i had a homemade (home depot) boost control i was using to set my 5 psi waste gate to 8-9ish. but lately its been only boosting to about 4-5 at full throttle. so i took off the boost control today just to test and bam . i get a full 8 psi on the dot steady boost every time. i guess when i cut and re welded my wastegate it just happened to modify it to 8 psi so i guess that boost control was killing me that whole time.. now i got so much more speed.

Thats odd. A boost controller can't cause the boost to be less than the wastegate setting. Only greater than.

Originally posted by CarbonFiberRST
Thats odd. A boost controller can't cause the boost to be less than the wastegate setting. Only greater than.

it can if its homemade and done incorrectly :)

it worked for a few months well but i guess the spring inside it wasnt made to handle heat so it was failing causing low boost at full throttle. oh well . its way better now.

I wonder if that is what my turbo's problem is. When its really hot my car will do the same thing yours does at WOT. But when its cooler it boosts pretty steady. I have the profec B spec 2 hooked up, but I am not sure its all the profecs fault. This whole thing has me baffled. I'm glad you are getting steady boost though...must feel nice...I have not had the pleasure of feeling what a steady boost feels like. Mine flux's up and down like crazy!

Originally posted by mcgyvr

Originally posted by CarbonFiberRST Thats odd. A boost controller can't cause the boost to be less than the wastegate setting. Only greater than.

it can if its homemade and done incorrectly :)

I guess it could be trapping pressure and holding the gate open...

well anytime i could boost like half throttle and get a full 8 psi , but anytime i was WOT it would go to like 4-5 and not climb . it was the boost controller for me , now its fine.

thats what happens with mine. At about half throttle it will be full boost, but the full boost at half throttle doesn't even feel that its really pulling that hard. And if I give it full WOT then it jumps down and holds steady at about 4.5psi.

try a new boost controller . it should help .

Originally posted by Aggression
thats what happens with mine. At about half throttle it will be full boost, but the full boost at half throttle doesn't even feel that its really pulling that hard. And if I give it full WOT then it jumps down and holds steady at about 4.5psi.

You need to adjust your settings then, the profec b needs to be tuned.

Look on page 49 in the user manual. There is a trouble shooting table. It might help


Boost falls off. Cause = Gain is set too low Increase Gain