off road pipes rule! not raspy either....cheese is right...!

 

I gutted mine when I hit about 80K miles...that little bastage was plugged up to the point that I'm surprised exhaust would even flow through it. Good and bad:

Good: more power at higher RPM, nothing to plug up again

Bad: less torque down low (reduced back pressure), tinny/rattling sound on acceleration, can't pass emissions without it

Think about it...when you take all the crap out of the converter, you're left with a hollow "box". Exhaust can't flow through it easily...it enters the chamber and bounces around like a mother before it finds its way out. Solution: chop the whole cat out and replace it with a piece of straight pipe. Problem solved.

As far as pollution goes...I see tractor trailers and heavy trucks dumping pure black smoke everywhere, all the time. When they stop polluting so damn much, THEN I'll worry about the tiny bit of emissions that my car is putting out.

 

I give a **** about polluting. That's who.

Rich Krause

 

I recently got an extra stock dual cat y-pipe from one of the guys on the board.... so I gutted the drivers side cat , and replaced the passenger side cat with 2 1/2" pipe , and with the 1 3/4" SLP shorties / B&B tri-flow it sounds very healthy..... a definite sound improvement , but with the cut-out open it kinda sounds like crap......but that was just sitting in my drive , I'll have to wait until spring to test under aload.

 

Does anyone have a sound clip of a nearly stock LT1 with gutted cats? I was thinking of getting the ORP with my mac headers, but wanted to see how they sound first.

 

I have basically stock car and i have no cats (ORP) and a cut out!...I run the cut out open 24/7! Its kinda raspy but it sounds BADDazz! I Love it. I definitly feel i gained h/p from !cats!...i recomend! good luck

 

When I had heads/cam and JBA dual cat shorty headers, I welded in pipe in place of both cats.

Gained absolutely nothing at the track.

On a dual-cat car, the size of the manifold/header outlet, and the y-pipe diameter is the restriction. Not the cats themselves.

 

Nothing personal rskrause, but your the only person I have ever heard of who does.

 

Woodsy The Owl says, "Give a HOOT, don't POLLUTE!"

Gutted cat owners say .... (add your own joke, this is just too funny)

 

Since no minds will be changed here, a long post would be wasted. So I guess we can "agree to disagree" about pollution.

I will grant that a clean running car without cats doesn't add a hell of a lot to pollution. But if you think air pollution isn't a problem, you're way off base. Many fine people I know with modified cars feel as most of you do, that it's nothing to be concerned about. I can accept that as a legitimate differnce of opinion. What I find annoying is that some of you find it necessary to get personal about it.

Anyway, as far as gutting the cats go, on most setups it will not make power. I spend a lot of time on the dyno with various vehicles and I have seen many times either no gain or even a small power loss when running !cats. Just this last Saturday we had a supercharged Dodge Durango on the dyno. I made the a couple of less rwhp and nearly 10lbs less torque without the cats. And yes, it sounded like s**t and smelled bad.

On high output vehicles with a good set headers and a non-restrictive exhaust downstream of the cats there will be power gains on the order of 10-15rwhp from replacing the cats with a high flow Y-pipe. If that's worth it to you, go for it.

Rich Krause

 

Where do you get a off road pipe and can I use it on my 97 z with a cat back system and no headers? Cheese 48 do they have any f body clubs up north IL? I live in Cheese land and these fakes don't seem to have any clubs?
Shawn Yes I am a Bear fan and the Pack sucks!!!!!!

 

A gutted cat adds turbulence to the flow of exhaust. If you need the extra throughput do it right and install a straight pipe.

 

well, I too give a **** about poluting, however...

When the government stops allowing large companies to crush old collectors cars so they can polute even more, I will be more willing to worry about it. Also, when catalytic converters stop costing so much damn money, I will also worry more about it. As it is, I can't afford to put a converter on my exhaust (when I get it done) and therefore I won't have one. At the same time, I realize whatever my opinions on it are, I would still be helping destroy the environment, so for me its sort of hard to decide

I have heard that removing the cats doesn't necessarily rob you of low end power, it moves it higher on the RPM scale. So while you may lose some low RPM torque your probably gaining it on the top end. For those of you worried about that, I don't know about you but I can already blow the tires off at any speed in 1st gear, so why do I want more low end that I can't use? Since I don't plan on a 12 bolt soon, for me losing low end and gaining top end is a plus since I will probably never hook up even what I have. Just something to think about

 

Uhh.....I don't know if emissions standards vary from state to state, but when Florida was doing regular tests (they were abolished a couple of years ago finally) a good running LT1 running STRAIGHT exhaust would never have any problem passing.

Cats are most effective at minimizing pollution at cold start-up....once warmed up, modern day fuel-injected engines are actually pretty clean.

Hell, I don't run a cat or a muffler......sounds fine to me.......say what?