the wastgate line?? the pill is what gives you the 10psi with the stock setup...

take the pill out of the line going to your profec b, not the pre-spool hose(leave that alone). take the pill out and plug the hose back in to your greddy box. now redo your boost controller settings(put balance and low-high boost back to 0). with the boost controller off you should be pulling 7psi with all settings low. this is just to make sure its working correctly. now tune your profec b for the boost level you need.

this is for the profec b boost controller only, not the spec II

 

Mmmmmmmm, I really don't know where are these pills located. The only thing I can tell you is that my profec B works great with the hi-flow cat running. As you say, with all settings low I'm running 7 psi, and I can see how it pulls stronger as I set the "set" up, so I suppose that it's already working as it should do...
This is the installation I did when I installed my boost controller:

 

Sorry man, I didn't notice this! I'm running an spec II!