celm

I need to put a new cat on my FD, I am going to keep the air pump on.
what aftermarket hi-flo cats have you guys used or recommend? since I am going to keep the air pump on, I need to get one with the airport that comes out of the converter correct?

dcchris311

The rx7store has one with the air pump connection.

jutFD

iTrader: (2)

Bonez seems to be a great choice, heard good things. Never tried one myself

celm

the ones from rx7 store and bonez are $400+ ,has anyone tried the universal hi-flow magna flow cats?

bajaman

I've got a Pettit unit that I've not put on yet, it has the bung for the fitting...if I remember right. I haven't looked at it in years...

I remember pricing a new OEM cat one time, it was like $2400...lol!

celm

what u looking to do with that?

adam c

iTrader: (2)

What is wrong with your stock cat?

celm

I want to put a new hi-flow bigger diameter one

adam c

iTrader: (2)

Your stock cat has an effective diameter of 2 1/8 inches at both ends. The flange welds are on the inside of the pipe, obstructing the flow. It can be opened up to 2 1/2 inches fairly easily. Going from 2 1/8 to 2 1/2 is a big difference. Do the math. It works. I removed my cat, re-welded the flanges on the outside, and then ground off the inside welds until they were smooth. I was able to feel a noticeable difference in power after doing this.

If you choose to do this, I recommend that you "shake out" your cat when you have it out. You may have some loose bits in there that should be removed.

bajaman

I'm just hanging onto it. Someday I'll put it on, along with my PFS 'Purple' box....

celm

Sure u dont want to sell me the cat?

Supernaut

iTrader: (83)

Man I wish you were still living on the Island. I have a bonez cat I'm in the process of selling right now. Very low mileage to. I'm using an rx7store resonated mp now. I was shocked that I prefered the sound of the hi-flow cat over the resonated mp.

moehler

iTrader: (12)

I've gone back and forth with cats for 10 years. I'm over the rotary exhaust smell at this point. I changed my entire system to work better with a cat (smaller turbo, WI).

Bonez and Pettit are fine for a 300 whp or less car. Random tech makes a nice high flow bolt in metallic cat (which is what I'm going with). Vibrant makes nice quality, cheap, metallic cats. My last car used one and it worked great (welded into a 3" mid pipe).

elwood

iTrader: (1)

I'm considering adding a cat, too. I want to cut down on exhaust odor and lift throttle flames. I was looking at the Random Tech selection, and noticed that the universal race cats typically have a much coarser mesh -- 100ppi vs 300 or more for OEM.

Does a 100ppi cat make a noticeable difference?

Will a Random Tech cat last in a rotary application?

How far back from the turbo should it be mounted?

David Hayes

iTrader: (6)

Yes and they don't work. They are only rated up to 1,200 F so a rotary will cook one of them pretty quickly. I tried one on my 3 rotor and it lasted all of 200 miles. The sales guy told me they can handle up to 1,500 F but when the unit melted, the techies said they're good to only 1,200 F. Go figure.

Speed of light

iTrader: (8)

What adam c said....

The stock cat in stock form flows about the same as the typical 3" 300cpi HF cats, and can improve to over 500cfm @ 20.3" h2o if properly massaged (that's more than 590cfm @ 28" used by some). And not to mention they last.