hawk 7

iTrader: (2)

Has anyone ran the full turbo back 3" exhaust from racing beat with a 3" high flow cat in place of the pre silencer?? Do you think this set up would pass emissions?? Would there be any HP loss by putting a high flow cat in place of the pre silencer??

neofreak

It should pass smog, on my old FD passed the sniffer with downpipe and stock cat.

It won't pass visual, if they bother checking for a pre-cat.

breesej

It "should" pass smog. You might notice less power, but a cat on the S4 cars is good since the wastegate is so small, the cat would help control boost.

I'm planning on putting a 3" cat on my car when I install my RB setup. I just need to wait for the DP to come back from Jet Hot Coatings.

Scott 89t2

I have one. I passed smog. (you might not pass a visual...?) and it keeps my boost down to where I want it it would go higher without one.

I bought 2 flanges from racing beat cause I couldn't find anything in local shops that would match..

and I had a local shop weld in 3" SS pipe between the flanges and cat.

hawk 7

iTrader: (2)

Which 3" high flow cat are you using for your car??

Scott 89t2

Mine's a "magnaflow" universal 3" with air hook up. it was like $80usd or so.

hawk 7

iTrader: (2)

Is this one the same length as the pre silencer or do you have to have it modified to fit? Do you think it will stand up to the heat the rotary engine generates?

Rotorific

iTrader: (1)

An RX-7 wont pass unless it has atleast a main cat on it. With that is will barely pass. Another thing to have is an
airpump and ACV I think your setup will pass but barely. -Gabe

Scott 89t2

with the airpump and ACV hooked up. my readings with that cat (3 days old) and the 3" downpipe where almost exact to the stock cats (12 years old).

the cat is shorter. you just get some 3" pipe welded between the cat and flanges to make it fit.

mines been in for 6 months or so and still seems fine. I removed my airpump though right after the test which should make it last longer.