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fredmeister fredmeister is offline
Smart quod bastardus
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Join Date: Oct 2002
Location: Baltimore, MD, USA
Posts: 2,235
You are not alone apparently with this issue. In your case its extreme it sounds.

Perhaps the diapragm is not sealing on the housing lip or its split somewhere that exascerbates your leak. Check this out.

I think the guide to valve clearance is one number I would like to get consensus member responded to me with the info but I cannot find it right now.

Anyway, the guide can be replaced with a new machined guide and pressed into the housing.
I think its worth looking into to keep the stock wastegate from Porsche because it is such a good unit. Or buy a Tial like lots of other members keep pounding on. Depends upon your personal taste and if its cheaper to fix the OEM or buy new I guess.....
I like the stock OEM wastegate and I have modified them for myself and another forum member to make it adjustable, Of course it has to be in good working order and the bushing not leaking appreciably for my mods to work correctly, but it is possible to get the valve guide machined by a good machine shop. I just wish I had a drawing of the proper guide dimensions to get this done.....hard to get any info on this anywhere.

1979 930 Turbo....3.4L, 7.5to1 comp, SC cams, B&B intercooler, Snow Perf water/meth injection, Rarlyl8 headers, Garret GTX turbo, 36mm ported intakes, Innovate Auxbox/LM-1, custom Manually Adjustable wastegate housing (0.8-1.1bar),--running 0.7bar max
---"When you're racing it's life! Anything else either before or after, is just waiting"
Old 05-31-2013, 10:36 AM
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