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TurboKraft TurboKraft is offline
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Join Date: Mar 2005
Location: Phoenix, AZ
Posts: 2,757
Originally Posted by sundevil64 View Post
Which Magnaflow is that? I hope there is some support on that muffler.

Of course there's a support!

That's a shorty canister for that RS-styled car. Even with the twin 3" pipes out the back, it wasn't that noisy, just fine in the cockpit.

There are larger 3"/3" all-stainless muffler canisters, and all a rather quiet. Pick the largest oval that will fit in your space:
MagnaFlow Exhaust Products - For Trucks, Suv's, American Muscle, Diesel, & Sport Compact Vehicles
We use frequently them for our in-house builds and they pass db on track. No resonance, still lets the engine make all the good classic 911 engine sounds -- tenor exhaust note, mechanical valve train, whistle and whir of the turbocharger, etc.

If your sound measurement is like at one of our local tracks, it's at WOT -- so the wastegate is wide open, too, and that's very loud. Choices are to:
- plumb the wastegate's exhaust back into the muffler
- try to do some mini muffler off the wastegate without introducing boost creep.
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.
Chris Carroll
TurboKraft, Inc.
Tel. 480.969.0911
email: -
Old 05-20-2013, 11:43 AM
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