Boost creep....need to solve my problem....port out wastegate or go an external actuator?

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (MCT_MR2)

Sun, 21 Apr 2013 14:24:37 GMT

Jay has pretty covered every aspect for boost creep (ie. the boost will continue to go up beyond the set level due to the wastegate not been able to bypass enough gas to control the boost.) Most common causes are:
- the wastegate not been able open properly (either by obstruction or not enough travel from the actuator)
- Not enough wastegate flow (wastegate port too small to flow, or too much turbulent flow for the wastegate to operate correctly, which is why some people have a divider.)

If you are able too, the first thing i would do is connect a hose to the wastegate to a pressure source that you can try with the engine off, hell even a bicycle pump. Pressurise the wastegate actuator and make sure it moves in a full range freely. If you notice it gets stopped or doesn't seem to travel very far, it might be time to take the dump off and check nothing is getting stuck.

If it all seems good, porting the wastegate port might be an option, fitting a divider or putting a slight restriction in the exhaust may help.

No extra solutions to offer, just an order to attempt things.

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (stuka)

Fri, 19 Apr 2013 12:27:59 GMT

Ive just fitted a berk dump pipe to my gen2 (sourced from Gorilla Industries) with no issue except for a modest increase in boost. Before you go removing the dump pipe again check and make sure you havent disturbed any hoses etc. The reason might be simple.

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (purple5ive)

Fri, 19 Apr 2013 11:29:25 GMT

First thing to do, take the dump pipe off and look indise where the collector is for scrape marks of the wategate flap hitting the dump pipe.
You could be experiencing what some others here have described, waste gate jamming when opening, could be jamming half way through so instead of the exhaust gas bypassing the turbine its making it boost more but just enough to cause creep
That’s where I would look first for sure.

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (darkstoria)

Fri, 19 Apr 2013 09:46:17 GMT

No it's creeping... I've experienced the overboost before and realize how it works, but this is different.....it will just creep forever and won't stop....even on factory boost (tried unhooking the electronic boost controller aswell).... So now I'm wondering what I should do in order to fix this problem.

Cheers

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (MR2QIK)

Tue, 16 Apr 2013 15:56:17 GMT

I had boost creep problems with my old K1 when I installed an Aussie DP with no cat. Common problem with such a setup. Assuming it's an actual creep (not overboost). Difference is it'll hold the correct boost for a moment, then creep up with rpm/throttle in the higher rev range.

Solutions below:

Port the wastegate opening
Restrict the exhaust (add a cat or smaller 2.5inch dp)

I added a cat (to help with the legal aspect too).

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (purple5ive)

Tue, 16 Apr 2013 15:32:44 GMT

My understanding and experience of The waste gate flap hitting the dump pipe actually makes the car not boost on low rpm, not over boost
The flap gets stuck when it opens fully hitting the elbow on the dump pipe and getting stuck, thereby letting the exhaust bypasss the turbine all the time and eventually come on boost very late. It happens on the ebay dump pipes not the berk ones afaik, and can also happen to cars that have never had it happen before (like in my case when I was on a 4 hour drive) I guess the metal flap heated up enough to expand a lil bit causing it to jam, a good fang sorted it out for me

With the boost creep you mention, is it actually creeping or over boosting (they are 2 different things almost)almost all turbo will overboost on a nice cold night with a aftermarket dump pipe, some hitting fuel cut and falling flat on its face

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (kameleon)

Sun, 14 Apr 2013 19:38:34 GMT

When you say "creep" you mean overboost right? my car with just a open exhaust used to hit 15psi on cold nights all the time. It is just what happens when you have such a large amount of flow. Ditch the CT26 as theyre rubbish anyway.

My car did make 152rwkw's with the open exhaust (hollowed out PP) and a pod filter but the power died after 5500RPM with the CT26.

Try and find a CT20B.

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (worldwalker)

Sat, 13 Apr 2013 15:07:48 GMT

This is what you need:

I don't know why none of the internal gate dump pipes for the 3S don't have it, it was the first thing I thought of when my 3S was creeping. Try cutting up a piece of 2.5in pipe into this shape then welding it in. Simplest and cheapest modification that can easily be removed if it doesn't work. Apparently (don't own one and don't know much about them) all the "better" WRX dump back systems use this design, specifically to prevent creep and from "MRT Performance" works well.

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (darkstoria)

Sat, 13 Apr 2013 14:50:07 GMT

It will keep going until it hits Fuel Cut...I have an FCD in yes and have put it up to 13.5psi
But now that I'm reading it's interesting to hear that the wastegate door could be hitting the dump pipe....but yeah mine is a berk of course suited for the CT26......this is strange indeed!

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (Scott)

Fri, 12 Apr 2013 17:43:17 GMT

I will second the wastegate flap fouling on the dump (I could see when I took it off where it was hitting). I had heaps of issues with apparent overboosting where I changed actuators and lots of other things. Mine ended up being a setting in the ViPEC which was set incorrectly. The ECU though it was hitting a predetermined boost cut thus limiting ignition and altering fuel. It was just being tricked. Anyway I would avoid boring out your wastegate as once the material is gone you can't put it back and it is very difficult to know how much to remove before you have issues maintaining boost. You may well find yourself hitting your 8-10psi and then it falling away rapidly.

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (beagle_senior)

Fri, 12 Apr 2013 17:14:59 GMT

its not the wastegate flap hitting against the dump pipe, thus not opening all the way??

I know of a few guys that have to grind off a little of the dump pipe as the wastegate flap rubbed against it, pretty sure its the berk units that it happens too

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (just_ace)

Fri, 12 Apr 2013 16:47:00 GMT

Whatsit creeping too, and do you have an fcd?

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (darkstoria)

Fri, 12 Apr 2013 16:30:14 GMT

Yeah it's a CT26 with a berk full system.
SO porting it helps?

Re: Boost creep....need to solve my problem....port out wastegate or go an external actuator? (Mrskylighter)

Fri, 12 Apr 2013 16:21:17 GMT

You can slightly port the standard wastegate which apparently helps. That's assuming your talking about a stock turbo ct26/20b etc

Boost creep....need to solve my problem....port out wastegate or go an external actuator? (darkstoria)

Fri, 12 Apr 2013 14:12:06 GMT

Hey guys,
Wondering what I can do to fix my problem....getting mad boost creep since the BERK dump went on. Now I'm not 100% but about 90% sure it's because not all the exhaust gases can be dumped and then it keeps building boost. Ive heard of either porting out the stock manifold or welding in a external wastegate and welding shut the internal one. What do you guys think ?