So ive been having this boost creep issue lately. A little background for you guys: IX w/ TBE, 02, intake, EBC, stock turbo, Custom tune.

So i hold 22psi all the way to 5.5k rpms then it shoots up to 23-24psi. This wasnt happening when i was getting dyno tuned 3 weeks ago. Started a week after the tune. Started just at night when it was cold. Now it is doing it all day long.

So tonight i turned off the EBC. It held 12.4psi till 4.5k, then 13-15psi till 5.5k, then shot up to 21-22psi, running off just wastegate.

Im confused, how do i fix this? Would adjusting the preload on the stock wga help?

 

prob your 02 housing

 

Pretty common for some of the 02 housings. Which one do you have Chuck?

 

hope its not the e-bay version.

 

list your mods, sounds like o2. Also, hows your ebc hooked up?

 

I got a ebay 02, a good megan replica piece. My blitz id3 is hooked up correctly, never had any issues. I held 22psi to 7k and loved it. A week after my tune boost just started creeping, and seems to be slowly getting worse.

 

If I lived in the Bay Area Iīd just call, razorlab, over in Alameda and have him alter your IXīs ECU-based, boost control system, thus eliminating the need for EBCīs or MBCīs. Super-stealthy, and functions efficiently as a closed-loop system, with built in error control.

Sell the EBC and youīll have no real need to spend more money purchasing an aftermarket H.D. WGA that you shouldnīt really need for running 21 PSI on pumpgas anyway.

However, if you like fidgeting with gadgets and are really hooked on your EBC, then youīll probably need to try a H.D. WGA. In which case, the Forge unit is probably the best on the market. Then set preload to 17-18#. If this shouldnīt happen to cure the creep, then youīll need to remove the turbine housing and port out the wastegate bypass port to improve flow.

EDIT: To answer one of your original questions, yes you could try adding more preload to the WG. It might work and then again it might not. But, it wouldnīt cost you anything to try and as a bonus, itīll give you an improvement in turbo spoolup.

 

iven been having boost creep also but only like 1psi no more, this happend when i installed the buschur racing 02housing in 5th gear i floor it at 2500rpms once it gets to 3500rpms it spikes to 1.36bar then by 4800rpms it creeps up to 1.41bar and stays there this is like .8psi maybe this isnt significant as your whick climbs up to 24psi.

 

I was going to say the exact opposite. I was wondering if the original poster has a high pressure actuator because those tend to cause creep, especially with a tubular O2. If you have creep, the last thing you want is a stiffer spring actuator. Also, I think he needs to try reducing preload on the actuator, not adding it. If the actuator is too tight, then the wastegate may not be opening fully, which could add to the creep problem.

Very odd that it's getting worse though? Is the weather getting colder there?

 

Sounds like boost creep from the O2 housing. Probably has a small hole where the waste gate flow joins with the turbine flow. People are having good luck getting rid of the boost creep by opening up that hole.

 

mrfred could be right. The boost creep phenomenon is caused by an inability of the WG bypass port to bleed off enough of the exhaust flow from the main turbine scroll area. It can either be caused directly by too small of a bypass port or too sharp of a transition from the main scroll into the wg bypass port or a bottleneck further downstream as in what mrfred is decribing caused by a restrictive merge within the O2 housing. There were reports of this in an earlier thread a couple months ago and pictures of a ported O2 housing which cured the problem.

 

He states in his original post that when he turns off his boost controller heīs only seeing 12.5 PSI. That means that his WGA isnīt adjusted too tight. In fact, if itīs at 12.5 PSI, itīs already loose. He really canīt reduce it much lower than 12.5 PSI...maybe he could loosen it down to 11 PSI. Although Warrtalon mentions a theoretical case where negative preload is possible and I guess it could be possible if you had an extra long actuator rod.

At 12.5 PSI the actuator rod isnīt near being short enough that it would cause binding on a stock WGA. Bind might come into play at preload levels above 23-24 PSI of, some, not all cases, maybe.

Why is a properly functioning HD actuator the last thing that youīd want if you are experiencing boost creep? A properly functioning and setup WGA should in no way impact on the creep phenomenon. As, the only case where it is possible would be if preload were to be so excessive that it would cause bind and incomplete flapper valve lift and I donīt think thatīs gonna happen below 22 PSI of preload normally on a HD WGA, and this guy states that on wastegate alone heīs only seeing 12.5 PSI.

 

I said in my orig post that i am building up to 21-22 psi off just wastegate.

 

That is what i am thinking. I am on the stock wga. I think i will try to reduce preload, seems like my actuator is not opening fully, causing my boost to reach 22psi on wastegate alone(boost controller off).

 

I dont want to ditch my EBC. Ecu based boost control will taper at high rpms. My blitz unit will hold 22psi up to 7k no problem.

Looks like i will try to reduce preload on my wga. If that doesnt work i will order an FP green with a HD wga. And prolly port my 02 while its off the car.