Has anyone made their own Test Pipe?

[drledford93]

After reading and getting excited about a do-it-yourself CAI, I started thinking about the possibilities...

There's a local exaust place that has made several cat-back exaust straight pipes for other turbo cars and have done well with them. What I'm curious about is if anyone has made (themselves or instructed a shop to make) a test pipe to replace the cat after the downpipe? Does anyone know the angle at which it needs to be bent? Where it does? Length? (No, I haven't had time to get under the car and measure at all yet.)

I've considered just hollowing out the existing cat, but wasn't sure of the effectiveness of it versus a 3" pipe. Has anyone tried any of this? BTW, removal of cats is not a concern, as there are no pollution restrictions here.

Daniel

[speed3shon]

use the same size pipe you plan to have the rest of the exhaust being.

if you plan to eventually have a full 3" exhaust, use a 3" pipe, if not, stick with just a 2.5" pipe.

[clos561]

you cna just hit all the stuff out of the cat from what i hear, a few have done it without any problems and its free

[drledford93]

That's what I'm wondering about...I want to hear from people that have done it before I go and do it... (no)

Daniel

[Falconx84]

i wouldn't bust the cat..... screws up air flow, fluid dynamics, all that jazz

there was a guy on this forum or the other.... He had a shop cut out the cat and weld in a straight pipe. ran like $80 or so. But for that price diff, may as well spend and extra $50-60 and replace the whole thing so you have something to swap in for dealer/emissions visits

[numbnuts22715]

i wouldn't bust the cat..... screws up air flow, fluid dynamics, all that jazz

there was a guy on this forum or the other.... He had a shop cut out the cat and weld in a straight pipe. ran like $80 or so. But for that price diff, may as well spend and extra $50-60 and replace the whole thing so you have something to swap in for dealer/emissions visits


you can get used ones for even cheaper than that.. Ive seen a few used turboxs pipes for 100. I know some people have a few issues with them, but itd be worth it if you wanna save money.

[driver311]

I built my own. took an hour. 10whp dyno proven.

[rodney]

i gutted my cat and no problems what so ever

[killerMS3]

Yeah, this was really easy. it took me about 2 hours to do, including removal and install. the welding was easy as pie, because i used the seams on the cat and the lines on the pipe to orient the flanges. they were dead on when i installed the pipe. i used 2.5" pipe from autozone, $7.99. Money and time well spent. I like the gains.

http://i148.photobucket.com/albums/s24/paddedwallz85/Mazdaspeed%203%20GT/DIY%20race%20pipe/12-12-07_1949.jpg

http://i148.photobucket.com/albums/s24/paddedwallz85/Mazdaspeed%203%20GT/DIY%20race%20pipe/12-12-07_2019.jpg

http://i148.photobucket.com/albums/s24/paddedwallz85/Mazdaspeed%203%20GT/DIY%20race%20pipe/12-12-07_1222.jpg

[clos561]

i gutted my cat, lower tone and im sure there is increased performance

[rodney]

Yeah, this was really easy. it took me about 2 hours to do, including removal and install. the welding was easy as pie, because i used the seams on the cat and the lines on the pipe to orient the flanges. they were dead on when i installed the pipe. i used 2.5" pipe from autozone, $7.99. Money and time well spent. I like the gains.

http://i148.photobucket.com/albums/s24/paddedwallz85/Mazdaspeed%203%20GT/DIY%20race%20pipe/12-12-07_1949.jpg

http://i148.photobucket.com/albums/s24/paddedwallz85/Mazdaspeed%203%20GT/DIY%20race%20pipe/12-12-07_2019.jpg

http://i148.photobucket.com/albums/s24/paddedwallz85/Mazdaspeed%203%20GT/DIY%20race%20pipe/12-12-07_1222.jpg

nice job on the test pipe

[aaronc7]

i wouldn't bust the cat..... screws up air flow, fluid dynamics, all that jazz

there was a guy on this forum or the other.... He had a shop cut out the cat and weld in a straight pipe. ran like $80 or so. But for that price diff, may as well spend and extra $50-60 and replace the whole thing so you have something to swap in for dealer/emissions visits

80 sounds pretty high, I got a resonator cut out of my old civic and it ran me $30....this is like a small family owned muffler shop so maybe they are just cheaper. I'm sure the piping was smaller but I doubt it would make that much of a difference.

[Falconx84]

i have no clue where the guy was from, in the city or cali I'm sure it costs more. Plus since most shops are under the impression that it's "illegal" they may have charged more, lol

a lot of your smaller shops don't realize that there's a cat in the DP so they act as if they're removing everything so some shops will actually refuse to do it

[mazdaspeedjay]

yes i've posted a thread about this i make them for $40 you just have to send me your stock unit so i can modify it.

[MSLou]

i had two resonators and a cat removed for $60