hugie82

I'm installing the CC's True Dual exhaust and I purchased a CATCO dual in and dual out cat. I guess the tree hugger was coming out in me Anyway to install it I have to cut out the H pipe section and I guess use the cat as my H pipe. My question is, is it worth installing the cat and has anyone experienced a nice bump in power installing true duals on a mostly stock 82 vette?
Thanks

jb78L-82

Can't comment on True duals on an 82 but I did get a very big bump in power on my mostly stock 78 L-82 4 speed (Everything internally to the engine is stock but have zero pollution control, Holley 4175 spreadbore, K&N airfilter in the stock housing, Roller rockers) with McJacks shorty headers, 2.5 true duals, and Monza turbo mufflers-no cat no H pipe. I have heard that a free flowing cat will not hurt performance and do have a 1994 Mustang GT with BBK shorty headers, Magnaflow X pipe with 4 cats (2 pre cats and 2 free flowing magnaflow full cats, and a magnaflow cat back exhaust system and the car is much faster than with the stock system. I added the catted magnaflow X pipe after I already had the magnaflow cat back system and BBK shorty headers and the car got noticeably louder with the magnaflow X pipe and cats than with the stock H pipe. You should be fine assuming that your cat is free flowing.

terry82

the cats are up to you .true duals on a street car with a low hp motor theres some to gain but maybe not as much as your hoping for.http://www.mamotorworks.com/corvette-4-36-9217.html

bobs77vet

well.....if you have a stock manifold maybe not....it may sound better though.....if you add headers to the situation then absolutely....look at as the first step to making an engine breathe better and the rest that you will do will make it come to life

hugie82

Thanks everyone!!! I hear ya Bob, the 82 Crossfire came with Stainless Steel headers from the factory but I'm sure aftermarket would flow much better.
JB78, you told me what I wanted to hear. I think I'm gonna leave the cat off for now. I no longer have to go through inspection in NJ so smog police isn't a problem. My problem is running the spark plug wires under the dam motor!!!! Since I have the exhaust out and my starter is shot I figured wires would be a good idea WTF was I thinking!!!
Do I have too unbolt the engine mount and lift the motor????

terry82

now is the time to replace your wires .just cut the old ones

hugie82

Just cut the old ones and then what???
tape them to the new ones and pull it through?

terry82

you dont have to put them in like the factory did .run them on the top.

bobs77vet

i bet your stainless steel headers are pretty good.....

terry82

the factory headers are small.heres what you wanthttp://www.mcjackscorvettes.com/headerspage.htm

jb78L-82

I have McJacks and love them. Fit just like the OEM manifolds but with 1 5/8 inch primaries and none of the clearance issues of long tube headers and they hook right up to duals in the stock location-but pricey! I bought mine a few years ago for $495. I added the McJacks to my already existing 2.5 inch true duals/Monza turbo mufflers and the sound definitely got louder with that change alone-more flow!

LancePearson

My 76 small block stock with cast ram's horns was 2-1-2 through the horrible pellet cat converter. The whole system was weak, worn, loose, cracked manifold on one side. We jerked it all out, replaced the manifold with same kind since I wasn't going inside motor. True duals each with a bullet high flow cat converter into flowmasters. System sounds entirely different...no leaks, rusted areas, cracked exhaust man. sounds. However, I believe I gained 750 more rpm in the motor at top, know I gained 5-10 mph at the top of each of the three first gears (haven't tested fourth yet). The application of the power in each gear is now completely uniform, feels that way to me and it didn't before. The sound outside of the famous flowmaster drone at about 35 mph is terrific and I'm a happy camper. How much was tossing the crappy pellet cat converter monster and how much was the exhaust? i can't tell you but I sure like the results.

LancePearson

P.s. I try never to go 35mph except passing through and waving at it......end of drone issue.

terry82

the factory cats on a 82 are verry bad .but the new ones flow verry well .

LancePearson

many new choices but I used about 10" long bullets with ceramic grids coated in irridium I think. They fit on either end, are bigger in the center where the grids are and are probably next to no resistance. if the grids ever break I'm pretty sure they'll go right on through the flowmasters and out the back and I won't be any wiser or care for that matter. Every time I pull up behind a diesel firetruck or truck I forget all about pollution and the epa.

hugie82

The 82 cat is definately different than the earlier ones. Long and oval with a large oval almost 4 inch pipe but it was gettin rust holes after 100k and 28 years....
I would like new SS headers but I would like to keep the air pump and lines in place. I'm still debating on what to do with the air pump line that went all the way down under the car to the cat? I have a feelin if I leave it hang I'm gonna get some kind of noise out of it!

terry82

i left mine in place ,but i did tie wrap it down.save all your old parts.