I am soon going to do the exhaust on my '89 Camaro IROC-Z. I am planning on a full 3" exhaust to a Spintech muffler to 2.5" duals. Can anyone tell me if I should just run it without a cat? I do live in CA so I will have to get it smogged in two years. Is there a way to put a removable section of tubing in place of the cat so that when smog comes around, I can just throw in a temporary cat? And will an exhaust shop do this for me? Thanks. -89IRO

 

at the spot where you put a cat in there you can have two flanges welded in on either side


then have a section of pipe with two flanges to bolt in there for most of your driving

and then use your cat hook two flanges up to that

this way if you ever need to put your cat in then all you have to do is undo a few bolts then hook that thing up....

 

Run the cat, that way you'll have some backpressure.
Sorry, couldn't help myself.

Seriously though, just get one , if a new Vette can run 12s with em, you can.

 

if your having it done by a shop in CA then youll need a cat. No shop would ever put the system together without a cat. The fines for making the emmmisions inoperative are pretty steep.

 

Shields- well, I don't think I'll be doing 12s with it but O.K. Since I live in Ca, should I go with that 16.5" Catco from Summit? ('89 Camaro IROC-Z) -89IRO

 

i have 2 cats, and when its time for exhaust i am going to buying two new cats.

 

My dad can get you a great deal on a better CarSound cat and do the install for you. Get ahold of him in the SoCal forum.

I run 12's with dual CarSound cats.

 

oh you can still get it done


just have to know the right ppl

 

rx7speed- hey do you live in CA (So Cal)? If so, do you know where I could get that done? Well, I guess if you don't, I can ask my race car driver neighbor- he should have some connections. How much HP do you think the difference would be between a new cat and no cat? If it does come down to me having to put a new cat on, should I go with a Catco, Dynomax, or Magnaflow? -89IRO

 

My guess would be 2-5hp prolly. I'd go with Catco, most people seem to like em.

 

I don't live in socal anymore

used to live in reseda at one point though



but if you know anyone with a welder you can have it done by them instead


biggest reasons I would go without a cat is
less backpressure trust me it's better
cheaper
less prone to failure
and just sounds a lot better

 

O.K., so tell me if this is correct for what I need to put in place of a cat- a 3" wide x about 21" long piece of tubing, and two flanges to bolt up to the two sides of it. Do you think 21" is too long though? Maybe I could go with an 18" long piece instead. Oh, and will I need two gaskets for the flanges? O.K.- tell me what you think, I will ask my neighbor if he can weld it for me. But the only problem is, when I take it to the exhaust shop, they probably won't do the work for me (tubing and muffler) because I don't want a cat. -89IRO

 

If you get a catback it should be pretty much a direct bolt on and will probably be better quality than what a local exhaust shop would use. If you are willing to do the work yourself, I would go that route. I think a hooker cat-back is about 250 and should bolt right up.

Ben

 

I've found (at least the two times I did it) that muffler shops will still build you an exhaust with no cats if you bring the car in on a trailer & tell them it's a drag car only. Don't forget to take the plates off.

 

I was thinking of gutting my cat too. Friend of mine who owns a 87 Grand National told me to do it, says probably at least 10HP gain, not to mention louder.

Should i guys? I mean lets put it this way, i'll save like $200 from getting a "high flow" cat, and it probably wont be that much better than stock right? And if my cat is bolt-on that would great, i gotta check it out, that way i can pop it in and out if i want.

Thanks.

 

I would suggest sperical flanges. more gaskets more leaks

and as far as hollowed cats are concerned, if at all possible stick a pipe in there. the shape of the cat housing with no catalyst in there is bad for flow. It also doesnt sound good untill the real high rpm. I ran a hollow cat for a while and it sounded more like a dumptruck than a racecar.

 

I heard someone with an older firebird that wanted to still pass emissions but have the least amount of backpressure/most performance. Here in MO they have Emissions Vans on just about every freeway randomly placed year round... so the flange and bolt on idea won't work here.

Anyway, he claimed to have opened up the cat, eliminated all the barriers on the inside except the first one, and welded it back. That way it was basically a 'ghost cat' with minimal bp.

Is this even possible?

J

 

Dont gut your cat its just stupid. You'll gain MAYBE 3hp in the top-end and make your exhaust slightly louder. Then when inspection comes along you're gonna need to go out and buy a new one.

 

Yeah, i know... but he said he gutted it but it would still pass. Is there a certain point you can reach that would pass inspection, I thought you need the whole thing to pass.

 

dont gut the cat look at this first it might help :

Order and Tech 1-713-910-2226 rpm outlet


Max-Flow High Flow catalytic converters are designed to 25% more than stock converters

Description
Price
MAX96001 2 1/4" High Flow Universal Catalytic Converter $89.95
MAX96002 2 1/2" High Flow Universal Catalytic Converter $94.95
MAX96003 3" High Flow Universal Catalytic Converter $99.95

cant go wrong price wise..and performance wise and you'll be legal

 

Man dont bother gutting or taking the cat off. I wouldnt do it here in Ont Canada and our emmisions enforcement isnt nearly as bad as yours. Its not worth having to worry about getting pulled over and checked or putting one back in when emmisions come around. The way i see it, by the time you buy 1 new cat, 2 pairs of flanges and get the custom job all set up you could have converted to dual 2.125 or 2.5 inch cats... Besides cats are the one piece of emmissions equipment on our cars that actually make a decent difference in the environment so keep em if you can. If you gut it your going to have to buy a new one come emmisions time. If it was me I would just buy a high flow 3 inch and spend the money elsewhere.