if i cut my catylitic converter off and put a pipe in its place...will i be expecting to lose alot of power...im trying to make my Z louder and that seems like a good inexpensive way to do it...it should make a big difference in how loud it is right?? should i just keep the cat off or should i cut it off...if i lose too many HP then i'll probably just keep it on

 

Most people dont like the air pollution aspect, but i hacked mine off gained maybe 5hp. Did not make it much louder but changed the sound a bit. Local auto parts store should have the pipe you need in stock. You will need to clamp or weld pipe. Dont do this if you ever have inspection/ems! What year is the car ?

 

the only way you will lose hp is if you dont reprogram the pc to work without the cat. and that is just timing. the pc uses the cat to sense the oxygen in the exhaust and makes sure there is 13.4:1 ratio. with this ratio, the car will run at its best, making the most hp while retaining low emissions. without the cat, the o2 sensor will not work correctly and the timing will be automaticly adjusted to compensate, and you will lose mileage.

as for sound, it wont change much. if you have a catback it will be more noticeable, and with headers, you will definately be able to tell that the cats are gone.

id keep the cat for legal and inspection purposes, unless you know people

 

depends on your other mods. you wont loose hp but may move your tq and hp peaks up to a point that you wont be able to make good use of them. i had a 3" in/out flowmaster and put on y and o/r and it pulled great above 5000rpm but down low it had nothing. i changed mufflers and it woke up bigtime, but I had to get a muffler that did not flow as well. regardless of what people say, you need a certain degree of backpressure to produce torwue in a street engine. if you have more air going out than you have coming in it is called overscavenging and this causes you to not have enough air in the cylinder to properly ignite the mix which causes a loss in power.

 

I have Hooker LTs, 3 inch y-pipe with out cats, and GMMG exhuast for my stock engine. With that unrestricted exhaust my torque was over 300 RWTQ during my whole dyno run. You will not lose torque by cutting off the cats. If you don't have emissions and you like how it sounds go for it. Your power and torque will benefit.

Bryan

 

!Cat, sounds meaner, louder, and breathes better up top!! I don't have tuning yet but could tell a difference.

 

didnt say he would necessarily lose tq completely, but if it normally peaks at say 3500rpm and it moves up to 4500 rpm and peak hp moves from 5500 to 6300 you have just moved your peak numbers up so high that they dont do you anygood in a stock motor with boltons.

 

My peak torque was around 3500+/- and peak horsepower was 5200+/-. Like I said this is on stock motor with boltons and a very high flowing exhaust. Proof that a high flowing exhaust doesn't lose torque or move your peak power numbers. If you don't have emissions there is no reason not to cut the cats off if you want to.

Bryan

 

ya its a 94 Z...i live in texas and i dont think i have any emissions that i wiill need to pass...but my car wont getmuch louder ya'll are saying?

 

the car is all stock and how could i reprogram the pc

 

You dont need to reprograme since you have a 94 . Its worth it. You dont need that much backpressure, its like runing with a mask on.

 

Screw getting a pipe to go in its place. Get a pipe and a big hammer and beat the snot outa the stuff inside like a red headed stepchild. Start the car and blow all that junk out...watch out, that "stuff" from inside can give u a nasty rash

 

ya i used to have the cat gutted...but it didnt change the sound too much and also it seemed like my car was sluggish...so i got my neighbors stock cat and put it on mine...but thinking of cutting it off

 

I am also considering getting a test pipe. Can anyone here speak of experiences with them? Thanks. Noah

 

your gas smell will be different. not too intolerable. kinda like a lawn mower or weed eater smell. my buddy exchanged his cats for staight pipes, he didnt lose power, but it was louder. not significantly louder, but noticeable. if i did anything, id get a high flow cat to replace the stocker unit. they seem to fare well with the race oriented and those wanting to remain legal. just remember, too little backpressure and the car will run like crap. backpressure helps the valves seal.