I have heard alot of different stories of there car not running right after punching out the cat, some other people i know with j bodies have done it with no problems to the car at all, so i guess what i am asking is there anyone out there who has had problems after doing it, my car is a 2001 if it helps.

hollowed cats cause flow stagnation. basically you lose power. if you dont mind loss of power, then go ahead. this is the reason most decent companies include a test pipe with their kits, so exhaust gases dont expand, cool down, and slow down in a hollow catalytic converter.

and since you have nothing more than basic boltons, running without a cat or a gutted one takes away more performance than anything else.


just because others have done something and had no problems, doesnt mean it helps.

thats why you see so many sport compacts with a 3 foot wing. most dont have any problems, but doubtful it helps performance. at most a 1 foot with side dams will help lateral stability in turns if you get the speed up on a road point. case in point.

dang Event beat me to it,

theres a guy I know who is running catless, is that a word.? he has a header, and intake, same engine as me. he steps on the gas and your wondering if the car is gonna reach 60. not about how fast he's going to get there.

Thanks for the imput guys.

no probs here, but it's all pipe that starts 2.5 at the collector, then tapers down to 2.0 a little before the rear axle.



CAR GODS MADE THE 1.6 SOHC TO MAKE US 2.2 OHV GUYS FEEL BETTER.

I am running catless. the noise is all that bothers me



96 All motor 5 Speed Z24, Best time 15.97@86MPH

I cut out my cat when i didn't feel like welding up my high flow. It got extremely loud and deeper. Ok to put around town but if you hit over 3grand your hearing that from about 3 blocks away. One question though. I didn't feel a loss in power at all. If anything my climb through 3rd gear improved a lot. Is it the fact that I never put the high flow on to compare it to that? Also, if i were to cut my cat apart, replace it with a straight pipe, then weld something up so it looks like i have a cat on there, wouldn't that be better then having a high flow on? I was always told, and read on here, that you want no back pressure for best performance. ( and really not trying to turn this into a back pressure war again and high jack this thread.) Just thought that a clear path through would be better then traveling through the honey comb. Anyone?
Thanks


Rich

mine sounds like pure ass, if I was to stick base ball cards in my spokes it would sound better. I am having a power issue as well but not sure if it's from the cat yet...


HP Tuners | Garrett T3/T04B | 2.5" Charge Pipes | 2.5" Downpipe | 650 Injectors | HO Manifold | Addco front/rear | Motor Mounts | HKS SSQV | Spec stage 3 | AEM UEGO Wideband | Team Green LSD | FMIC | 2.3 cams | 2.3 oil pump swap | 280WHP | Now ECOTECED

rich222 wrote:I cut out my cat when i didn't feel like welding up my high flow. It got extremely loud and deeper. Ok to put around town but if you hit over 3grand your hearing that from about 3 blocks away. One question though. I didn't feel a loss in power at all. If anything my climb through 3rd gear improved a lot. Is it the fact that I never put the high flow on to compare it to that? Also, if i were to cut my cat apart, replace it with a straight pipe, then weld something up so it looks like i have a cat on there, wouldn't that be better then having a high flow on? I was always told, and read on here, that you want no back pressure for best performance. ( and really not trying to turn this into a back pressure war again and high jack this thread.) Just thought that a clear path through would be better then traveling through the honey comb. Anyone?
Thanks

cats are beneficial for high exhaust velocity, especially since most here have basically stock engines.

Quote:

BACKPRESSURE = TORQUE?
An old hot-rodder's tall tale: Engines need some backpressure to work properly and make torque. That is not true. What engines need is low backpressure, but high exhaust stream velocity. A fast-moving but free-flowing gas column in the exhaust helps create a rarefaction or a negative pressure wave behind the exhaust valve as it opens. This vacuum helps scavenge the cylinder of exhaust gas faster and more thoroughly with less pumping losses. An exhaust pipe that is too big in diameter has low backpressure but lower velocity. The low velocity reduces the effectiveness of this scavenging effect, which has the greatest impact on low-end torque.

Low backpressure and high exhaust stream velocity can be achieved by running straight-through free-flowing mufflers and small pipe diameters. The only two exceptions to this are turbocharged engines and engines optimized for large amounts of nitrous oxide. Both of these devices vastly increase the exhaust gas volume and simply need larger pipes to get rid of it all.

i think i post this atleast once a week now


having a high flow cat period is the most efficient and effective choice.

simply because the catalyst acts as an oven to keep the gasses hot as it goes through the exhaust. when there isnt a second source of keeping the gasses hot, it cools down.

cars putting down alot of power....dont have to worry about this. for those who basically are stock engine wise...this affects you. its been dynoed accurately before, and its still the same game.

butt dynos arent really accurate.

if you take off your cat and have a oxygen sensor afte the cat the computer is going to throw a code. I say it would be safe to take off your cat if you have no 02 sensor after the cat. If your thinking about gutting ur cat your better of leaving it how it is. But if u paln on putting a straight pipe instead, with no 02 sensor after the cat, i say your safe but your vehicle might not pass the smog test.

IRONIC SAME TITLED POST IN THE NEWBIE FORUM






M.I.L.F. HUNTER Its quarter past 12:00 know where your mom is................................I do

Event, thanks for clarifying that. I never really understood that thats where the catylist part came into play. Looks like next mod is rebuying the high flow cat. Much appreciated.


Rich

i'm just a cheapass. the diaphram on the pressure regulator blew, went way rich and could roast marshmellows on the cat. then of course it clogged. so a piece of $3 pipe took it's place. and my CEL finally burnt out, now if the ABS could go too i'll be all set.



CAR GODS MADE THE 1.6 SOHC TO MAKE US 2.2 OHV GUYS FEEL BETTER.