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

[Gman12263]

Alright, I'll get on that BLT.

What's the advantage of a fuel pump rewire though?

 

[curt-s]

Read articles within edge1g's link.
Thoroughly.
That's what the knowledge base is for.

 

[blktalon3]

The bigger wire you use with a rewire supplies the fuel pump with more consistent voltage in higher rpms

 

[Chumpaumpalumpa]

Please take care of this:
http://www.dsmtuners.com/threads/dsm-maintenance-guide.476550/
Then do this:
http://www.dsmtuners.com/threads/basic-horsepower-ugrades-2g-4g63t.480196/

 

[PlanZero]

Before I go purchasing a ported or aftermarket 02 housing I want some input from my fellow DSMers. This is a stock T25 Tsi, with 2.5"/3" downpipe and catback, cat deleted. Also an injen intake and nxs MBC. Even before I installed the MBC my boost would fluctuate back and forth from 10-15 or higher. I realize this is common when a catless 3" exhaust is installed, but everything I've read is with a 16g. Obviously I did a BLT several times and no leaks. I just want to make sure this is common with a t25 as well before I either get a better O2 housing or look for problems elsewhere.

 

[Maes]

I've only seen boost creep when a larger dp is installed. To get rid of it you normally have to port the flapper area and O2 housing area and it takes care of it

 

[gst-turbo]

I been struggling with boost creep for a long time. I had a 14b turbo and a 3 inch straight Pipe exhoust with no creep. Then my turbo started to go out and I got a small 16g turbo and first time i stepped on it I hit 25 psi with no fuel cut. I drop the turbo down and install an o2 dump but dident help then I dropped it down and ported it as far as it will go. Then I ported the stock manifold to 7cm like the hotside. Then I ported the stock 02 housing and with so much porting the spool up is crazy fast. I seen countless threads about it and don't really want to go external for such a small turbo. I have a hallman mbc hooked up correctly. The waistgate is not oem and I tried both aftermarket and oem and still nothing. Is my only two options putting a stock exhoust and external? Any other tips?

 

[FIBA M - EC17PSE]

Go to a smaller DP size to restrict it a bit! I say restrict it but really its not restricting it alot but it helps more then a full 3" system.

 

[Dsmkauai]

Or try a holset actuator worked great for me.

 

[JusMX141]

Sounds to me like your wastegate actuator isn't opening....something's wrong if you have zero boost control on a bone-stock Small 16G. I ran one for a year or two on my daily driver and boost was rock-steady at whatever level I wanted to run, even with a full 3" exhaust, no cat, and a ported 2G o2 housing.

 

[FIBA M - EC17PSE]

buy one of these as its fairly cheap and you can adjust springs inside to help with your needs! http://www.ebay.com/itm/Billet-Adju...bishi-4G63T-TD05H-EVO-3-VR4-DSM-/182376988679

this should help you out if your gate is broken, I misread and thought it was an evo 3 16G and not a small 16g so my bad on that so ignore my exhaust talk as thats mainly for the e316g turbos

 

[gst-turbo]

I'm going to install a actuator I have laying around to see what happens. If not I'm going to go with the above chooses of actuator. What the proper way to install an actuator? My current set up is I have a washer on each side of the bolt and it's a tight fit. And if I have no washers it's just flops around

 

[JusMX141]

Shouldn't need any washers at all if the actuator head isn't smashed inward and the lever on the turbine housing is in the correct position. With the actuator mounted securely on the cover you should have to pull the arm out about 1/8" or so to hook it over the pin to get the correct amount of preload....in other words the pin should offset the hole about halfway prior to installation.

 

[Jay 97 GSX]

Ok so i got my Trans Rebuilt and now im finally able to drive my 97 GSX, still havent plated it yet tho.

But before i do anything, Im buying a Boostleak tester or building my own to do a boost leak test. once the boost kicks in past 10 psi at high RPM the boost is getting so high and causing a sputter. ITs almost like a Fuel Cut. I had fuel cut on my last GST and it doesnt exactly bang like fuel cut its more moderate. Definitely scares you a bit. Im thinking because my GSX is mostly stock besides it has a 3in megan Downpipe with a 3 inch greddy exhaust. Would the 3 inch Downpipe cause the boost to creep above stock levels? I do have a ported Hot side i can throw on if that will make a difference. Ill check for leaks first then if you guys can confirm that the 3 inch downpipe is the issue then ill try to throw on the ported 02 housing. Let me know guys. never ran into this issue before as in my old gst i had a 2.5 downpipe and exhaust.

