Fred D. Zwiger

anyone installed a true dual exhaust on an 81? Who sells them and what changes needed to make it work?

Thanks,
Fred Z.

grantv

01 or 81? 81 = wrong forum.
Didn't those years have dual exhaust?

JR-01

Nope. They were fake duals.




There are a lot of vendors that sell true dual kits for later C3s.

sullyman56

For my 77 L48, I bought a dual exhaust system for a 74. It fit perfectly and was an easy install.

PonchoVette

I have another thread on this in the forum. You can find a system at Corvette Central. I'm trying to figure out for myself how it impacts the O2 sensor and the EGR system.

terry82

you need the 02 if you still have the factory fuel system.If you go to tru duals the sensor may not like the open exhaust because without the backpressure the sensor may not get hot enough to work .try it first .but if it does not work the fix is to use a heated 02 sensor.

74 LS4-454

I have a true dual exhaust on my 82 without the cat. The 02 sensor is hooked up to the RS pipe. I can't remember if it is a heated 02 or not.
I have not had any problems at all with this system. Does not effect the EGR to my knowledge, never has thrown a code pertaining to the above mentioned. The PO had this installed with Flowmasters, I don't know where purchased, or if he had a shop do the work. I have owned my 82 for 4 1/2 years and put over 70,000 miles as my then "dd".
As I said, no trouble with this system. Great response when accelerating..... Tom

Fred D. Zwiger

Thanks for the help. Does the crossmember need changing?

Fred Z.

M. Young

My new crossmember came designed with true duals in mind.

Rky Mtn C6

This winter I'm doing the same thing with my 78. In Colorado cars from 1981 and newer are subject to emissions testing. Therefore, the cat is coming off, and the true dual 74 system is going on.

EASYGEAR

I looked for a early C3 crossmember with the two holes in it for the exhaust, when converting to duals on my 81.
That was recommended to me from the shop building the exhaust.
I found one of these old crossmembers and brought it to the exhaust builder.
When he started with it, he found out the left-side pipe ran into the driver side seat pan.
(We have used full length Hooker Super Competition headers)

This is only the case with electric powered seat. That seat was not available up to `80, optional in `81, 1982 was stock.

So without e-powered seat the old crossmember would be the best option i think.

They finally used the stock 81 crossmember and modified it, that way it worked, but i think the pipes still were a bit lower than it would have been with the older crossmember.

Also they had to flat out the left pipe where it ran below the driver seat floor, not a good thing but necessary.
Still needed some work later as at certain rpm it touched the seat pan.