I'm going to gut my cats. A friend of mine did it on his 2000 vette and felt a huge difference. Well a difference he can feel and thinks it added 20 to 30. Who's gutted their cats? What gains did you feel? How hard is it to do on an LS1?

 

i installed a bassani offroad Ypipe, which is 2.5" back to a 3 inch collector. now i think i'm being held back by the crappy Ipipe that the shop iinstalled, but i'm having a mandrel bent pipe installed this week (hopefully).

i noticed a small gain, but nothing mind shattering. honestly not sure it's worth it. i'm sure it's a gain, but realistically probably less than 10hp at the wheels.

although you do get a killer boost in exhaust sound

 

I have a bullet muffler/resonator and I wonder how much louder would it get the cats off? It should help my n2o setup.

 

slim to none, maybe 5 hp

 

OMG..
I am getting tired of butt-o-meter reports. Until someone forks over some $ for some dyno and track time I dont believe it.

Gutted cats have never made my cars feel any faster.. And I have had them on 3 different cars. Hi flow cats = good. Test pipe = better!

just dont believe the hype people.. High metallic tinny sounds come from gutted cats... not to mention sick tickets in pollution controlled states.

 

It doesn't look like its worth it. I will leave them alone until I get my headers and put on some high flow cats.

 

Just get high flow cats. Gutted cats sound awftle on LS1s and the gains are defenatly not worth it.

 

Unless your stock cats are plugged, don't waste your time or money messing with them. You'll gain less than 5hp, which cannot be felt with the butt-o-meter, your car will sound like a garbage truck. I know, I gutted the cat on my '94 (it was plugged), I had a new cat installed within days, it sounded so roachy gutted, it was embarrasing.

 

On my 2000 LS1 the Bassani off road y-pipe was good for 1 tenth and 1 mph consistantly.
But I didn't do this mod for the power. I'm running a 2 step rev-limiter for the launch and you can't do that with cats on the car.

And by the way, in reference to the comment about gutting cats, 5hp for free is well worth it.

 

would it be worthi it if it made your car sound like crap? What about the possible ticket? Would that be worth it? Here in Houston there are some cops that knowwhat to listen for and will site ya for gutted cats..

 

I gutted mine and hated the sound. At the track, I didn't see a difference.

So, I put my stockers back on.

 

I believe each car is different with sound.. If two LS1 Z28s from the factory puton the same exhaust, flowmaster, Borla, or loud mouth that would both sound a little different, mabey one better then the other.
A friend of mine had the exact same exhaust as me, i had a flowmaster on my car and he had Borla. Thye both sounded wimpy on my car and BAD *** on his car. And my car was even quicker then his but onky sounded half as good. Ive also heard LS1s with Long tubes, no cats, and the SLP loud mouth and alot of people thinks it sounds bad, i think it sounds BAD ***. Sometimes u may have to do some research and testing that may be expensive and require alot of time under the car to get a sound your happy with. I like the Loud mouth on my car more then i did the flowmaster and Borla combined. But im at the point right now, where i dont care how it sounds, as long as it hauls butt im happy.

 

I myself don't consider " gutting " a cat a mod at all. Nor would I ever say I did it.

It is a cheap way of ruining $500 worth the stuff. Get off road pipes or high flow cats.

 

Most, if not all, 2 steps work buy shutting off the spark to limit revs.
Shutting off the spark with the go pedal on the mat leads to a very rich mixture which will at best ruin the cats and in the worst case blow them right out from under the car .

 

Well I guess that would depend upon the usage and focus of your plans. For a street car in an area with picky cops, yeah not a good plan to excite them. For a car intended for the track or in an area where the cops would rather write a window tint ticket than a real moving violation well then different story.
And sounds like *** to you might be music to others. You can not press your point of view onto everyone else. We all have one of our own.