Turbo Boost Creep Creeping T25 14B 16G [Merged]

[RRF900RR]

All boost creep-related questions will now be merged into this thread as I'm seeing about 5 new threads a week on the same topic. The causes haven't changed, nor have the remedies- either port your turbine housing, add some exhaust restriction, or do the supporting mods that allow you to run more boost and live with the problem.

I've got a question about boost creep. What does it feel like? My car will start to cut out when I am accelerating hard when the rpms hit 4,000 or more. The problem seems to get more pronounced the higher the rpms get. This problem started after I installed my xbc boost controler. I have installed alot of bolt on parts in the last month so I don't know which one of the parts could be attributing to the problem any help that can be given would be much appreciated. Thanks

 

[IPT]

Watch your Aftermarket boost gauge. It should go to the level you have it set to then the boost will slowly rise. That is boost creep.

 

[RRF900RR]

thank you. I guess what is happening is not boost creep then. I guess I am going to have to break down and put the old beast in the shop to figure this thing out. Thanks for the help.

 

[Blixx]

boost creep doenst = fuel cut. Fuel cut feels like a brick wall and (mine atleast) flashes the CEL once quickly. You could be experiencing MAF overrun from the bolt-ons and higher boost level.

Blake

 

[IPT]

When was the last time you changed you spark plugs or wires?? With the mods you have been doing it puts higher stress on your ignition and a break up in the higher rpms can occur.

 

[RRF900RR]

The spark plugs and wires were done about 20,000 miles ago, but I did just go with the factory set up. I did not have any mods done at the time and was not planning on upgrades. I just heard on another thread that someone was having a similar problem. It turned out that he needed new wires. I am going to go out this weekend and pick up a new set to try it out. I figure that it is cheaper to buy a new set of wires than to let a tech figure it out. It can't hurt. Thank you for all of yall's help. woops there goes the Texan in me.

 

[IPT]

Get the plugs too. The are only $8 for a new set. (NGK's) Throw and ohm meter on the wires if the resistance is REALLY high the wire is bad. I replace the plugs in my car every couple of oil changes. I pull them out and check to see if I am running lean or rich alot!!

 

[RRF900RR]

On my way. I can't believe that I have been searching for this prblem for about a couple of weeks, putting different hoses, tightening everything down, and adding octane grade to the gas to try and get this problem to go away. I appreciate the help and I will post back after I do the repair and let you know if it took care of the problem. Thanks again for the help.

 

[Turbocyde]

what causes boost creep?

 

[allwheelTSI]

Originally posted by Turbocyde
what causes boost creep?

boost creep is caused by either a leaky internal wastegate or when the internal wastegate can't handle the pressure you're running. an external wastegate eliminates boost creep.

 

[awdgsx90]

Here are my mods: 3"cat back, 3"down pipe, stock turbo. I set the boost to 15 psi and before I installed the 3"DP I never got boost creep w/original DP. Now I getting insane boost creep. I have allready bought a 98 GS-T exhaust manifold. What do I need to do to get rid of the boost creep? I have heard if I port the 2G exh. man. and install a 40mm external wategate on the #1 runner that should get rid of the boost creep. is that person right or wrong?

 

[doug]

You need to open up the exhaust path directly after the turbo wastegate to get rid of boost creep. Creep is caused by not giving the exhaust gases a big enough "incentive" to exit via the wastegate instead of still going through the turbine housing when the wastegate flapper opens.

Port your O2 housing or buy one that is already ported or at least bigger, such as the EVOIII housing. Or get an O2 eliminator downpipe (but that's a chunk of change). See the parts guide under O2 sensor housings.

But yeah, a 40mm external would work too. But that's an even bigger chunk of change.

 

[Rob]

O2 dump = No Creep ......kick ass Exhaust sound

 

[awdgsx90]

Thank guys for the info. I think I will port my 2g exh. man. and o2 sensor housing first. if that doesnt work I will port my whole turbo. if that doesnt work then screw it and I will buy a bigger turbo or an external wastegate.

 

[OmegaZero]

i have the same problem, but i have a O2 dump, and still have creep

 

[awdgsx90]

well, omegazero I will be doing this project in about a month, till I get my car back from the shop. and will post it here on the forum if it worked or not. whish me luck.

 

[Norb85]

Are there any other ways to eliminate boost creep?

 

[jb talons]

Originally posted by allwheelTSI
boost creep is caused by either a leaky internal wastegate or when the internal wastegate can't handle the pressure you're running. an external wastegate eliminates boost creep.

I think you're a little wrong on this one. Boost Creep doesn't come from a leaky or weak waste gate. It comes from a waste gate that doesn't permit enough flow by the turbo. An external gate does fix the problem, not because it is stronger, but that it flows better.

This definition comes from Extreme Motorsports

Boost Creep
A turbocharged car is a positive-feedback system. The faster the turbo's compressor wheel spins, the more horsepower the engine makes. More horsepower means more exhaust gasses are being expelled. The more exhaust that is expelled the faster the turbine (and thus the compressor) wheel spins, and so-on until the engine explodes.

The ECU (sometimes via a boost controller) controls the boost level by opening the wastegate. Boost creep, in which the boost level of your engine continues to rise despite the best efforts of the wastegate, is caused when a fully-open wastegate can't divert enough gasses around the hot-side turbine wheel.

Boost creep can usually be eliminated by porting the wastegate opening and O2 sensor housing or by using an external wastegate. Both of these allow exhaust gasses to vent more efficiently.

 

[flinguist]

Will an internal dump O2 eliminator downpipe eliminate boost creep?-Thanks

 

[ltvarney]

Your best bet to eliminate boost creep is with an upgraded flapper, usually people use a 34mm one. They're around $40 + port work.

 

[eclpsegsx12]

hey, i have a 98 gsx and i recently just got a evo III 16g with the install kit......well, i put it on and i ran it at low boost and it hit 10 and creeped to 20 by 7k rpm....i tried a few things, like running it to the wastegate from the nipple on the j-pipe but nope...didnt work.....i sent the turbo out to roadrace engineering to have it ported and have the 34mm wastegate flap mod done....well, i got it back and ported the manifold and O2 housing but it STILL creeped to 20....i have no idea what to do...if anyone could help, that would be awesome.....thanks

 

[Willjs7]

did u try a different boost controller?

 

[markGSX]

I've got the same problem with my small 16G. Ported the wastegate and ported the O2 housing but still creep to 20. It's gotta be the 3" turbo-back exhaust. I'm gonna put a cat on it to see if it helps.

 

[adam355]

Originally posted by markGSX
I've got the same problem with my small 16G. Ported the wastegate and ported the O2 housing but still creep to 20. It's gotta be the 3" turbo-back exhaust. I'm gonna put a cat on it to see if it helps.

I also have this problem and I have a 2.5 turbo back and a cat.....

 

[Renagade]

well im looking at a 3" turbo-back VRS exhaust... but i keep seeing all the bad reviews about boost creep. Im not 100% sure of what it is, if its a negative thing and if its preventable. Eventually ill be going to a 2.2l with a T-28.m Please fill me in