My exhaust setup

[Seymour Butts]

So I finally got my obx header from a dude on ebay $90 no dp, and Im puttin the whole thing together first week in June. I wanna go no cats, 2.5", straight though muffler... think thats how I can get the most horses...

basically Im after torque, my auto has none. any opinions on this setup? is this the best way to get the most power? not worried about cel or emissions, my big prob is its gonna be damn loud...

[Mahonroy]

I am thinking that its gonna be damn loud! lol, you may consider putting in a resonator into your equation there, you won't loose too much power, and I mean if you think about going from a POS exhaust manifold, 2 non high flow catalitic converters, a resonator, and a muffler, AND small diameter tubing, to a header, a resonator, and a high flow muffler, with high diameter tubing, that is a big improvement, and a resonator won't hurt your power too much. Just what I think might help :D

[XDGT03]

I think without any cats, you may want to go with 2.25 instead of 2.5 Reason being that you may have a serious deficiency in back pressure. I don't think that a resonator and muffler will do it for 2.5 pipe, plus way to far down stream.

To keep the sound down you probably cannot not go with a straight through muffler design. Even with a resonator.

I have header, 2.25, 1 cat. I have had dynamax muffler no res (bee buzz), dynamax and resonator (best for deep sound, no bee buzz), 10" glasspack w/ duals out sides infront of rear tires (loud as ****).

[carbonman]

Torque you say?

[Seymour Butts]

Torque you say?

:D

i love tork!

I'll definetley think about magnaflow hiflo cat and resonator... you think 2.5 is a bad idea? hmmm... well I dont know alot about this stuff so I'll take advice, thanks fellas

[Boostin_GT]

if you want torque..2.5 is not a good idea...basically..you're losing your low end...

[labmixz]

if you want torque..2.5 is not a good idea...basically..you're losing your low end...

well, you will loose your low end, but you'll gain some nice high end... I got a 3" exhaust on my betaII and my high end is... well... sick... and I don't have headers yet...

(if your wondering why the 3", it's for F/I which isn't ready yet)

[Josh K]

Yeah, I wouldn't go with that much pipe diameter if you're taking out the cats.

High end horsepower is useless if it takes forever to get to it...

[jjos1]

I have a custom 2.5" cat back no res that I had on my 01 man I felt that I lost low end but gained top end, I then put this system on my 04 (a auto) although a different motor than the 01 I still lost low end. As for loudness my setup was not loud at all

[tharptroy]

I think you'd be going too large in diameter

[evil247]

I have 2.5 piping, resonator, 2nd cat and the fastest NA slip on the board.

[Seymour Butts]

good point hmm... but I spose for u Its somewhat different, dont u have manual evil? I dont know whats best for auto, Ive never had one before this car.

[evil247]

not sure about the auto as I do have a manual. Keep in mind that I also have crush bent piping the reason I went with the 2.5 was to keep the bends at least 2.25. If you are getting mandrel bent then 2.25 should be fine. When the car was closer to stock we ran the GLS and the GT hatch down the track and were within .01 seconds of each other(they had the same mods, I think the GLS might have had a short throw). The gls had 2.25 crush bent and the GT had 2.5 crush bent. Hatch weighs a little more.

[XDGT03]

evil, what muffler do you have?

[evil247]

It's an AC Autotechnic Carbon Fiber muffler

[Josh K]

I have 2.5 piping, resonator, 2nd cat and the fastest NA slip on the board.

Well you're making up for the torque loss with the resonator and cat ;0)