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

[DSMcamaro]

Hi fellow Dsmers. l purchased a big 16g from SBR and right after intalling it to my surprise i got boost creep.

You must not have researched. .

1. You should fill out your full vehicle profile with all your mods.
2. What size exhaust are you running?
3. Did you port the 02housing?
4. Do you have a boost controller and if so, what kind of psi are you running?

 

[boostnhard]

3inch pipe
no ported o2 housing
i was running a mbc i thought that was the problem and removed it.

 

[boostnhard]

Ok Dsmcamaro, thats whats wrong with my car(1-4) what should i do?
sorry about the newbieness

 

[b00stedtalon2]

To help the creep you could port your o2 housing or upgrade to a bigger o2 housing, or get a bigger o2 housing with dump!

The o2 dump on my daily driver fwd talon made boost creep nonexistent.

 

[95undrpsi]

I will agree, get a new o2 housing. I had the same problem when I put on my 3inch exhaust to my stock 02 housing.

 

[Zack Huffman]

^^^ X3

Port the O2 housing, especially where the WG outlet is, or porting the WG does nothing for boost creep.

 

[DSMcamaro]

Port your 02housing. What psi is you MBC set at and how far is it creeping? If your running with no boost controller right now and expecting it to hold at 8-10psi, good luck. If you have all the supporting mods to run about 14-16psi, with a a proper port job, you shouldn't have any problems.

 

[boostnhard]

ITs creeping 20+. the MBC l removed it thinking that was the problem. So my 02 housing is the problem for sure! Does it need to have an external dump? I wouldn't like to have any hot air melting stuff around.

 

[boostnhard]

Hey guys thanx for replying. l just updated my profile with all my mods if that helps at all.
Forgot to mention the gasket between the turbo nd the exhaust mani cracked and now i have a bit a leak could thathelp to the problem? Also i think me WGA is not working how can i make sure?

 

[oldman]

Hold up, are you sure you have boost creep? At what rpm do you hit 20psi?

 

[boostnhard]

5.000 - 5.500 its at high rpm why?

 

[oldman]

5.000 - 5.500 its at high rpm why?

Just making sure, many people confuses infinite boost with boost creep.

 

[RBurroughs]

I was getting my car dyno tuned yesterday on my Evo16G, and on the first run found I had some bad knock. When I checked the boost level, I saw it was reaching 23-24psi by 7000rpms. For a 16G, I thought it would have little lag, but the psi rises so slowly and continously I think it might be boost creep. I ran the actuator line strait from the source, BOV T, with no controller, and it still spiked up that high.

I have a stock o2 housing, 2.5" downpipe.

Could it be the actuator arm or boost creep

 

[paper_clip_boy]

I would HIGHLY suggest that you upgrade that downpipe to a full 3inch unit if you plan on recirculating your wastegate back into the exhaust, If you do go that route of getting a new 3inch downpipe, upgrade to an EVOIII O2 housing and get that proffesionally ported. My buddy was having the same problems on the same turbo and corrected it by doing that. If you would like to keep your 2.5inch downpipe then consider running a dump off the wastgate passage. Also look into porting your wastegate hole larger just enough so the flapper seals it. Another option is to Get a 34mm flapper installed and port it even larger than what you can with the stock flapper.

Boost control is key and in my opinion, Tuning is useless until you correct that problem first.

I would do the downpipe, EVO III O2 housing, and 34mm flapper. Its a good thing to get out of the way now. If your goal are no more that 350whp and sticking to that turbo, you will love that you have upgraded now, before something blows up.

 

[kenamond]

Creep on a evo3b16g with a larger exhaust is common. Some fix it by porting the WG entrance in the turbine housing, others fix it by upping their mods to handle 20psi (that's usually what the creep settles at - yours seems a bit higher). Others upgrade their WG to one on the ex mani or one built into the O2 housing (not familiar with the evo3 o2, but maybe that's what it does). Basically, the flapper goes away so that the hole is wide open, then a separate WG like an external handles the WG flow).

Part of the problem is that the stock WGA doesn't have enough throw to open the flapper up more than 45* or so.

As for porting out the WG hole to be larger and upgrading to a larger diameter flapper, there may be problems there, too, as the backpressure in the turbine housing can push the larger flapper open at low boost causing slower spoolup.

