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

[GSXspeeddemon]

you can disconnect the wastegate arm from the flapper and if you still build that much boost it will prove to you that its creep.

However i would agree with everyone else. EvoIII are notorious for boost creep issues. Also when red_devil suggested a port job he means the turbo and the o2 housing.

 

[GSXspeeddemon]

You should search found there is a lot of useful information out there.

Found this while searching http://www.dsmtuners.com/forums/showthread.php?t=99090&page=1&pp=25
has a lot of helpful information.

 

[MidnightTSI]

Just to add on this I am having the same problem right now on my Big 16G. I just installed a way better flowing intercooler and now I am getting boost creep. I ordered an o2 sensor housing dump and new downpipe to try and fix this. I also just installed a new hallman pro rx boost controller so I can rule that out. I also ordered the 34mm flapper which I will install if the o2 dump doesn't work with the new downpipe. I also have 3" all the way back. This is weird because I already had a frontmount previous to this with no creep. I am guessing that this front mount setup has to be way more efficient for it to creep like this. I do know that 10psi feels like the previous 15psi so the car runs really good besides the creeping. It will go to 10psi in first and partially through second, the latter part of second it will get up to about 13 psi, then in all the later gears it will spike to 15 or 18 psi. This is with the boost controller turned all the way down I mind you.

 

[Eastwood95]

Just port the o2 housing or get a 2.5" one and install the bigger flapper........that will 99.99% of the time cure creep......

Make sure your port job lets the flapper door open up to as close to 90 degrees as possible. The bigger flapper allows you to open up your wastegate hole a few mm, giving the exhaust an easier path to follow.

A dumped o2 by itself will not fix the problem, you would still have the same size wastegate area and flapper hole

 

[Loewen21]

Yes eastwood that is true. But if the restriction and creep is coming from further down (02 housing, downpipe) then this WILL solve his problem. But ya porting the turbo, getting the 02 dump and a bigger flapper should almost 100% solve your problem. If not you are probably looking at a broken actuator.

 

[GSXspeeddemon]

^^^^Upgrading your downpipe actually is what causes boost creep. So buying another down pipe is not going to help. Buying an o2 housing with a dump will help but not eliminate it. Eastwood is right and you also have the alternative to port the hell out of your 2g o2 and turbo.

 

[TURB0]

What is the best way to remove my wastegate actuator arm?

 

[Eastwood95]

take the retaining pin off that holds the arm to the turbine housing

 

[JohnCIV_Talon]

I recently had a megan racing dowpipe, custom 3 cat back and a high flow muffler put on (suprisingly quiet and awesome sounding by the way). In 4th gear the boost never drops but just climps to 17, sometimes 18 psi and I hit fule cut. I was wondering if there is anyhting I can do. I have turned it down alot and still keeps creeping up to that. It really is unbelievable what the performance gains of a exhaust are though, i hold boost so much longer.

 

[IslandTSI]

Port the turbine housing and o2 housing is all you can do. Or switch to an external wastegate.

 

[RotaryAE86]

i have the same setup for exhaust but no problems, 17-18 psi is what your boost controller is set at?

 

[JohnCIV_Talon]

No, I cant really tell what its set to cause of the boost creep

 

[DGajre777]

If you can't tell what you set your boost to, then you probably installed your boost controller wrong (if you have one).

Fuel cut suggests that you have a boost leak - do a boost leak test!

 

[kenamond]

Test your WGA while you do the boost leak test. If you hook a vac line straight from the compressor outlet to the WGA nipple and do the boost leak test while watching the WGA arm, it should open at 8-10psi. If you have a pressure tester, you can hook it straight up to the WGA and see if/when it starts to move the arm.

If it doesn't open, disconnect the WGA arm from the lever on the turbine housing and make sure you can turn the lever easily with your fingers (cool motor!).

If all of that works, pull the vaccuum line off the intake pipe and cap it, then hook the vaccuum line up like I first said (compressor-->WGA) and do a full boost test drive and see how it boosts.