 

[pauleyman]

You have no profile. Yes a 3inch exhaust will cause creep on a stock turbo.

 

[doubleclutch]

@pauleyman Can you even hit high enough air flow numbers on the t-25 to hit fuel cut?

 

[pauleyman]

@pauleyman Can you even hit high enough air flow numbers on the t-25 to hit fuel cut?

Honestly I'm not sure. I never hit it in a 2g.

 

[Jay 97 GSX]

Honestly I'm not sure. I never hit it in a 2g.

I feel like the since the exhaust is 3 inch from the down pipe out it causes the boost to creep because something with the gasses isn't doing something right, I'm not exactly sure but its what im thinking. very hard for me to explain it. I'm still learning all of this. its either this is the issue or i have a major boost leak somewhere but ill find out this week. I'm going to get the exhaust switched to 2.5 and see where that goes.

 

[pauleyman]

Boost creep is easy to explain. Wastegate doesnt flow enough. If you let the turbine breathe but the gate can't bypass enough to keep control when its open boost will continue to rise.

 

[Jay 97 GSX]

Sounds like i need to port my wastegate.

 

[FallenKing]

What kind of BOV do you have? It may be letting boost out at higher RPMS b/c it's set to 8PSI but not all of it so you'll get a sputter effect. If you have a boost controller I would close it to stock settings see if you still have sputter. if not then you just need to harden your BOV or get a new one.

 

[doubleclutch]

As far as I know, the t-25 cannot create enough boost to creep. Creep typically occurs at higher RPM due to the larger volumetric flow of the engine. At higher RPMS, the t-25 cant even make 15psi.

I had a full catless turbo-back on my t-25 and no creep whatsoever.

I think the biggest question is, what turbo are you running. You really should create a profile.

 

[PlanZero]

I had boost creep on my Tsi with a t25 and 3" exhaust with no cat. Put a tubular o2 housing ($50 eBay Megan knockoff works fine, just check the flange with a straightedge first) on and it'll go away.

 

[Jay 97 GSX]

Yea i haven't had the time to make a profile but its the stock t25.

 

[AWD-Tony]

1. Boost/Vac/Exhaust Leaks - NONE
2. Mechanical Timing - 8 degrees
3. Base Timing - 5 BTDC
4. New NGK plugs gaped to .28 (7 series) - Wire visually look ok
5. Motor Health - Dry 1: 110 2: 115 3: 115 4: 120
6. Throttle Adjustment - switch/cable/tps are all in line
7. Compression Ratio - Stock I believe
8. Wiring & Sensors - Everything seems to be working properly. Replaced front 02. Knock sensor is leaking.
9. No CEL codes
10. Electrical system - Link tells me we're at 13.5 volts
11. Base Fuel Pressure & Injectors - No AFPR - Rewired 255 Walbro (measured +14 volts at pump) RC 550s. Stock FPR is not leaking
12. WB sensor - There's no calibration for AEMWB. I spoke to them directly. Actually cleaned it yesterday by soaking in seafoam. It's about half a volt off from the gauge reading. I've tried all the other inputs in link.
13. 91 or 93 octane
14. I've watched all the demo videos in link several times

So I'm trying to get this car tuned but it has boost creep/over boost as load increases. I'm guessing this has to be addressed first before starting to dial in WOT.

Car has HKS EVC EZ but I made a MBC to eliminate that it's the BC causing the issue. I did a boost leak test at 30psi. It holds for about 30 seconds but I hear air moving in #3 or #4 cylinder between the spark plug and injectors...IDK if this is normal. Sprayed soapy water everywhere and nothing visible. Applied compressed air to WG and it doesn't take much for it to fully open, less than 5 psi. On WG pressure it climbs to 20psi on the big end. IDK if it was ported under the flapper. It does have O2 dump to atmosphere and also has 2.5 - 3" and no cat. Big 16g btw. I've read that it's a common issue with the 16g's with this set up. Does anyone know if there's anything else I need to check before I remove the turbo to see if it was ported? Thanks