kbacklund

Hey gang,

So, I decided to go with true duals on my 1978 L48 PC. I removed the old exhaust today and am going to order this system from Corvette Central (Magnaflow 2 1/2"). A few questions...

On the new exhaust, I am planning to use Permatex Muffler Sealer on the joints. I am also planning to wrap the exhaust with heat wrap to keep cabin temperature down as much as possible. Should I be doing anything else? For the clamps, will the standard U-bolt clamps do? Or should I go for the banded clamps?

Also, while the old exhaust is gone, is there anything that I should replace/upgrade? The car has ~23K original miles. It looks like plugs are a little easier to replace with the exhaust out and I know they are original.

Thanks!
Kurt

Crimson Thunder

If the plug wires are also original,I would do those at the same time. They will be much easier to replace with the exhaust off.

carriljc

I had some old headers wrapped before. I would not do that again. When I went to remove them (for some project) and I unwrapped them, it was immediately obvious that they had been terribly corroded--- they were paper thin and flaking apart under that wrap. You'd be better off having thing coated instead of wrapping.

theandies

If you're going to true duels you'll need a new transmission exhaust bracket.
64-74 Front Exhaust hanger





I went with a standard 2 1/2 inch system years in 2001 that is aluminum coated and they look like new to this day. Look for something like that or you could always go SS. Can't say they retain the heat but if you want to header wrap them it probably would be better to have coated steel than un-coated to keep them from doing what carriljc said. I do have a little header wrap under my composite spring and it's not rusting under there the last time I looked which was about two years ago.

BKarol

It appears from the link it is for a dual exhaust with an automatic and no headers?. The bracket Theadies mentioned I used for my dual exhaust but I have a 4spd. You need to check on what exhaust hangers are used for an automatic system. Found this but hopefully someone who has done the change can chime in: https://www.mamotorworks.com/Corvett...acket-618957-1

kbacklund

Yes, this is an auto with no headers. The Corvette Central system comes with a central hangar. Would this suffice instead of the transmission bracket?

kbacklund

Hmmm. An alternative is a . Wonder if this would be better...

tviscomi

I've used the DEI version on other applications and it held up very well.

theandies

Looks as if it would work OK. Is that a rubber isolator where it bolts to the cross-member. The only reservation I'd have is it's bolted to the cross-member. The trans bracket is above the rubber transmission mount so the exhaust will move with the drive-train. I think the pipes and more importantly your exhaust manifold wouldn't like being ridged with the engine and trans rotating a little because of torque.

HeadsU.P.

The trouble with any type of exhaust wrap is, it retains moisture. Most header companies will void warranty if wrap is used.
By all means use butt- joint band clamps. You will like their simplicity when part of the exhaust system has to be removed. Tough to do with the old "squeeze clamps".

kbacklund

carriljc

kbacklund-
Where did you find these hangers/clamps? I'd like to try that on mine.

kbacklund

0DEITIM

Hi Kurt,

I'd like to chime in and offer some advice and tips. Check out our Titanium exhaust wrap or our pipe shields. http://designengineering.com/titanium-exhaust-wrap/ . The Titanium wrap will help keep more heat in the pipes versus a pipe shield but both work for their purposes. We offer stainless steel locking ties which are basically stainless steel zip ties to hold the wrap on. http://designengineering.com/stainle...-locking-ties/ . You can also use band clamps or stainless steel safety wire to help hold the wrap on. As far as corrosion goes. Wrap doesn't cause corrosion, water, metal, and oxygen cause corrosion. That being said be sure your pipes are coated with a header paint, our HT silicone spray, or make sure the pipes are made of stainless steel. Steel pipes will rust or corrode no matter what if they are not painted or coated, wrapped or not. Also, header wrap will absorb some moisture but it typically burns off as soon as the water touches it, no different than un-coated pipe. The only way water would stay in the wrap is if you start the car, wash it or drive thru a swamp and then park it immediately. For some reason people tend to think wrap holds moisture even though it is wrapped around a surface that is causing enough heat issues to warrant wrapping the pipes to begin with. I hope this helps. Please feel free to contact me if you need any help or with any questions.

Thanks, Tim

kbacklund

theandies

I can vouch for DEI's titanium wrap. My sons Cobalt had a 1/4 crack in the exhaust manifold flex pipe and was leaking and sounded like crap. At the time I didn't have the time to replace it so I got some DEI titanium header wrap and their SS zip-ties and wrapped the flex pipe. I know it's a Bubba solution but it was only temporary. It lasted until I changed the pipe and that was about 4 months and it came off almost like brand new. That was with direct exhaust contact.
As a matter of fact I'm going to re-wrap my exhaust pipes that run under my composite spring with DEI titanium wrap the next time.

Backstop

Anyone tried that new Zyban coating on headers yet? They are claiming it goes on like paint but blocks heat better than ceramic coating or wrap.