View Poll Results: "best" downpipe
HKS
30
24.59%
M2
36
29.51%
Pettit
20
16.39%
Mindtrain
2
1.64%
Other
25
20.49%
Rx7fashion
5
4.10%
N-tech
4
3.28%
Voters: 122. You may not vote on this poll
"best" downpipe
02-13-03, 05:25 PM
#101
Senior Member
Join Date: Jan 2003
Location: Scottsdale, Arizona
Posts: 518
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my experience with M2 DP
[QUOTE]Originally posted by Houdini
[B]OK, maybe I'm not looking at this right, but why do the DPs like the M2 mate up with the turbo manifold with a rectangular flange but with a circular pipe? The exhaust port on the turbo manifold is rectangular. That's like pushing a square peg through a smaller round hole.
I hope my observations are not offending to anyone, but these are my thoughts
You are correct about the M2 down pipe not being a match. I purchased an M2 DP and was astonished not only that I had to spend a couple hours shaping the flange to the turbo exhaust manifold, but the bead of the Mazda metal gasket, were it is suppose to squish, even slightly missed the shape of the M2 factory assembled DP before any shaping was done. In addition to the front flange being less than even close in shape to the turbo exhaust manifold, the back flange was cocked out of square and rotated slightly. Meaning I had to push and twist my stock cat to fit up with the M2 DP back flange. The result was that I got it on there, but found a slight gap at the top side of the mating surfaces between the DP and cat. I had to make shift a tapered gasket to remedy an exhaust leak from this gap. The ultimate disappointment is that now my stock cat back is slightly crooked looking. Not bad, but to remedy this I'll need to remove the cat from the DP and make oval shape holes for the bolts from the cat to slip into as that the flange on the DP is rotated slightly.
I should mention the engine mounts on my car are in perfect condition and there is no notable sagging in the exhaust hangers. Heck the car only had 17,000 miles on it when I put the DP on. The only thing I can think of with the M2 down pipe is they designed it on a car with a broken or squashed right engine mount.
Oh, almost forgot, if you like your entire exhaust rocking back and forth with all it's force on the turbo exhaust manifold the M2 DP does not have the back bracket which would bolt it to the transmission as does the stock pre cat. Without this bracket the entire exhaust system is on rubber hangers other than were it bolts to the turbo exhaust manifold. Talk about lets start cracking stuff. The stock pre cat has a flange and a place for it to bolt secure so the transmission. This makes it and the transmission/engine essentially one solid structure for the rest of the exhaust to bolt to. Needless to say I added a back bracket to the M2 DP to bolt it to the transmission.
Perhaps this all sounds like a hassle, but I am pleased with the outcome of the M2 DP. According to my gtech pro HP meter the DP added mid 20ish HP depending on the air temperature. I should add that I also ground out much of the overhanging welds in the rest of the stock exhaust system.
[B]OK, maybe I'm not looking at this right, but why do the DPs like the M2 mate up with the turbo manifold with a rectangular flange but with a circular pipe? The exhaust port on the turbo manifold is rectangular. That's like pushing a square peg through a smaller round hole.
I hope my observations are not offending to anyone, but these are my thoughts
You are correct about the M2 down pipe not being a match. I purchased an M2 DP and was astonished not only that I had to spend a couple hours shaping the flange to the turbo exhaust manifold, but the bead of the Mazda metal gasket, were it is suppose to squish, even slightly missed the shape of the M2 factory assembled DP before any shaping was done. In addition to the front flange being less than even close in shape to the turbo exhaust manifold, the back flange was cocked out of square and rotated slightly. Meaning I had to push and twist my stock cat to fit up with the M2 DP back flange. The result was that I got it on there, but found a slight gap at the top side of the mating surfaces between the DP and cat. I had to make shift a tapered gasket to remedy an exhaust leak from this gap. The ultimate disappointment is that now my stock cat back is slightly crooked looking. Not bad, but to remedy this I'll need to remove the cat from the DP and make oval shape holes for the bolts from the cat to slip into as that the flange on the DP is rotated slightly.
I should mention the engine mounts on my car are in perfect condition and there is no notable sagging in the exhaust hangers. Heck the car only had 17,000 miles on it when I put the DP on. The only thing I can think of with the M2 down pipe is they designed it on a car with a broken or squashed right engine mount.
Oh, almost forgot, if you like your entire exhaust rocking back and forth with all it's force on the turbo exhaust manifold the M2 DP does not have the back bracket which would bolt it to the transmission as does the stock pre cat. Without this bracket the entire exhaust system is on rubber hangers other than were it bolts to the turbo exhaust manifold. Talk about lets start cracking stuff. The stock pre cat has a flange and a place for it to bolt secure so the transmission. This makes it and the transmission/engine essentially one solid structure for the rest of the exhaust to bolt to. Needless to say I added a back bracket to the M2 DP to bolt it to the transmission.
Perhaps this all sounds like a hassle, but I am pleased with the outcome of the M2 DP. According to my gtech pro HP meter the DP added mid 20ish HP depending on the air temperature. I should add that I also ground out much of the overhanging welds in the rest of the stock exhaust system.
Last edited by greg schroeder; 02-13-03 at 05:32 PM.
12-16-03, 09:19 PM
#103
Boricua
Originally posted by edv
I got the Bonez DP
Someone else installed it for me
As a consequence, I found it quite easy.
I got the Bonez DP
Someone else installed it for me
As a consequence, I found it quite easy.
Hell, I don't even know what kind of DP I have on mine. It definitely has a ceramic coat and it looks nice though.
