Hey guys,
Recently did catback exhaust, but looking into high flow cat or test pipe. Any RA owners used a high flow cat or test pipe? Any horse gains, sound difference? Let me know what you think I should go with. I am leaning more towards high flow cat, but not sure if it would really make that much of a difference.

 

Even though some people argue that you replace your cat with a high flow cat you just replace it with a another restrictive pipe. With a test pipe you remove the restriction altogether.

For me, I used to always went the test pipe route before. Now, I can't live with the fumes that go along with the test pipe.

I opted for the hi flow cat this time and I get low fumes with a little HP to gain and a little increase in noise. I do pay almost 4x as much as a test pipe too. Plus the stock cat isn't that bad of restriction in the first place either...

If you can live with the fumes and increased noise getting a test pipe will give you the most HP for the $.

 

You only notice the fumes when coming to a stop.

There is about a 7 HP gain by going with a straight pipe.

 

There was a thread awhile back with some evidence (dyno charts I think) that a high quality high flow cat wasn't much worse power-wise than a test pipe.

-Taranis

 

Of course you will notice fumes coming to a stop. haha.
People will tell you your car stinks though.

 

If you want to stay legal, lose a few whp and have a slightly quieter exhaust go for a high flow cat.
If you don't care or if your local authorities don't care, want a little more power and a roaring exhaust get a test pipe
Good luck with your decision!

PS. I went testpipe and it's pretty loud.

 

I used to have a Scion TC that I had a turbo installed with only a test pipe and I hated the smell. Also, every time I got out of the car my clothes would still smell like the exhaust, and chicks don't dig that! I would never go that route again for a miniscule amount of horsepower gains that you probably won't even notice.

 

I have the UR test pipe and couldn't be happier except for the CEL that goes along with it. I don't know what people are always complaining about fumes for. Yea you can smell it when coming to a stop but I have never had it smell so bad that I would feel the need to change it for something else. Some of you guys on here make it sound like you have a hose hooked to the exhaust pipe and route it into the car that it's so bad you can't breathe.

 

I went with UR's mini muffler pipe, it should be less restrictive than a high flow cat I would assume, still found it loud, thats why i installed 2 resonators inline to tame it down

 

I went with the test pipe, but on my RA its loud, my entire exhaust is 3". I dont often drive in sport mode cause of how loud the car is. The orange on mine is very hard to keep clean with all the soot. Im a mechanic and always smell of gas and oil, plus my girl kinda likes it so it works both ways. like they say boost gets you laid haha

 

Did you guys leave the stock exhaust on? or is it loud because of aftermarket axle-back section with the addition of test pipe/testpipe with mini-muffler?

 

Just FYI: High-flow cats are NOT legal replacements for the OEM cat.

 

I have stock exhaust from my cat back. It's louder than stock but barely.

 

I know Cali everything is almost all aftermarket is illegal. Here in NJ we just need a visual test. The funny thing is the high flow cat from AMS doesn't even look like a cat more like a resonator, but I know it doesn't smell that bad.

 

It is not a California law; it is a federal law, a violation of the Clean Air Act. Though, typically, it is only enforced on the state level. Here is a link:

http://autoparts.lifetips.com/cat/61...rol/index.html