High Flow Cat.

[Moby45]

I am currently in the making of my car have a 3 inch cat back instead of a axle back exhaust. I custom make my own exhaust.

I already have the axle back portion done and its been on my car for about a year now.

Anybody have any high flow street legal catalytic converters that I should look for? I noticed ours on our car(year 2006 WRX) is kind of flat and only is a 2.5 diameter.

If you guys know of any to purchase then let me know. I need it to be 3 inch going in and 3 inch going out that isn't too big to fit under the car.

Thank you much.

[KevinWelker]

summit and jegs are your friends.

[02wrxRally]

^what he said, but I'm confused about what you have so far...

a cat back from what I know is an axle back plus a straight pipe - the stock one has a resonator that some mistake for a cat. Is that the portion you're building? Or are you building the rear section of the down pipe that has the last cat and the 02 sensor?

[Moby45]

My mistake. It is the resonator then.

I am building the part that comes after the Cat with the O2 sensor. Whats been on my car for the past year(what I call an axle back) is the part that starts from the last exhaust flange back. Basically, the muffler and the pipe that was attatched to the muffler.

I took my muffler off and straight piped it out.

So basically, the big long flat piece in the middle is just a resonator? If that is the case I should just be able to take that out all together and not have to worry about it not being street legal because its not a catalytic converter.(Correct me if I am wrong.) All I will have to do is see how loud its going to be and adjust from there.

Again, Thanks for your help.

[Rally OBXT]

That is correct. The big flat piece is just a resonator, not a cat.

[Gnome]

it will also lose some its good sound although

[RS MN]

it will also lose some its good sound although


i disagree.
ever heard a car with a stromung catback?
theres no resonator in the midpipe, its just straight on back to the back box, and its one of the best sounding exhausts i have ever heard.

[Gnome]

ill google it, i just figured resonators made my car once straight piped made pop and crackle a whole lot more than i wanted. this is once they were missing/taken off

[RS MN]

a resonator is just a muffler, so without a backbox and without a resonator, theres bound to be alot more noise than there would be with one in there,

but from what i am understanding from the OP, he already has a backbox.

personally i like loud subies, so i feel that 1 or no mufflers is enough for me, but some people prefer them quieter but still with a good tone, so they have 2 mufflers, the resonator and the backbox.

[Gnome]

i see, yours has a resonator am i correct?
becuase when i hade mine it was all the way straight thru and louder than all hell. josh's which i need to get a sound clip of is the same but with a magnaflow can on it and it sounds almost exactly like our other friends Bugeye minus the spooling turbo etcetc

[RS MN]

yes i only have a resonator. well that, and my stock cats.

[Gnome]

ah yes joshs is fully catless