T.O_Camaro
12-10-2002, 07:19 PM
My plan is to run straight from my headers 3" pipes connected to Flowmaster 40 Series Mufflers and before the mufflers the outer casing of cats wenlding surving no purpose but a look to fool cops if ever stopped and after the mufflers continue the 3" piping curving towards the outside coming out before the rear tires. I should save about 2 feet each piping and I'm wondering how much performance I could achieve with this and how much noise i should expect coming from this set up?
Distortion28
12-10-2002, 11:06 PM
if your header primaries are big 3 inch piping all the way back is loud as hell. My friend has it on his mustang and it gets annoying after a certain point. I'd go with 2.5" piping, and weld in exhaust cutouts, that way when ur at a show or something when you really wana be loud un cap em
dust6928
12-11-2002, 03:26 AM
if i remember correctly, i read somewhere that a single 3" exhaust can flow enough air for up to a 450hp motor. so 2 2.5" pipes should be good for wuite a bit more than that
OldSStroker
12-11-2002, 08:06 AM
Originally posted by T.O_Camaro
My plan is to run straight from my headers 3" pipes connected to Flowmaster 40 Series Mufflers and before the mufflers the outer casing of cats wenlding surving no purpose but a look to fool cops if ever stopped and after the mufflers continue the 3" piping curving towards the outside coming out before the rear tires. I should save about 2 feet each piping and I'm wondering how much performance I could achieve with this and how much noise i should expect coming from this set up?
The mufflers will be the choke point in your system. Carrying the 3 in pipes back to true 3 inch inside diameter straight through mufflers like Dynomax Ultraflow Welded should make more RWHP than the Flowmasters.
Mufflers not only surpress noise, they take heat out of the exhaust stream; maybe 300*F or so at high power. The cooler exhaust has a lower flow, so smaller pipes after the muffler don't hurt much. A smooth transition from 3 into 2.5 inch after the muffler should work.
As pointed out, 3 inch pipes can be noisy, especially if you dump them sideways ahead of the rear wheels. Carrying two mandrel-bent 2.5 in. pipes over the axle won't hurt much at all.
Remember, the muffler is the big restriction. Make sure it's a high flow one (or 2).
Unless you plan to use your cats as Terminator Boxes, run a pipe straight thru them.