If none of this works, make sure you don't have a leak in the vac line from the compressor housing to the WGA.

If all that checks out, it sounds like creep to me, though I never thought a T25 could.

By the way, fuel cut is the ECU's way of protecting against failed WGA. It senses too much airflow, assumes too much boost, assumes this is due to faulty WGA, cuts spark and fuel.

 

[IslandTSI]

My t25 creeped all last year. Up to 19plbs at times, then it would drop off. I ported everything this winter so we shall see what the results are. And I'm going to replace all the vacume line just to make sure there are no leaks.

 

[JohnCIV_Talon]

I have the boost controller set up properly, i know that much, i know its creeping, what I dont know is if I got a boost leak, ill check tomorrow it rained all day today. I know that fuel cut is caused by air but I thought if you were boosting to high you would hit fuel cut also? Becasue the only time it cuts is 17 or 18 psi. It is possible I have a leak at 17 psi I guess.

 

[oldman]

I have the boost controller set up properly, i know that much, i know its creeping, what I dont know is if I got a boost leak, ill check tomorrow it rained all day today. I know that fuel cut is caused by air but I thought if you were boosting to high you would hit fuel cut also? Becasue the only time it cuts is 17 or 18 psi. It is possible I have a leak at 17 psi I guess.

You'll not flow enough air at 17psi with a T25, not even close, unless you have boost leaks. Does boost hit a lower level first, then slowly creeps up as rpm increases OR does it hit 17 psi right away.

My t25 creeped all last year. Up to 19plbs at times, then it would drop off. I ported everything this winter so we shall see what the results are. And I'm going to replace all the vacume line just to make sure there are no leaks.

Are you sure you're not talking about boost spike?

 

[IslandTSI]

Yes, I know the difference. It does spike in the lower gears to over 20psi if I am not careful. What I am talking about is a pull in fourth where my boost creeps up to 19ish/lbs before it drops.

And my actuator works perfectly. I had to fix a broken manifold stud this winter so I took everything apart and ported it. Hopefully it helps somewhat.

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[kenamond]

I should polish my old T25 practice port job and see if I can sell it to one of you guys. Just collecting dust on a shelf. Too bad I ported it for the 7cm² gasket.

 

[IslandTSI]

That shouldn't matter. I ported my manifold to 7cm as well. I dont know how much it's going to help but it wont hurt. The only issu I have now is that I cant find a small enough flap wheel to poslish with. No one around here has anything less than a 3" one.

The turbine housing in my pics looks really rough, but its actually quite smooth to the touch,

 

[kenamond]

That shouldn't matter. I ported my manifold to 7cm as well. I dont know how much it's going to help but it wont hurt. The only issu I have now is that I cant find a small enough flap wheel to poslish with. No one around here has anything less than a 3" one.

The turbine housing in my pics looks really rough, but its actually quite smooth to the touch,

Well, I don't think it would be super great to use my turbine housing if his exhaust manifold was still stock.

Flapper wheel and some sand paper do wonders. (proud papa):

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[IslandTSI]

Wow, looks nice. Do you think it will make much of a difference if I dont polish my turbine housing like that? I'll still go to town on it with some hand sanding but it will never be that smooth.

Or should I keep searching for a flapper wheel to use.

And OP sorry for jacking your thread. I hope this is useful to you anyways

 

[oldman]

^^^Show off!!!

IslandTSI, Picture #3 O2 outlet, take out the divider where wastegate path merges back into the main path.

 

[IslandTSI]

I was wondering about that, how much is safe to remove? If you want to do me a big favor you could trace it out in mspaint for me.

I'm just worried I;m gonna go through somewheres and make a hole I cant plug up with a mig welder.

 

[JohnCIV_Talon]

It hits a bout 16 in 2nd and goes to 17 then drops down slowly, in 4th gear it does the same thing but to like 18 psi. I think I turned my boost controller all the way down and in second now It didnt go to 17.