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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,289
Hi Chris, when you said "The factory 1986-89 930 wastegate outlet pipe can cause boost creep, especially on engines with aftermarket headers where the WG path off the collector is not optimal."
Do you mean the seperate little factory wastegate muffler made by Bischoff?

My '87 turbo has one of those and I'm not sure if it was origonal or a previous owner put it on there when they put on the B&B headers.

My car has 964 cams and B&B headers and single out left side muffler.
Ever since I gutted all the baffles out of that muffler and hogged out where it necks down to 2.5" inside of it to 3" to lower it's backpressure I've had some boost creep at high rpms.
It didn't get much louder and sounds very nice without all the baffles. I left the approximately 1" of stainless steel packing around the inside diameter intact.

I've thought of doing something to that wastegate muffler to reduce it's backpressure and see if I had less boost creep but havn't tried it yet.

thanks for any info on this.
Old 05-20-2013, 11:02 AM
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