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911nut 911nut is offline
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Join Date: May 2001
Location: Michigan
Posts: 2,511
When I say boost onset, I mean just that; when does the turbo begin to deliver boost. So at 2500 rpm I'm developing 3 psi of boost. I'm running the K27-7200 turbo that came with the car and the Rarlyl8 muffler I installed last fall.
With the stock heat exchangers, j-pipe and Rarlyl8 muffler boost onset was 3000 rpm; with a full stock set-up it was 3400 rpm.
I know it doesn't sound like a big deal but that 3 psi is adding some power that can be felt. Previously there would be nothing much happening at that rpm; just the feel of 3.3 L at 7:1 cr and we all know what a thrill that is
As for the cat and stock muffler, they weigh 25 lb. each. My Rarlyl8 muffler and tailpiece weigh 10 lb. so there was a net savings of 40 lb. before I added the headers.
Paul B.
'91 964 Turbo
Port matched, SC cams, K27/K29 turbo, Roush Performance custom headers w/Tial MV-S dual wastegates, Rarlyl8 muffler, LWFW, GT2 clutch & PP, BL wur, factory RS shifter, RS mounts, FVD timing mod, Big Reds, - 210 lb
Old 04-28-2009, 01:52 PM
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