D's Up.

VIDEO:
* http://www.youtube.com/watch?v=-E_ki...el_video_title

CLIFFS:
* Will a 70mm test pipe get rid of some of the drone and rasp of my 3" single exhaust? I have a seller that has both a 63mm test pipe and a 70mm test pipe. I'm planning on getting the 70mm IF it will get rid of some of the drone and the rasp.

Full story:
Hey guys my AP1's stock cat has been bad for some time now (causing an exhaust leak and the internals are loose) and I'm just now getting around to buying a test pipe. I have a 3" exhaust sitting in my garage and I'm currently running the OEM exhaust. Now my question is, will a test pipe substantially lower the drone and rasp compared to my current set-up (3in cat-back + bad cat)? If it will, then I plan on buying the 70mm TP. If not, I'll just keep my OEM exhaust on and buy the 63mm TP. Please help as I am planning on picking up one of the test pipe's asap.

Thanks in advance,
- David.

FluKy15

More rasp (but not bad trust me) but will lower your drone.

D's Up.

Will it deepen the tone of my exhaust at all?

FluKy15

Most likely, but I dont know which exhaust you have, you didnt post it. I would describe the addition of a test pipe as making the exhaust sound pure.

D's Up.

It's custom made, my bad. It's a 2.75" straight pipe from the cat-back to a wicked flow muffler.

D's Up.

Well I ended up buying both the 63mm and the 70mm test pipe X) lol. I threw on the 63mm with my stock exhaust and let me just say that it is a night and day difference compared to my broken OEM cat. The car finally drives how it should! I'll try out my single with 63mm tomorrow and depending on how that goes, the 70mm as well.

JBAutosports

I would suggest leaving it at 63mm. You want an even flow of exhaust - mismatched piping can cause some turbulence. If you are running stock exhaust and exhaust manifold, the 63mm test pipe should be adequete!

D's Up.

Well I'm rocking the 63mm test pipe and my single exhaust right now and I have to say that my exhaust is WAY louder under acceleration now, especially above 6k. It also noticeably lowered the drone but it's caused this nasty rasp when I get off the throttle above 4k rpm. If I throw on the bigger (70mm) test pipe, will that help with the rasp?

My dilemma is that my single exhaust's piping is bigger than 63mm but not quite the size of the 70mm test pipe. So should I run a pipe that's a little bit smaller or a pipe that's a little bit bigger?

D's Up.

Well I threw on the 70mm test pipe and let me just that it didn't help at all! In fact, I think it sounds a little worse in terms of raspiness and it feels less powerful (butt dyno). I'll be putting it up for sale soon.

No matter what I do, I can't seem to get rid of that excessive rasp. It's crazy annoying, makes the whole car look/sound cheap. So I'll be going back to the OEM exhaust + a 63mm test pipe till I figure out what to do with myself in the future.. lol. I'm probably just gonna' drive it like that till I can pick up a CTSC and then mod the exhaust and so forth.