Ill try to make this short.

the past 48Hours i have been stressing because of boost creep.

i installed a Test pipe on my car 2 weeks ago. this caused the boost on my car to go up 1PSI which in return caused fuel cut out at the top of 3rd.
I orderd a fuel pump and it didnt fix the problem so i got a AEM true boost controler. now i installed them both and i was experienceing boost creep only at the upper RPM range.

Even if i set the car at 12 PSI it would hold 12 till 5800RPM then shoot to 21 at redline.
I talked to AEM none of us could figure out the problem i messed with the duty cycle and spring pressure nothing got it to work.

So tonight i thought i would back track. i took off the Test pipe and put the Cat back on.
Bam the problem was fixed. now even if i set the boost as low as 12PSI it will hold it untill redline no problem.

Does this make any sence to any one?!?!? not to me!!! tons of people are running the exhaust setup i have with a test pipe and 02 without boost creep. IDK why the test pipe gave me boost creep but it did!
any one else have this problem?

i have a 3inch TBE with a megan 02 housing.

PS some people said the 02 housing would make the boost creep but it didnt on my car because it worked fine before the test pipe install and now after i took it out.

 

Did you get a tune?

 

nope i didnt tune it at all. I have been waiting till i did all the mods then im driving to AMS which now should be in a week or 2

 

damn ams is gonna serve ur *** good on a tune price. they tuned out here in vegas for $500 and people were knocking left and right and had to pay another $200 for a fix.

 

The O2 housing could still be one possible cause of your boost creep. If the merge opening between the two O2 housing chambers is too small it can restrict turbine housing bypass flow. There are a couple of threads with photos that address this issue and outline the remedy via judicious grinding of the opening. You'd have to search for it though.

Another possible resolve would be to port the turbine housing's wastegate bypass port(aka WG hole). To undertake this you'd have to yank the turbine housing of course. PM me for details if you want to try this method.

Before trying either of the above methods, which both invove considerable wrenching and grinding, you may want to have a go at adjusting your turbo's WG preload via turning the adjustable, threaded, actuator rod.

If as you have stated, you can adjust boost all the way down to 12#, then the actuator rod is too long and needs to be shortened. You'll have better control of boost up top if you set preload to about 17# when your target boost is 18+ PSI. Are you using the stock WGA? If so, the Forge unit is better at controlling boost once you have done all the exhaust mods as you have on your car.

Also, you may want to try swapping in a known brand of MBC, such as a Hallman or Forge unit, just for comparison's sake. These two straightforward and basic MBC's are proven to work on Evos.

Edit: You should Log your car and have it retuned to compensate for your exhaust mods. AFR's are probably way lean.

 

Whoa there, whose car are you talking about? I would never charge someone to retune thier car if there was a significant issue with it.

The only 2 re-tunes from an AMS tune this weekend were for upgrades. One was an upgrade from a 91 oct to 100oct map, and the other was a cam swap adjustment.

I did re-tune a car which was previously tuned by someone else, much to the driver's delight. I remember him commenting on how much smoother and faster it was...

Please provide additional details and feel free to email or PM me. Also, tell your buddy to contact me directly if he has any questions about his tune...

Thanks

 

I did a little Research about boost creep.

Seems that the cause of boost creep is from an exhaust system that is to free flowing. which before now i have never heard of such a thing! so the cause of the boost creep could be any piece of my exhaust it just happend to be the test pipe that put it over the edge lucky for me i replaced just the test pipe which would be alot easyer then pulling my turbo and putting the stock O2 back on.

1 3inch TBE
2 ported stock manifold
3 Megan O2
4 3inch Test pipe

any of these things could cause boost creep. if used all 4 togeather. but you can also mix and match any 3 of them and not have boost creep. unfortunatly for me i didnt know you could open the exhaust up to much if i would have known that i wouldnt have purchased all 4!

Maybe AMS can help me tune my car and adjust the WGA so that i can use all 4 but for now i took the test pipe off and its running good.

maybe i can use the test pipe again but i dought it. i think i need External WG, new WGA, or like some one said port the WG hole.

 

I am sure we can figure out the issue and solve it for you at AMS. I have never experienced the problem that you are having first hand. Usually, the problem is quite the oppostie, where boost will fall off in the higher RPM ranges. I am sure that once we are running adequate timing, the boost will drop as well.

As long as there is not a wastegate flow issue up top, I will be able to tune it without making any physical adjustments to the boost control setup of the car.