Hop's-vette

Considering a change in exhaust system for my stock '81 to allow better breathing. Should I simply replace the catalytic converter and muffler's with high-flow performance type or have true duals run from the exhaust manifolds with 2 catalytic converters to the mufflers?
And for better air intake what should I do with the stock air-cleaner?

Avette4me

depends on your state laws...if ya can, deposit the cat in yer local dump...

and welcome...

Fang S-289

Double DITTO! I did and no regrets at all

CrossedFlags77

True duals will free up more power also if you add headers you will see a gain. Read Ganey's post about exhaust. There is some really good info.
http://www.corvettefaq.com/c3/ganeyexhaust.htm

Pauld

I changed to true duals on my '81 and the difference is truly noticable and it sounds far better too. If your state laws allow it then I would definatly go for it

Hop's-vette

Thanks for the feedback. Being in NY I probably can't get away with scrapping the CC but I will definetly have to use a high-flow unit....or 2 if I go true-duals!
Just for the fun of it, to see what the differences are, I may step into it by replacing the CC and mufflers with high-flow units and see if it's noticable. Then if I want to do more I can take it a local shop and have some duals fabricated for it, then I will only have to pick-up a 2nd CC.

Hop's-vette

And what about air intake? Anything I should do there or does the stock air-cleaner provide adequate breathing?

migraine99

Don't forget about your transmission crossmember! The member on an '81 only has a "dimple" on the passenger side to allow for pipe clearance. You may want to change it to an earlier model for clearance issues. I changed my '80's to one from a '79 which has the two holes on either side for the pipes. Then I had my exhaust guy install the true duals without the cat. BIG difference! Next step, headers and an h-pipe.

I hope this helps...

Chris

CrossedFlags77

On the subject of CC's you could always just hollow out the one you have now and stick it back on. You will pass the visual inspection if thats all they check for during inspection. And if you ever get pulled over you will be alright there also.

I am thinking of fabbing an intake that goes from the air cleaner to over the top of the radiator and sucks air from infront of the radiator. I am planning on using fiberglass. Noone really makes an aftermarket intake system. GrandSportC3 has a sweet cowl induction system on his Vette. You would have to get a high rise hood for your car and do some mods. Here is the link.

http://forums.corvetteforum.com/zerothread?id=640217

80TexasC3

Removed all of the original exhaust on my 80 and replaced with headers, true duals and Delta 40s. I love it!

BSeery

I would stay with the stock setup. If you have all the factory parts, that setup is a very nice one. You have a dual snorkel air cleaner base with a cold air intake above the radiator. It would be very hard to design a much better air intake system then what is already on the car now.