I turned my car down to 11psi for awhile because I noticed I was getting a little boost creep, mainly up to 15psi, maybe 16... Well today its boosting like normal until I get on the highway.

Theres this guy following me (I'm going about 75-80), switching lanes with me, so I just wanna lose him. I keep it in 5th and punch it. At first I start to loose him at a steady pace... Then he starts falling back faster and faster! Great! He gave up. I look at my RPMs, about 5300 and still at WOT and I look at my boost gauge 17psi and climbing!!! I shut it down and I think it got to about 18psi!

So when I get off the highway, I floor it up to full boost again, I notice that its the normal 11psi until I get into higher RPMs then it starts to climb like a bitch!

Anybody know what could be wrong? I'm thinking my wastegate isn't opening fully... I don't know if that could be a problem with the gate itself or the thing that opens it.


[Modified by KooK, 9:05 AM 11/16/2002]

 

what type of wastegate?

 

Stock wastegate for a 14b

Edit : Sorry, this is pretty much the stock setup sept for the boost controller.. So its a 14b turbo (Crushed BOV so it will hit about 20-22psi before leaking)


[Modified by KooK, 11:54 AM 11/15/2002]

 

is this on a dsm? do you have a 3" downpipe? that would do it.

 

Your friggin kidding me... Besides getting a new downpipe, what can I do to correct it?

And yes... Its a talon

 

what kind of boost controller?

 

Hallman

http://www.taboospeedshop.com

The one second to the bottem...

 

have you ported the o2 housing?

 

You can port the wastegate opening so it can flow more gas.. A bigger turbo would help. somthing with a 7cm2 housing. a 16g for example.. just the turbine side though. The problem is you need to get more gas around the wheel instead of spinning it.

 

overblown - Thanks, I'll look into that!

Internet - Not yet but I've been thinking about it..

 

Oh one other thing.. you can put an external wastegate on.. that would cure all your problems. You could probably have it done for about $275. Hope that all helps.

 

Aaron,

I would check your Boost controller install and also doesn't that car already have a 2.5" downpipe??

Adi

 

Nope, thats a 3in Turbo back exhaust...

 

But anyways like I said check and see if that boost controller was installed correctly...

Adi

 

Overblown is right on the money: the exhaust upgrade is likely at fault. How to fix it? Someone else already suggested porting your internal wastegate passage--this would be a zero cost operation if you've got a few handy tools and some time. Alternately, you could reintroduce some exhaust restriction (install a poor-flowing muffler or some such)... I know this isn't what you want to do but it will solve the problem.

Boost controllers are not to blame in situations like this. On my '88 Shelby CSX-T, I was stupid and installed a complete 3" mandrel system from stock 13c turbo to tailpipe... and now I get nasty creep (over 15 psi) in the upper rev range at WOT. My manual boost controller was set for 10 psi, so I lowered the setting... ALL the way. The result? The boost started much lower (only 4 or 5 psi) but it would still creep at the upper range just like before. The wastegate passage just can not flow enough air to slow the turbine.

Seriously, I'd port the wastegate passage. It's free and it'll fix the problem.

 

Cool!

I guess having an extra wastegate around will come in handy!!

Are there any sites to show me how to port this?

Thanks guys!

 

I don't know of any web page showing how to do this, but it's actually quite easy. (You did say you have an internal wastegate, right?)

Remove the turbo from the car. Take off the wastegate actuator, then remove the downspout. You'll see the wastegate passage; you should also see a clean, clearly-defined circle around it. This circle is where the wastegate flapper contacts the turbine housing when it is fully closed. Using it as a template, hog out the passage a bit (with a die grinder, etc). Be sure to leave some material for the flapper to seal against when the wastegate is shut--I suggest at least a couple of millimeters.

Anyway, then just clean off the shavings (they will blow harmlessly through the turbine blades if necessary) and reassemble everything. Depending on the exact mounting location of your turbo and the shape of the tools at your disposal, you might even be able to do this with the turbo still on the car.

Hope this helps.

 

That is what you need.

 

Oh, well, that could work, too. <chuckle>

 

:-P Hhehehehe.

My bro has a talon. NO boost crep problems. but of course i ported everything with an air grinder.

 

Welp, at least if I screw up I can always have a second chance at this... Thank god I have an extra wastegate

First thing tomorrow I'll see if I can port it.. Hell, I might even polish it up also.

Thanks guys!