3” dual exhaust on 330 high compression?
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Joined: Oct 2019
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From: NJ
3” dual exhaust on 330 high compression?
Any running 3” dual exhaust with the 330?
I have Thornton dual exhaust manifolds. Converting single to dual.
Would I be loosing too much back pressure with 3”?
I have Thornton dual exhaust manifolds. Converting single to dual.
Would I be loosing too much back pressure with 3”?
Last edited by Drews67Cutlass; May 2, 2020 at 07:04 AM.
Old(s) Fart
Joined: Mar 2007
Posts: 50,815
From: Northern VA
There is no such thing as too little back pressure. That's another urban myth that will never die. The reality is that 3" pipes for that size motor are a waste unless you plan to spin it to 7 grand or so. Using 3" pipes with cast manifolds is a joke. Save yourself a lot of fitment headaches and just go with 2.5".
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Joined: Nov 2008
Posts: 8,496
From: Central Fl
I’m not even sure I go with 2 1/2 for a 330, more like 2 1/4.
The first time I went from manifolds to headers and dual exhaust on my car, which is a mildly modified 350, I went with 2 1/4 pipes all the way back. I later changed the mufflers etc. and went with 2 1/2 all the way back. I didn’t notice any real difference. And I was running EFI, my fuel map didn’t change much either.
The first time I went from manifolds to headers and dual exhaust on my car, which is a mildly modified 350, I went with 2 1/4 pipes all the way back. I later changed the mufflers etc. and went with 2 1/2 all the way back. I didn’t notice any real difference. And I was running EFI, my fuel map didn’t change much either.
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