If the current WG setup is the problem, you have to mod something, period. For more info, search for creep. There's a good tech article related to this exact problem, too, and the author cured the creep by porting the turbine and o2 housings to improve flow through the WG passages.

Like I said above, there are a few things to do to cure it, but none are simple fixes.

Oh, and there is a good test to see if it's WG flow. Disconnect the actuator arm from the lever on the turbine housing, verify that you can turn the lever with your fingers (cool motor!), and do a full throttle pull while monitoring the boost gauge. If it creeps past a few psi boost, it's most likely creep. If you can't turn the lever easily with your fingers, the WG may be obstructed.

 

[funkbuster]

Hello. I have a 93 talon TSI. I have a 3"dp and 3" testpipe, 2.5" exhaust back to axle and stock muffler, rest of car is stock, except the guy I got it from "bypassed emissions". I have a quesion about hooking up a MBC. I have a SBR MBC, hook it up, and boost shoots way up, hook up stock one, and boost stays around 12, on stock guage. I am hooking it up from the j-pipe to the end of the MBC and from the 90 degree plug on the MBC to the WG. I took it off for now until I get a boost guage, I plan on getting one next week. I was wondering how I should hook it up, with all the hoses my car is missing. I was also wondering if these hoses missing could be the cause of my idle surge when the car is warmed up, car goes up to 1500 then drops to 1000 and back up constantly, when at operating temp.

1st pic is where I have read to hook up the boost guage, but what hose does it go to, notice the top two are jumped together.

2nd pic is throttle body, is it fine to have these hoses blocked off? Could this cause my idle surge?

Thanks for any help in advance
Chase

 

[funkbuster]

so it is that confusing

 

[kmoore]

First, how do you know that the boost is staying at 12 psi on the stock gauge? The stock gauge has no numbers on it. You should really get a boost gauge and see whats really up. For the boost gauge you want to tap into the fuel pressure solenoid which, I believe, is that vacuum hose coming from underneath those electrical sensors.

Here is a link that i found from 1 minute of searching- http://www.dsmtuners.com/forums/showthread.php?t=79279&highlight=where+to+tap+into+for+boost+gauge

For you second question- I can't really tell in you second pic but do you even have a BISS?
I can not help you on the elimination of the vacuum hoses because i have very little knowledge about the subject

Have you done a boost leak test to make sure your other vacuum hoses are not leaking?

 

[n55long]

actually on his model 90-94's they do read boost pressure on the stock gauges, it goes 0-7-14 psi

 

[UKNOWHO]

actually on his model 90-94's they do read boost pressure on the stock gauges, it goes 0-7-14 psi

the in dash boost gauge is in accurate u need an aftermarket boost gauge to ideally measure boost

 

[kmoore]

actually on his model 90-94's they do read boost pressure on the stock gauges, it goes 0-7-14 psi

I apologize. Im a 2g guy

 

[funkbuster]

yeh, I understand about the inacurate boost guage, but with the stock BCS it stays between 7 and 14, looks like it is at about 12, but when I hook up the MBC it shoots to the top. I hooked up a boost guage I had to the one line comming from my FPS, but it wouldnt ever read any boost. The 1 line running from the FPS goes to the fuel rail, I dont have one running to the intake manifold. It does have a BISS, it is screwed way down in the hole. I just assumed the boost guage that I had, came with the car, didnt work, but I will try it if I can figure out where to hook it up.

 

[DJYoshaBYD]

well.... I believe that you have the boost controller hooked up wrong... I made a MBC and you have to hook up the bottom nipple to a vac source after the turbo so it can get boost, not vacuum... your wastegate is staying closed because there is no pressure to move the actuator because the air is being sucked instead of blown... if you leave it hooked up to the J pipe, the it will ONLY get vac, because the turbo is only going to suck in air from that side of it...

 

[funkbuster]

that is how I had it, the bottom is going to j-pipe and the side is going to the WG

 

[DJYoshaBYD]

no.... sorry if I was confusing... the MBC should not be hooked up right there... you need to hook it up to a vac line that is AFTER the turbo... I have mine hooked up to the line for the blow off valve... I know some people say dont do it there, but it will work fine and other people do it and it works great.... the j pipe is going to be sucking air instead of blowing it, putting load on the ball bearing and spring in the MBC... hook it up to ANY WHERE ELSE but there... it has to be something that when you boost, it will be boosting through the lines, not drawing vac.... is that a little better?