pipe size question
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pipe size question
This isn't 3rd gen specific but the priciples will apply. I have an 87 TBI truck (LO3 equivalent). the muffler fell off the other day so it's time for an exhaust. I am going to change to a true dual exhaust and I want to know if a dual 2.25" will allow enough flow for the 330HO crate motor I want to install later. For now I will be running the stock manifolds (I know get headers, I wish I could but I have twins due very soon) so I think the 2.25" will be the best bet for now. I did price dual 2.5" but I'm afraid I won't keep enough flow velocity with that big a pipe on the puny 305.
What do you guys think? I'm getting the exhaust done on Thur so I have to decide by then.
What do you guys think? I'm getting the exhaust done on Thur so I have to decide by then.
Last edited by jagone; 04-01-2003 at 09:59 AM.
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Car: 99 Formula
Engine: LS1
Transmission: T56
Axle/Gears: 342
I forget the exact figures, someone posted a chart awhile back with the specifics.
But since dual 2.25'' is nearly equivalent to single 3''. I would say unless that crate motor will push out more than 400 hp, you'll be fine with 2.25 duals.
But since dual 2.25'' is nearly equivalent to single 3''. I would say unless that crate motor will push out more than 400 hp, you'll be fine with 2.25 duals.
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Thanks Mark, I know Dynomax has a hp to pipe size chart, but I thought their requirements were a little large.
I'm not looking for the crate motor to ever see 400hp in the truck, If anything I was probably going to end up "de-tuning" it a little by installing the LT4 prod cam so I can eliminate the requirement of my EGR valve and have a roller cam.
I'm not looking for the crate motor to ever see 400hp in the truck, If anything I was probably going to end up "de-tuning" it a little by installing the LT4 prod cam so I can eliminate the requirement of my EGR valve and have a roller cam.
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Car: '88 Camaro
Engine: 355
Transmission: 700R4
well, id say dual 2.5" wouldnt hurt too much for the time being, and heres a portion of a flowmaster chart
suggested pipe sizes for street performance
300-350 ci- single 3" or dual 2.25" for 250 hp
single 3" or dual 2.5" for 300 hp
350-450 ci- single 3" or dual 2.5" for 300 hp
single 3.5" or dual 2.5" for 350 hp
single 4" or dual 3" for 400 hp
suggested pipe sizes for street performance
300-350 ci- single 3" or dual 2.25" for 250 hp
single 3" or dual 2.5" for 300 hp
350-450 ci- single 3" or dual 2.5" for 300 hp
single 3.5" or dual 2.5" for 350 hp
single 4" or dual 3" for 400 hp
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