those of you that have a 2.5inch downpipe to a 3inch exhaust system, what cat did you use?.. i have a maxrev 2.5 dp going to 3inch piping to a 3inch jic muffler. im looking for a carsound cat 2.5id-3.0od... can you guys let me know where to purchase this?..whats your setups?..any advice appreciated

 

i'll tell yah mine , got a 2.5 dp from drag going into a 3 in flex pipe connected by flanges to the 3 in carsound cat and downpipe, snaking all the way back into by custom 3 in piping, and out of my apex n1 turbo......help this helps

 

No cat You just gotta have a friend when inspection time comes

 

what cat?? i got obd1 i don't even use it when i get inspected lol louisiana inspections are easy

 

im thinking theres a carsound cat with a 2.5inch inlet and a 3inch outlet.....anyone?

 

I have the same dp as you and used a 3" in/out carsound cat. I had the end of the dp flared out to accept a 3" flange.

HTH

 

I run no cat but I also live in emission-less? florida!

 

You could go with a tapered adapter from your 2.5 tubing up to a 3" cat and then flange the outlet of the cat for your b pipe. For a FI set up I'd go with the 93009 Carsound since it is their heavy duty cat rated for up to 7.5L

 

to all you who dont run cats. WOW you gain 1whp.

At least get a hi flow cat. And you wonder why cali has such high emmisions?

I can see the point of running no cat at the track. But why on the street?


[Modified by machaf, 9:16 PM 12/30/2002]

 

to me then
no cat

 

I have 2.5dp into 3in flex and no cat. Why not run no cat. We dont have inspections here (kansas)so why not run one? i understand that it is harmful to the environment but if we were that worried we wouldnt be running turbo setups

 

I had my 2 1/2in. Revhard downpipe extended with the first o2 bung welded in, then a flex pipe, then extended with the second o2 bung. then the pipe flares out to 3in. with the flange to my 3in thermal catback.

 

i'm going to be using the 3" Carsound cat with 2.5" Maxrev DP and 3" exhaust/muffler. i'm using the 2.5" Carsound cat on my N/A setup currently and i like it. i got it from Testpipe.com for $112 shipped with flanges welded on. the 3" cat is what i have waiting for the turbo setup. i recommend you go with the 3" cat for the most flow.

 

**** CATS and high flow cats, trust me you make more thna 1whp without a cat
and what about all thme big v8's around with no cats. they are alright thoguh right?
screw that im running no cat and open wg , will prob run open dp too sometimes.
the enviroment aint gonna get any worse thatn it already is

 

Hey I got an idea... Why don't you call Carsound and see if they are willing to make a custom cat to fit your specific need. I have always used the Random Technologies ones and when I needed one to fit my Civic and have a 2.5" inlet and 3" outlet they were more then happy to make one. And it didn't cost anymore then a regular one would have. To them it's still making a cat. They just have to change 2 things on it. The end pieces are pieces of pipe they cut and weld onto the cat body anyway. That's how they are all constructed. No biggie... they just grab a different diameter pipe. It's less of a headache then you think guys and you get a professional clean look instead of a bunch of adapter plates or welded pipes to cause restrictions. Do it right... and you'll be very happy with the results.

 

JRSCIVIC thanks alot man, thats a damn good idea.. ithink im going to give the company a call soon.. thanks again man.. hopefully they can do it and charge me regular price..

 

hey one question for ya.. how much it cost you guys that customized your cat...how much extra they charge?.. i am not able to contact them right now but just curious to know... thanks again..

 

Running without a cat gains MUCH more than 1hp. I was running my exhaust straight off the turbo for a while and when I had it hooked up to a 2.5" DP, stock cat and 2.25" exhaust, I bet I lost 30whp (or so the butt-dyno says). I feel that all cars should come with a cat from the factory, but if you have the motivation/insight to take it out for performance's sakes, I say it should be fair game. I'd think most people are too lazy, disinterested to do it, so us performance guys are barely making a dent in the environment

Anyway, just get the DP flared out to accept a 3" cat. I'm going to do that in the near future and it should be sweet...either that or get one of those electric exhaust cut-outs and keep my cat/quiet exhaust for cruising and run right off the DP when I'm goin *****-out

 

yes you gain much more than 1HP when running no cat on a turbo setup, but i like to keep things clean (like the air even though it's already polluted) and by the books since i normally have emisions testing done for inspection.

Testpipe.com and others can fabricate just about anything you want as far as flanges, pipes and cats. just call and tell them the details, and they'll make it for you. welds on the outside with flanges that match diameter for smooth flow.