Do any of you vendors have plans of making a 2.5 in test pipe for those of us who plan on retaining the stock exhaust or a JDM exhaust that is 2.5 in in diameter? For flow and power, maintaining constant diameter will always net the best results, and even though a 3 in test pipe makes power on a stock exhaust, a 2.5 should make more. So, can anyone help me?

 

My god, an entire day has gone by and no one has responded? I know for a fact that I am not the only one who is looking for this, and why no vendor has made one for the X yet is beyond me. These are readily available for the 8/9, and for the same reason that I am looking for one for my X. Vendors, please speak up.

 

I don't think there is one available yet, you would have to get one custom made.

 

Why are you concerned with using a 3" test pipe reduced at both ends with the proper flange to fit correctly?

 

you try ultimate racing?

 

dont get your panties up in a bunch, if noone responded, it means that no one cares

 

Read the first post to get your answer. In short, although a 3 in will make gains, maintaining constant diameter will net better velocity and less turbulence and thus more power.

 

HKS metal catalyzer 60mm-65mm

http://www.hks-power.co.jp/products/...3005am003.html

 

^A test pipe makes way more power than any high flow cat, dyno proven. High flow cats barely make any more power over the stock cat and aren't really worthwhile mods. Thanks for trying to help, though.

 

while i agree that test will get you most power over stock cat, i dont buy the high flow cat mod is worthless, do you have any data that shows no or negligible gains from hfc over stock cat, specifically in X?

thanks

 

If you don't care about the environment, go catless. High-flow cats will result in an improvement over OEM. The gains depend on how restrictive the OEM unit is. A complete three-inch exhaust from the turbo back with a high flow cat will yield more WHP than just putting in a test pipe on the stock system. On Subies, the difference between catless and high-flow cats are marginal enough, it was better for the environment to look for gains elsewhere.

This article on a test with Honda found the high-flow cat yielded 5whp and the test pipe didn't perform that much better.

http://www.importtuner.com/tech/impp...ers/index.html

 

^Dude, I had an STi with a Turbo XS turbo back (the one with the 4 in downpipe) with a high flow cat, and swapped it with a test pipe and picked up 10 whp instantly. I don't call that marginal. Second, obviously a complete turbo back with a high flow cat will make more power than putting a test pipe on a stock exhaust, but that was never in question. Fact is that a test pipe on a stock exhaust will pick up about 10 whp, which is almost half of what a full turbo back will gain and it costs far less while still keeping the car quiet.

Lastly, of course a test pipe on a little NA honda motor makes negligable gains over a high flow cat, but it's a very different story when we are talking about a turbo car like the EVO. Not trying to be ugly, but with the exception of your comment about the environment, pretty much everything you said was incorrect. Do some more research on the subject, and I think you'll find that there is much for you to learn.

 

You don't know what you're talking about. A catted downpipe vs. a catless downpipe on a Subaru doesn't yield marginal results. It's a big a deal, especially once you get into aftermarket turbos and start turning up the wick. Sometimes, it's ok to NOT post. I too came from a Subaru that made some solid power and a downpipe with a catalyst is the anti-Christ if you will if you're serious about making power. Back on topic....

 

^If you read my post above yours, I said the exact same thing. That's one thing that forums are never short of is noobs. Oh well...

 

FAIL