how much power without cat?
 

i am contemplating removing my Catylitic converter from my 96 hatch,(i am using a ex style),replacing it with a 3"resonator and using that 02 sim from ecg..i have a custom 3" exhaust from the cat back..the cat i am using is a stock size catco..i had to install a bung fitting in it for the secondary 02..even that 02 takes up alot of internal exhaust space..how much to do you think that stock cat size is corking up my turbo and what can be expected powerwise if i remove it?

Re:how much power without cat?
 

I know your looking for an answer from this but i have a question for you..

i've got the same car and am wondering what the O2 SIM is from ECG???? I've pretty much done the same stuff as you, ex style cat cat- back exhaust and almost finished my turbo.. Just wondering what you did for the second O2 sensor so it will work fine after being moved??

Thanks kyle

Re:how much power without cat?
 

Yo.. be carefull with exhaust bore. Alot of people have gone with 3" mandrel bent cat back systems with a free flow cat or no cat.. If the exhaust "is" strangleing your turbo it wont anymore with this type of setup.. Problem being you may see a very different picture with regard to fuel management.. More boost needs more fuel.. Doing exhaust alone can cause a lean situation and tost things up real good.. Try it on someone elses car first.. ;D

Seriously this may be just what your after. but be ready to tweak your boost enrichenment / timing retartdation, e.t.c. if you go free flow and suddelny notice detonation this is axactly what has happened.

Re:how much power without cat?
 

Just hope you dont get pulled over without a catalytic converter, or at least by a smart state patrolman.

The noise you will produce with out it will be more then reasonable cause to have your car impounded in most states.

If you're using a hi-flow cat you're going to gain probably 5-15 horsepower at the most.

Re:how much power without cat?
 

the 02 sim mimics the voltage signals that the cat monitor (second 02) produces..if you dont have a cat that second 02 pics up that the cat is no longer working and throws a CEL..with the sim you remove the cat..the sim mimics what a second 02 should read with the cat installed..for my second 02 i just installed a bung behind the cat, extended the wiring and it worked fine..i am going to be running a resonator inplace that at least reasembles a cat..here in my part of PA ive never had anyone check for a cat..i also dont have to worry about emissions.i have a 255lph fuel pump , regulator and smc..so im sure adjusting extra fuel if needed will be no prob.if you need a cat..mines coming off soon.

Re:how much power without cat?
 

Dude, I have gutted and removed every cat on all my cars, and it really doesnt make it that loud at all. Just a bit more raspy. And after you put a turbo on, it quiet's the car down about 40%

Jeff

Re:how much power without cat?
 

and also makes the car sound much better not like a v8 or a bumblebee just right

Re:how much power without cat?
 

it did quiet down alot with the turbo..but i would like it quieter..i am hoping that 3' dynomax resonator i have will help..i got my info on the o2 sim..im going to order it.

Re:how much power without cat?
 

hmm... didn't think it would be any quieter with boost and no cat... I just remember firing up a 396 with no exhaust on it at all, and although the displacement is about 1/3 on the honda, it would still be pretty damn noisy :P

Re:how much power without cat?
 

the turbo itself acts as somewhat of a muffler..