i have a 06 sti and i was getting on the freeway the other night and i was taking it up to 7 before shifting and i believe at about 6000 RPMs i got boost creep leading to fuel cut and all my ligths started flashing... if im correct could u tell me more and if im not correct can u tell me what it is and how to fix it? thank you

 

Any mods?

 

Check out this article on boost control: http://www.sportcompactcarweb.com/te..._boostcontrol/

The stock turbo shouldn't creep. If you've modded the car this can sometimes happen. You may be able to port and polish the wastgate to eliminate this.

 

I also have an 06' STI that is stock and had two instances within 5 minutes of each other where shifting around 6800-7000 had fuel shut off. Car had about 3000 miles on it. It was also about 70 degrees. Weird? Guess I need to get a boost gauge to see what is going on.

 

Thats weird I have a 06 STI and just the other night i was doing the same and i had fuel shut off. It happened twice within like 3 minutes and i have not modded the car at all the car has 1700 miles on it.

 

that's wierd man, I hope I don't run into that problem

 

maybe the 06 have a boost proble... my car only has the APS 3.5 turbo back right now everything else is being put on this saturday, but thnx for everything im going to keep researching

 

Anyone find out any more info on this?? ive got a TBE in the mail and im having second thought about putting it on because of this issue..... is this happening to all 06's or just you guys with the STI's??

 

ok well if u don tknow i have quite a few mods on my car, most form APS... one of the items is element tunings HYDRA standalone, once i got this it became worse and by 3500 in 4th gear i would hit fuel cut... i decided to let garrett at world one performance know and he came to my house from seattle and lowerd my boost around a pound and a half and made my boost curve alot straighter. this helped tremendously!!! Garrett told me that with the sti's they come with a small by pass valve on the turbo and when the boost builds up not all the air can escape to keep a steady boost causing to much boost making boost creep that gives u fuel cut. so if u want to fix it u can eather do some sort of boost control, have ur bypass valve on ur turbo inlarged, or get a larger turbo even such as a fp green would mkae a large differance. if u have any questions i will try and talk to him again.

 

Yeah i installed my TBE last night and sure enough the first run out i hit fuel cut in 4th gear.... looks like im due for a bigger turbo already

 

i have the same thing going on with my 05 sti and was told to do sme porting on either my wastegate or turbo, i cant remember...but im upgrading so i didnt bother

it didnt happen to me until i did my 3 in tbe with a really crapy bellmouth.

 

yeah porting or a new turbo will help and its normally only a problem in 4th or higher

 

boosting creeping to around 20 psi on my vf34 in my 04 wrx. it was tuned for 17.5 psi by mike @ gruppe-s .. i have added borla headers, perrin inlet hose and shortram, so that's why it's been creeping. I've been running with the boost creep for a good 8 months now, it's not safe but i can say that i have taken it flat out before shifting at redline in all gears and nothing happened. I'm taking it slow now since im due for a retune in aprail with bigger tmic and turbo wastegate port

 

STis and boost creep with the factory turbo and a turbo-back exhaust system on an otherwise stock STi.

I would like to explain what we have seen with the factory boost control settings on the stock STis (2004-2005). The OEM ECU raises the Wastegate Duty Cycle (WGDC) % approximately 40% as RPM increases from 2400 to 5600 RPM. They do this in an effort to compensate for the restrictive exhaust system found on the stock vehicle. They are trying to maintain a level boost pressure at higher RPM while running with the restrictive stock exhaust system. If a less restrictive exhaust system is installed on the vehicle, then the increasing WGDC will make boost rise as RPM rises.

This does not mean that mechanical boost creep does not exist, or that a proper wastegate porting job is not possible. I am just trying to point out that if you install a turbo-back exhaust system that flows well on an otherwise stock STi you will most like see boost creep through your boost gauge. Although, this perceived boost creep is due to electronic manipulation of the mechanical wastegate using an efficient turbo-back exhaust system, not due to the wastegate on the stock turbo being too small.

I would highly recommend you verify that you have mechanical boost creep before you port your wastegate. My experience has been that you only introduce problems when you port wastegates.

Think about it this way; a wastegate's function is to re-direct exhaust energy past the turbine wheel into the downpipe so that the turbo shaft speed decreases or remains constant. With porting a wastegate, you are trying and make that function potentially work better which means that your turbo is going to lower boost super fast when the wastegate door/valve opens or not run as much boost as it was engineered to.

The MORE boost you run the LESS wastegate you need/use. So unless you want to run less boost than stock and/or have un-tunable boost problems, then I would leave your wastegate, the area around it, the turbine housing, etc. alone. If you make your wastegate react quicker then boost will be very difficult to stabilize and reach peak #s at an earlier RPM. If you make the wastegate flow better, then the exhaust energy your turbo needs to make and maintain boost will have less opportunity to flow across the turbine wheel. Generally speaking, air/pressure/exhaust gases will always flow along the path of least resistance. Not bashing, just trying to give you a different perspective.

Take care,
Christian.

 

so if boost creep occurs with an aftermarket or even the stock sti exhaust? would tuning fix this by itself? or the addition of a boost controller along with exhaust and tuning? I'm getting ready to add some mods to my 06 and dont what this problem to occur.