I was talking to a fellow Z28 owner (He's got a beautiful 1996 Z28) and I asked him if he's got any mods. He responded by telling me that the car is 100% stock except for the removed cats. He said he now just has his headers, without the cats, and the muffler in place but not working.

Then I asked him why he did that, and he told me that first of all the sound was incredible with out the cats. Very loud and a great sounding exhaust. And also he said that since the catalytic converter is restrictive he even gained quite a bit of performance with this mod. And he also told me it was illegal, but no one's ever told him anything since he still had his muffler in place and at a glance the car looks normal.

Is all this correct?

 

....sounds about right.... what did you doubt?

cats are very restrictive
no cats are very loud
no cats is also a FEDERAL offense (huge fines)
but who would know???

 

I don't know, it just seemed too good to be true... like a myth.
Besides the loudness and gain in performance, does it affect any other driving aspects? Could it be bad for the car?

 

well, for one, whoever drives behind you is going to have his eyes watering. The smell is terrible, acrid, and burns. Standing behind my car makes my eyes water and sting.

Yes, I have an offroad pipe (its just a hollow pipe that replaces for catalytic converter. I prefer to call it a super-hi-flow cat). However, I ordered a bolt-on MAC hi-flow cat that I can just swap in an out.

Driving in traffic with the smell, noise, and risk of being pulled over and fined HUGE amounts is just not worth the 5-10rwhp it may give. Besides, some people say the loss of backpressure in the LT1 really takes away from the low end torque. I've heard the LT1 likes backpressure in the low RPMs - can anyone confirm/dispute this? I'd also like to know for sure as well.

 

I have had my cats gutted for 2 years now. I never smelt any bad smells when at stop lights, but I am pretty sure the people behind me have. I wouldn't do this mod as much for the performance increase, because you won't feel the difference, the the exhaust note takes on a louder, not deeper, sound. I have headers and GMMG chambered exhaust, so my exhaust is already very deep, not its just perfect. Yes, the LT1's need backpressure, but as long as you have a catback, you are fine. Although removing the cats on a stock LT1 or LS1 does sound damn good, I have heard a few with the stock exhaust, and they sound pretty good. Just remember to get the O2 simulators.

Travis

 

depemds on the muffler you go with. i had a single 3inch flow that sounded great with the stock before muffler exhaust. when i put on the ypipe and offroad it sounded likw a turnip truck and low end was nothing like before. i put on a dynomax quietflow muffler and woah what a difference. i had a buddy who gutted his cat and left the stock muffler. it sounded great and ran very well. he put a 175 shot on it and it ran 11.80's at about 115 i think it was. if you eant to try the loud wide open thing then get you a cheap cutout and install it with a good exhaust and just see for yourself what happens.

 

Would you guys recommend buying a perormance cat-back instead of doing this? If so what are the best bang-for-buck performance exhausts? From what I've been reading, a set of long tube headers with a custom y-pipe and aftermarket exhaust seems to be a pretty popular choice.

So what would the best brand of headers/exhaust be?
And should I get a high flow cat also? Or just go with no cats with the y-pipe?

Thanks for the replies.

 

If you want a good "bang for your buck" exhaust system then I would go with either the Hooker or Edelbrock. You can get both of them for around $300. As far as headers go, LT's are definitly the best to get. Hooker makes a great LT and also FLP makes them too. FLP will cost you an arm and a leg, but have proven to be one of the best out there. You can get the Hooker LT's for around $600 and then get a custom y-pipe made for another $200.