How much pipe (length) for a custom exhaust?
I cut a whole and made it exit through the drivers side. Had to buy very little piping and I got my bends done by a local pipe bending shop. I think I got 4 feet and it turned out to be way too much.
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
lets see... turbo back following the stock system looks like:
90° for the outlet (smaller diam + reducer)
90° for the bottom of the downpipe
15° for a kink at the tranny
6-8" of straight from there to the cat
18 inches of straight for the cat
6-8" of straight from there to the kink
another 15° for another kink half way back
6-8" of straight from the kink to the resonator
18 inches of straight for the resonator
a few more straight inches to the diff
about 45° and 8" for the kinks at the diff
90° to exit the diff space
180° U to turn around to go into the muffler
whatever you use for the muffler
and a 90° to exit the muffler
a shiny chrome tip the size of a grapefruit.
I think I used 3x 3" U bends, a 2-1/4 90° for the turbine outlet, a 2-1/4 to 3" reducer, a 3" 90° for the muffler outlet, a 3" cat, 3" "bullet race" resonator, 3" magnaflow muffler, and 3 feet of straight pipe (give or take). plus the tip. there's enough straight on the U bends to fill in the rest of the straight space but extra straight pipe is cheap and easier because it's not squashed from bending.
90° for the outlet (smaller diam + reducer)
90° for the bottom of the downpipe
15° for a kink at the tranny
6-8" of straight from there to the cat
18 inches of straight for the cat
6-8" of straight from there to the kink
another 15° for another kink half way back
6-8" of straight from the kink to the resonator
18 inches of straight for the resonator
a few more straight inches to the diff
about 45° and 8" for the kinks at the diff
90° to exit the diff space
180° U to turn around to go into the muffler
whatever you use for the muffler
and a 90° to exit the muffler
a shiny chrome tip the size of a grapefruit.
I think I used 3x 3" U bends, a 2-1/4 90° for the turbine outlet, a 2-1/4 to 3" reducer, a 3" 90° for the muffler outlet, a 3" cat, 3" "bullet race" resonator, 3" magnaflow muffler, and 3 feet of straight pipe (give or take). plus the tip. there's enough straight on the U bends to fill in the rest of the straight space but extra straight pipe is cheap and easier because it's not squashed from bending.
well i just ordered a 3" catalytic converter, 3" dynomax bullet for a resonator, Summit Turbo muffler, and a mandrel u bend from summit. I will probably just take it to a shop and have them weld it up for me. My current exhaust is 2.5" with just a cat and a glasspack and gets a bit annoying sometimes so im hoping for a little quieter as well as betta flows and maybe better boost control as well. I aint trippin off the flows.
oh i forgot to mention that I am still running a stock size cat which has got to be killing the flow.
oh i forgot to mention that I am still running a stock size cat which has got to be killing the flow.
Last edited by akaryrye; Aug 18, 2007 at 03:44 PM.
www.muscleexhaust.com has great prices on Magnaflow stuff which is usually very quiet.
Also, I bought a 5' section of straight, 3 or 4 90's, and I think a couple of 45's. All those gave me enough pipe and some leftover.
Considering the car has been boosted and running for a few months now, the how much pipe for an exhaust is (for me) a mute point.....
However for interest sake, a mate of mine who does good steel work put this little system together for me.....

It's sitting very low in this pic, and has (long) since been reworked to sit higher, and the join has been brought back to right before the 90 deg bend into the muffler.
However for interest sake, a mate of mine who does good steel work put this little system together for me.....


It's sitting very low in this pic, and has (long) since been reworked to sit higher, and the join has been brought back to right before the 90 deg bend into the muffler.
J-bend = 180* U bend? Or is it different?
Did you have to bend the 5' length at all or just run it from the cat to half the J-bend, into muffler, and then use the rest of the J-bend to route from muffler to exit?
Did you have to bend the 5' length at all or just run it from the cat to half the J-bend, into muffler, and then use the rest of the J-bend to route from muffler to exit?
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
those estimates sound about right.
though if you want to save some coin, you dont need stainless pipe beyond the dp. it's nice, but aluminized will last a long time.
I recommend the magnaflow universal stainless (polished or brushed) in 4x9" by as long as you can fit. I have the 5x11x22 and it's real nice. and long.
though if you want to save some coin, you dont need stainless pipe beyond the dp. it's nice, but aluminized will last a long time.
I recommend the magnaflow universal stainless (polished or brushed) in 4x9" by as long as you can fit. I have the 5x11x22 and it's real nice. and long.







OVERKILL

