Test pipe question
Test pipe is used for removing the cat. Why would we want to do this? On a N/A car, a cat isn't a big restriction at all in the exhaust. Removing usually results in a couple of WHP, but nothing big.
On a turbo car, the cat is a HUGE restriction. Removing the factory one and going to a test pipe will gain anywhere between 10-30 WHP depending on a few things. For a cheap, flanged piece of pipe, that's amazing value for power. My test pipe is resonated, so it is a bit quieter <3K RPMs, but it is VERY loud at WOT. You'll get an increase in boost too with any test pipe. On my car with only a Megan TBE, I went from 19.5 PSI on the gauge to 21 PSI after install. I turned it back after I installed an MBC.
[Side story: I had a friend drive around the neighbourhood in my car while I listened outside. I could hear every pull he did, some 1/4 to 1/2 mile away. Having a test pipe makes me drive slower because I know how loud it is outside. In the cabin, it doesn't sound much louder than just a catback.]
I highly suggest getting a test pipe if you want the most power from the exhaust.
Be warned! They aren't exactly legal, it will trip a CEL if you don't space out the rear O2 sensor with a 1/2" drilled 18mm non-fouler, and now my car smells like a go-kart. I've had police follow right behind me without any problems, but anyone can definitely smell it. You can PM me if you have any questions.
On a turbo car, the cat is a HUGE restriction. Removing the factory one and going to a test pipe will gain anywhere between 10-30 WHP depending on a few things. For a cheap, flanged piece of pipe, that's amazing value for power. My test pipe is resonated, so it is a bit quieter <3K RPMs, but it is VERY loud at WOT. You'll get an increase in boost too with any test pipe. On my car with only a Megan TBE, I went from 19.5 PSI on the gauge to 21 PSI after install. I turned it back after I installed an MBC.
[Side story: I had a friend drive around the neighbourhood in my car while I listened outside. I could hear every pull he did, some 1/4 to 1/2 mile away. Having a test pipe makes me drive slower because I know how loud it is outside. In the cabin, it doesn't sound much louder than just a catback.]
I highly suggest getting a test pipe if you want the most power from the exhaust.
Be warned! They aren't exactly legal, it will trip a CEL if you don't space out the rear O2 sensor with a 1/2" drilled 18mm non-fouler, and now my car smells like a go-kart. I've had police follow right behind me without any problems, but anyone can definitely smell it. You can PM me if you have any questions.I've had a cop sit behind my EVO at a redlight for a couple minutes before he pulled me over for a "loud exhaust"
He didnt mention anything "smelly"
I just remember following behind my buddies who run test pipes on the street and it is quite noticable. None of us have ever gotten tickets for it though.
Evolving Member
Joined: May 2007
Posts: 123
Likes: 0
From: Sacramento
It seems like the best HFC out there, power wise, is the Mil.Spec 100 cell HFC. A tuner here dyno'ed a car that switched from a testpipe to the Mil.Spec HFC and only lost ~ 5WHP and WTQ. If I ever wanted to go HFC, Mil.Spec would be my first choice.
I think for stealth reasons though, you would need to weld a VIII's cat heat shield on it because the Mil.Spec HFC only has a bulge in the pipe. Not very stealth looking.
You could always go with a RRE rally cat. It looks like a cat, but its really a testpipe under the heatshield. Super stealth, and provides great gains at the same time. The best of BOTH worlds!
I think for stealth reasons though, you would need to weld a VIII's cat heat shield on it because the Mil.Spec HFC only has a bulge in the pipe. Not very stealth looking.
You could always go with a RRE rally cat. It looks like a cat, but its really a testpipe under the heatshield. Super stealth, and provides great gains at the same time. The best of BOTH worlds!
Last edited by MaxKanisha; Dec 15, 2008 at 01:01 PM.
Evolving Member
Joined: Oct 2007
Posts: 336
Likes: 0
From: Plano, Texas
It's a TESTPIPE or NOTHING for me.........I love my car being louder and I love feeling the extra raw power. Almost everyone hates me for it, but I don't care because an Evo sounds so damn good with a test pipe/straight exhaust with no restrictions whatsoever.
what type of testpipe do you guys recommend?? I am goign to ge t teh EPM 02 dump, and the megan racing 3 inch d/p. But what testpipe should i get, because im gunna get an exhaust cutout possibly, so all i will ened is the testpipe now.
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evoluXrichie
Evo X Engine / Turbo / Drivetrain
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Mar 14, 2009 03:30 AM
