Boost Creep - No Boost Leaks

[Fubar231]

So i have no boost leaks (Tested with a air compressor). No form of boost controll right now (Took my MBC off, should be getting a EBC soon, MBC was also a bleed style causing a leak)

Anyways, i did all my boost leak test stuff, got them fixed. No more leaks. Now the problem is, my boost creeps from like 7-8 lbs up to 15lbs.

Mods are: Apexi Filter, Cooleze intake pipe, 2.5 in hardpipes w/ spearco replica, walbro 255, RC 550's / Lex Afm, 57trim ct-26 built by DriftMotion, custom thickness cometic headgasket, arp head studs, TMS downpipe w/ integrated elbow, blitz nur spec exhaust no cats, aem wideband, egt/boost gauges etc. I think thats all preformance related.
(Still on stock fpr if that matters)

Anyways, boost creep. Down low at around 2500 rpm it will be about 7 psi, but once it gets up to around 4k - 5k its up around 13-14 and just goes it. It just slowly creeps up with the rpms. I may try and get a video of it tomorrow, but does anyone know what could cause this?

Any help is appreciated!

Thanks,
Shane

 

[dumbo]

Did you check that the WG opens fully and diaphram isn't leaking?

 

[Fubar231]

Did you check that the WG opens fully and diaphram isn't leaking?

I tested the wastegate before the turbo was put on the car, and running 15psi out of my air compressor opened it wide open.

 

[dumbo]

:roflid it crack at 5-8psi? I'm sure your regulator only went down to 15 right, but isn't that where you boost stops creeping? More than likely a coinencdence.

Check it now since its mated to your down pipe and see if it fully opens. Mine did the exact same thing(Made me shit my pants on my na-t the first time) and it turned out the WG has hitting my knock off downpipe.

 

[Fubar231]

Is there any way to check it with out pulling the downpipe off the back side of the turbo... thats such a pita... I mean im not worried about it as long as it stops at 15 once i put the EBC on cause thats what i plan to run daily, but... i don't know where im going with this. Guess i could report back once i get the EBC on, (Should be tomorrow, mi getting a ebay knockoff EBC for 40$) But, any other sugesstions?

 

[dumbo]

Just hook up the compressor to the WG line and put 15psi to it and see how far the linkage goes. IIRC mine was hitting on the outside.

 

[Fubar231]

Just hook up the compressor to the WG line and put 15psi to it and see how far the linkage goes. IIRC mine was hitting on the outside.

Thank you!

Your gonna save me tons of time. Ill do that tomorrow and make sure its all good to go.

 

[grimreaper]

if you disconnect the wastegate actuator to door rod, you should be able to open the door by hand. Is there any preload on the wastegate? the above method with an air compressor works to make sure it opens fully but its hard to find the exact opening point with a regular shop regulator.

 

[MacDaddy_J_420]

Welcome to the wonderful world of the 57 trim. Mine creeps all the way up to 16psi and then finally hits a wall. If the waste gate is functioning like it should then you can always try to enlarge the wastegate port so it will flow more exhaust gases. It didn't really help when I did it, but maybe you will have more luck. If you had a divorced dp it would be even worse.

 

[IJ.]

Welcome to the wonderful world of the 57 trim. Mine creeps all the way up to 16psi and then finally hits a wall. If the waste gate is functioning like it should then you can always try to enlarge the wastegate port so it will flow more exhaust gases. It didn't really help when I did it, but maybe you will have more luck. If you had a divorced dp it would be even worse.

I was wondering if that wasn't the case!

 

[dumbo]

My na-t with a 57 trim, 3inch ddp(recirced) 550's ect, would hit 8psi quick and hold even at about 5 or 6 celcieus out.

 

[IJ.]

My na-t with a 57 trim, 3inch ddp(recirced) 550's ect, would hit 8psi quick and hold even at about 5 or 6 celcieus out.

Pardon??

Your WasteGate would hold temperature?

 

[dumbo]

Pardon??

Your WasteGate would hold temperature?

LOL, ambient temperature.

 

[Fubar231]

Welcome to the wonderful world of the 57 trim. Mine creeps all the way up to 16psi and then finally hits a wall. If the waste gate is functioning like it should then you can always try to enlarge the wastegate port so it will flow more exhaust gases. It didn't really help when I did it, but maybe you will have more luck. If you had a divorced dp it would be even worse.

Ok, since you ran a 57 trim got a question. Did you use any form of boost control? Cause if i run 15 psi, and it spools down low, spooling not creeping, will it continue to creep to 16 18 20 etc.?

Also, i didn't have any time for the supra today. Been a busy day.

 

[MacDaddy_J_420]

Fubar231 - I am using a hks ez as my form of boost control. I have it set to 13-14psi, which it will hold at lower rps up untill around 3500-3800 rpm. After that it will pick up and begin creeping up to 16.xx psi. When getting the car dyno'd we confirmed that this was where it stopped over boosting and leveled out. This is a issue that is caused by the cold side of the turbo being too large, very common is DSM vehicles, but the creep on their vehicles is a lot worse. I am not quite sure what you are asking, but I hope it helps

 

[bountykilla0118]

External wastegates are your best bet to stop boost creep or get a bigger bolt on turbo because..... the ct26 housing is too small and so is the flap inside of the housing for the amount of air that is flowing through

Mac-d whats good man ..... give me a buzz i lost your number a while back

 

[MacDaddy_J_420]

^ I second that.

bountykilla0118 - Man I have been busy as hell with school, I will hit you up and tell you whats all been going on with the car.

 

[paradox616]

with no cat, a 3" DDP and 3" cat back on a 57Trim i had boost creep much the same, worse on a stock ct26, only started when i removed my blocked cat. i guess its the price you pay for a free flowing exhaust. my new turbo has a larger waste gate and does not have the same issues.

 

[dumbo]

Odd...

 

[hvyman]

i have a 57trim and have no creep.. well a lil in the sorta high rpms(high for me) like 4500-5k but it only creeps like 1-2 psi. this is on a stock gauge tho but it has never gone past 8.(i have 1 washer on). and before the washer i only hit 8 a couple of times when it was like 35*f out.