Write-Up: Wrapping Exhaust Headers

Abbadon's Write-Up: https://rivperformance.editboard.com/t9388p15-write-up-wrapping-exhaust-headers#108384

AA's Write-Up: https://rivperformance.editboard.com/t9388p30-write-up-wrapping-exhaust-headers#146872

If you decide to wrap the flex pipe, as I do, usually it needs redone about once every year or two because the wrap tends to lose tension, fray or become unraveled after a while, especially during the winter months.

This was my 3rd time wrapping since I installed the headers in Mar '06. The pipes and flex braids are still in good shape underneath. This time, I wrapped the material the same way, but gave the last layer a generous coating of high-temp RTV. Hopefully, it will help keep everything dry and in one piece:

hmmm, interesting idea. I'll have to look into that. Wonder how easy it will be to re-do if needed.

Is that the stock sway bar or addco?

Addco. I think it would be very easy to redo, if I ever need to. Just cut through the RTV layer and then it's dry wrap. No RTV touches the actual pipe or flex braided area. Hope this is a permanent fix, as I'm tired of redoing it every year. Wrapping it dry, the inside of the wrap has been fine, just the outside comes apart and causes the rest to become loose and undone.

I think this also helps to waterproof the wrap, so might keep it from rotting over longer periods.

you should travel to Egypt and do extensive research on mummification. then, using that knowledge, find a way to permanently wrap the flex so that no spirits...i mean... gases penetrate it.

Uh... yeah!

AA wrote:

Uh... yeah!

FIRST TIME EVER TO USE THE MUMMY THINGER WOOOT WOOOT

The trick to doing a good header wrap is to soak the roll of wrap in a bucket of water before doing anything with it.
I have done several automotive headers and motorcycle headers this way for too many years to admit.
You can use a 2" wrap saturated, wring it out and start at the flange area with a double wrap and just a normal worm clamp to hold the first wrap in place and pull the remaining wrap as you are squeezing water out of it and continue down the pipe, as they intersect just wrap the 2 or 3 or 4 together as one and at the end double wrap again and cut with a pair of scissors and clamp with the stainless clamps that come with the header wrap.
When your doing the rear header on a 3800 start out the same and just overlap the header wrap even tighter on the flex joint and keep pulling the wrap tight as you go. then clamp it off.
Now you have to wait till it dries. depending on temp , climate and amount of hot sun you might get depends on how long before you can remove the temporary worm clamps and put on the permanent stainless clamps and then paint with the silicone header spray.
I was able to get 3 nice even coats out of one can for the 3800 headers.
By putting the wrap on wet you get the flexibility you need to work with it and as it dries it shrinks tighter than a drum and will last many years.
Just my experience with using the products mentioned.

Yes, I seem to remember the instructions saying to soak the wrap in water. I think the main purpose of this is to keep the fibers from becoming airborne. The stuff I used didn't seem to be any more 'stretchy' when it was wet vs. dry.

I have found the 2" header wrap to be much more compliant and stretchable when working with a complete header. Even the ones on my car, which were the first set of 3800's I've ever done, but all have been the same.
Yes it does prevent the ends from fraying as much, but it also give the product some elasticity and if you have clamped it good, and let it dry, it is tighter than a drum. Which lends itself well to using the Header paint which has silicone in it (actually called Hi-Temp Silicone Coating) and provides for a much longer life of the header wrap for sure.

Header wrap is one of those things if done correctly can help extend the life of your headers, but if done incorrectly, will help them to rot out pretty quickly. Great info Rick.

If my car ever gets to rowdy, I plan on wrapping the entire exhaust back to the mufflers and including the mufflers. I know someone with a 750hp blown 383 sleeper grandma Malibu, he wrapped the entire exhaust and it quieted it down more than you would think. Least till you really get on it.

The new graphite color wrap looks pretty nice. I like it better than the hemp-looking stuff. Of course, it doesn't matter if you plan on painting them.

That is about the color of mine with the spray coating on them.
I guess we shouldn't call it paint as it is a silicone coating in an aerosol can. To be technically correct.

Another tip, wear gloves when handling the wrap. It's like a fiber glass, makes your hands itchy.

lol @ itchy hands. Thanks guys. I have enough little "paper-cut" slices everywhere (I've been doing alot of work in dashboards lately) and making them itch on top of it would make me shoot myself....Hopefully I can get them done tomorrow so I can have the paint guys bake 'em in the booth before I install.

Excellent you have heat lamps and a spray booth available, should be able to do a very nice job.
Don't forget NOT to wrap them where you are going to need the space to clamp them together, don't worry about trying to get every millimeter covered..
I know it sounds elementary but I have goofed up before and put the wrap to close to the joints and after it all dried and was painted I had to take a razor knife and cut some off, well that caused some fraying and ruined a perfect job.

Rickw wrote:

Don't forget NOT to wrap them where you are going to need the space to clamp them together, don't worry about trying to get every millimeter covered

I'm going to put the system together loosely on the ground while the wrap is soaking so I can make marks of where to start and stop the wrap, with a little bit of breathing room around the clamp areas....Thanks for the reminder, it sux being all excited to get sh*t done and do it wrong  

Any updates, how are you making out with this project.

Well, as close as the pipes are together, it's a complete PITA to wrap them. I got the crossover pipe and the flex joint done. I'm fighting with myself if I should try to wrap each individual pipe. The main factor is trying to wrap it all in one piece, and I'm starting to believe that on this style of header it's impossible. Unless I can wrap 6" of pipe at a time, I'm thinkin I'm gonna give up on it Any suggestions would help....

...and yes, gloves are good, but don't forget to wear long sleeves!
My forearms are driving me nuts!

Maybe try it with the 1" stuff; it will be more flexible and easier to navigate the primaries, imo.

I decided just to wrap the crossover. The primaries were too much work and really not worth it IMO.

eh, I was in a hurry. I was planning on installing tomorrow, but we got busy (which is a good thing), so I'll have to come in and finish the wrap instead. When the painter found out that the paint is Silicone based, he said he'd kill me if I sprayed it anywhere near the shop.....so I guess baking them after paint isn't an option....

I just brushed on the RTV from the tube, you can do it with your finger. Spraying it would be a messy operation.

AA wrote:

I just brushed on the RTV from the tube, you can do it with your finger. Spraying it would be a messy operation.

Not the RTV, the Silicone High Heat header spray from DEI....the only stuff that's safe for painting wrap.....

The high-temp RTV used for sealing the clamp joints is definately safe for painting header wrap. It's actually thicker than the spray, and has held up fine on mine for two years so far. See page 4 of this thread.

Ah...ic. We just tested the spray on some wet clearcoat, it didn't fish eye....so he's lettin me spray 'em in the shop now.

On a diff note....I'm takin apart a Viper right now. The downpipe-to-resonator connection is the exact same as the SSAC DP....even has the same clamp LOL