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dean dean is offline
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Join Date: Dec 2001
Location: MA USA
Posts: 2,938
Re: 930 Wastegate Question

Originally posted by johnman001
I rigged up a regulator and a gauge and applied pressure to the line.

At .8 bar (12-13psi) the valve seems to remain closed. At 1.1 bar the valve can be heard to open and close, but a hissing sound can be heard as air is escaping somewhere.

The car always used to run about .8 bar until now.

My main questions are:

1.) Is the diaphragm supposed to hold pressure, or do the y leak slightly?

2.) If I buy a replacement diaphragm from Lindsey Racing, where would I get a new gasket for the wastegate body?

3.) Would a leaking diaphragm be a cause for this overboost condition?

4.) I have seen the TiAL wastegates and believe one of them to be a direct replacement for mine, but I would rather attempt rebuilding mine than spending the extra money right now on a wastegate. (I did read that a rebuilt wastegate may be short lived, but I still want to try).

5.) Are there any other sources for a gasket and the diaphragm?

Thanks for your help/advice. I may try giving Imagine Auto a try since they are local to me.

Did you hook the regulator to the control line for the wastegate? There is a vent also.

The diaphram isn't supposed to leak. However the valve guide will leak some and that is ok. A leaky diaphram will cause an overboost cond.

Imagine auto has the diaphram.
911 SC turbo, 3.0L 930 motor, G50, 930 brakes, DTA EFI, 352 RWHP DynoDynamic dyno,
Old 07-22-2007, 05:30 AM
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