I have the turboxs midpipe and exhaust, and recently I wanted to get it to be quieter. I thought one of the best ways yould be to weld in a universal cat, but I called up a muffler shop who told me that its illegal, blah, blah, blah.
I'm already running a catless midpipe so the legality is what concerns me least. I just want it quieter and removing some of that ear burning scent would be a nice plus.

Also the stock cat has a O2 bung in the middle, so would I have to buy a universal cat with a bung in the middle? or can I put it behind the cat?

I thought of selling the midpipe and just buying a highflow cat, but I heard the midpipe only works with the turboxs exhaust, so the buyers would be limited. Does the exhaust work with high flow cats?

 

I would just weld in a resonator, for a deeper quieter sound with low restriction.

A uni-cat will last only a week or so at the outlet temp of an RX-8.....

S

 

I have the TurboXS exhaust and yes it is loud

get some fatmat and do your interior and double up in the trunk

that way you wont hear it as much on the inside but the people outside can still hear it

 

I have installed an all metal HiFlow CAT into the TurboXS race pipe. Helps with the sound and the smell. I have no problems so far, after about 500 miles.
http://i510.photobucket.com/albums/s...8/IMG_1148.jpg

 

Forgot to say it is a 'Magnaflow' Part No.59959. This is an all stainless steel CAT.

http://i510.photobucket.com/albums/s...8/IMG_1150.jpg

http://www.car-sound.com/02product/d...niversal=59959

 

looks good, ill look into getting someone to weld one on for me. So the bung for the second o2 just goes after the cat, right?

 

Yes that 's correct. I did this so as to keep the 3" piping with a quick way of removing the CAT whenever. Cost to me is not an issue as the engineering needed is in-house, but might be an issue if I had to pay the actual total costs involved.
The alternative is to buy a high flow CAT midpipe which should have the same or similar results.
NB: I should also point out that the high flow cat will only reduce the noise slightly. What it has done in my case is deepen the tone and as such is more acceptable.