Hiya everyone.

Recently, I had my Haltech, exhaust and other upgrades installed.

As soon as I got my car back, I realized there was massive boost creep. I hit 14.6 once halfway through third gear, and usually 13 or so in second gear.

So, I decided to try to resolve this issue with a bandaid until I can afford to swap it all out (FMIC and T04).

Would an S5 turbo, and a heavily ported wastegate be enough of a step up to combat my boost creep?

My ideal boost would be 12psi on the dot, but not much higher.

Would buying someones used S5 Turbo and Manifold (Is that all I would need for the swap?) and porting the new wastegate be enough of an aid against boost creep?

Since I'm running a 3" exhaust, could I use a smaller gasket (2.5" or so) to create extra backpressure against the turbo if I'm still experiencing boost creep?

Which one should I try first? I'm desperately trying to fix this problem.

 

Try porting the WG on your current turbo first. Sound slike you are not hitting much more than your ideal, port it as big at the cover and it should be fine.

 

I did. It's ported to the max.

 

If you plan on buying a FMIC, and a T04 ... then why **** money away on a S5 turbo now? Not sure if it would even cure the problem .. but either way sounds like pissing into a stiff breeze. Put a more restrictive intake on the car until you can afford to complete it right, ... and be done with it.


-Robert

 

the series 5 turbo may still creep, but it will not be as pronounced. Likely it will keep you within your boost range.

 

Bump bump.

 

With the RB turboback and the 3'' TID I can understand your hellish boost creep. I have a s4 turbo with the wastegate ported to the max and I still get creep in cold weather to 13 pounds. A series 5 turbo/manifold with ported wastegates should be able to hold boost under 12 pounds.

 

Ported to the limit of the stock flap or did you fit a bigger flap?

 

Limit of the flap I believe.

 

Get a bigger flap. You can go much larger in the port size, like double the area of where you are now. You'll never control boost properly otherwise.

 

Could you elaborate on that any more?

Seems like a great solution, I just need to clarify how it works and what to ask for when I talk to my engine builder

 

The stock flap is very small, but swapping a bigger one on allows you to port the wastegate much bigger. Any turbo shop will be able to do this. For a DIY solution read the thread in the archives.

 

Sounds great. I'll give my guy a call on Monday and hopefully arrange something like this.

After doing this, is my boost going to 'go up' to whatever value it was creeping to before, or is it going to keep it in it's place?

 

I just finished porting the stock wastegate on my S4 turbo and installing my RB 3" turbo back exhaust. I had a stainless steel washer welded onto the stock flapper to increase it's size and I can keep the boost down to 5 lbs. Sometimes it'll creep up to 6-7 but by then I'm going way too fast. I am still using the stock intake so that's also helping keep boost down. I did everything myself (except the welding) and I'll see if I can get a pic of my new flapper up.

 

That's a good idea, I might try that. I was going to use the much larger flap from a 12AT exhaust housing but your idea seems much easier.

 

I got that idea here on the forums. The washer was convenient and it welds nicely to the stock flapper. I like that because it pivots and moves like the stock flapper and makes it easier to seal. Still working on getting those pics, they're still on the camera and then I gotta resize 'em. someday they'll be up on my site.

 

here are a couple of pics, they're a little big. The guy that welded the washer on ground the face of it flat afterwards....you can't even tell it was a washer.

 

Looks badass, Twisted.

Are there any problems or side-effects you've run in to?

What's your setup, and how does it fare against boost creep?

 

Thanks for the compliment. No problems or side-effects for the past month. I also removed the twin-scroll flapper and actuator while I had the turbo out but with the RB exhaust it still spools up really quick. The only time I've gotten it to creep past 6 psi was in 5th gear, cold night, going way too fast...it hit about 7 psi. A more open intake would probably make it creep a little more.

 

Hey, Silver, could you send me an AIM at wompa164?

I have some questions for you.

 

Is boost creep always a bad thing? I mean, if you are able to supply the proper fuel, would it be ok. I have a series 4 turbo and will be running a full 3 inch exhaust and freeflowing intake. I will be running a Microtech with 720 secondaries. I did port the stock wastegate to as big as the stock flapper would allow but if I do boost creep, it wouldn't be bad right? If I can supply the proper fuel, wouldn't the creep just give me more power?

thanks

 

Not when you're creeping to my levels.

Above about 12psi or so, you're putting damage on the turbo, and run the risk of detonation with hot intake charges from inefficient intercooler.

 

Only to a point, and then you start going backwards. This is because boost makes heat, and if you boost higher than the turbo's peak efficiency point the turbo outlet temps start skyrocketing. It you want to avoid detonation to need to dump in lots of extra fuel (to cool the air/fuel mix) and/or severely retard the igntion. Both of these reduce power output.

I have heard of cars tuned to run high boost making more power when the boost was turned down because the mixtures could be leaner and the ignition could be more advanced.

The amount of boost you run should be governed by your turbo. Keep boost where the turbo works best.

 

Ok, that makes alot of sense. I guess I just gotta get my engine up and running and see how bad the boost creep is gonna be. Or I could take my turbo apart again and get a new flapper welded on while it's off of the engine.

thanks for the replies

 

Hmm.

My man said this kind of job would probably take 6-8 hours.

That's like $300-$400 bucks at $60/hr.

I don't have that kind of money. That's 1/3 - 1/2 of a new intercooler or lots more things I need more.

What else can I do, now? Just put a bigger restriction on the intake?