SGOGT4

I know many people mention that when your waste gate isn't functioning properly you can get overboost, but is it possible that the waste gate can leak or be week? I am only getting about .9 bars with my 1 bar spring. We have been checking for leaks on the pressue side of the turbo but haven't found anything.

What typically are the symptoms of a failing waste gate?

Thanks!

PorschePhD

Yes, it can bleed from the guide in the housing. You can tell by blowing air into the port. If the air comes out before the valve starts to lift then the guide is letting air out before the valve can move.

Maroun

Just changed my waste gate about 6 months ago. I was overboosting 2bars! Not too sure why now it is 1.3 bars. Shouldn't it be at 0.9 bars? Problems with the springs?

Sameer

I have been using the Tial 46mm wastegate got the past 4 yrs with no issues at all. I think they used it in the Porsche 962 race cars.

BrianKeithSmith

Sameer: It doesn't matter what kind of wastegate you have or what car it was used on, if its not hooked up right, or isn't working right, is brokem, etc.

Maroun:
What size spring do you have?
Is your car still running after hitting 2 bar? If so, your engine must be incredible!!!

Brian

Sameer

Brian,
You absolutely correct. I was just suggesting the Tial wastegate as an alternative to the stock if one were to change.

SGOGT4

Is there any reason that a 1 bar spring shouldn't be showing 1 bar of boost on a secondary VDO boost gauge? I am seeing .9 but not 1 bar.

A930Rocket

What kind of WG do you have?

With a Tial, you have run a spring less than you want if you are using aftermarket headers. For example, if you have GHL headers, you run a .8 spring to get 1 bar. The aftermarket headers are more effecient.

If it's stock, try what Stephen said. You may also be losing boost somewhere else in system, i.e. your O-rings, etc.

pete77930

I know first hand that GHL headers have too small of a diameter for the wastegate pipe. I would run a .7 spring in my tial and by 3rd gear i was getting boost creep to 1.3bar. i hacked off the old wastegate pipe and had a shorter length, larger diameter one welded in its place. I now run 1.2 bar in all 4 gears with no creep.

Sameer

With my Tial 46mm WG and B&B headers and with 0.9 bar spring, I get rock solid at 0.9 bar with slight fluctuations to closer to 1 bar under full load and on a cool day.

jwl

Got a waste gate question. I check my stock gate by using a 0-25 psi gauge and it just starts to open at 15 psi and fully opens at 18 psi. I check the spring and it appears to be after market but I have no idea what it's rated for. Is the spring to strong?