Thermo Header Wrap
Is this stuff effective.
I have always hated headers because they make the inside of my car noisy and hot.

 

Well since my home made exhaust the car is noisy and it's always been hot....
Guys at the muffler shop told me to never use header wrap as it will make your headers run hotter and they hold moisture as well when cold.
That combination makes for short header life.
Brezynski Racing ports stock ram horn manifolds.

 

Who is Brezynski Racing. I did a search and came up with nothing.

 

I've heard a few folks comment that the wrap make the headers rust from the inside out, I can't attest to this personally. If heat is a concern, use some heat barrier, I used Dynamat xtreme, and it makes a huge difference inside.

Kid

 

Dude, you drive a corvette, if you want a car that isn't noisy and hot, you should check out a Corolla or a Civic. Those are nice, quiet, cool cars. : P j/k

I've run header wrap for a number of years. The reason peoples' pipes rust out is they don't treat the wrap with silicon spray. If you treat the wrap, it helps repel moisture.

This is an argument that has been beaten to death over the years, but ultimately the performance benefits of wrapped header primaries (especially in extremely long tube primaries such as sidepipe setups) are:

1. Reduced cooling of the exhaust charge from where it exits the head to where it meets at the collector.
2. The increased temperature of the exhaust charge at the collector means improved exhaust charge velocity.
3. The improved exhaust charge velocity enhances exhaust scavenging from the cylinder.

Most sources claim 1-2% power increase. Never seen anyone do a before and after dyno comparison.

The downsides of header wrap are:

1. fiberglass itches
2. if you don't treat it liberally with silicone, it will rot
3. the burning smell during in initial breakin
4. feeling obligated to respond to posts like this to defend header wrap, since it has such a bad rap (! haha)
5. over-tightening of wrap clamps can distort header tubes, potentially causing cracks (ask me how I know)

the blonde weasel

 

I meant to also add, if your interior is hot, have you already gone through all the factory heat blankets and shields to ensure they're there?

I installed some racing insulation I found at Summit, it's porcelain and fiberglass based, with an aluminized sheet on the outside. It's adhesive on the other side, so you just trim, fit, peel, and stick. My interior temps went down noticably after insulating the lower portion of the firewall.

 

I've used it before - not sure how well it really works but can't stand the stuff. Looks horrible - would only use it if you absoutely have to. Look at the cost of buying some ceramic coated headers vs. this stuff and decide if it's really worth it to spend all that time wrapping them with this itchy nasty stuff - which can be difficult to get & remain tight around the tight curves. I've since gotten rid of it and bought better headers (keep in mind w/headers you have to periodically tighten the bolts or you'll be replacing gaskets often and hearing lots of ticking sounds). I saved the header wrap for certain areas of the exhaust system only where is close to things like PS box, A-arm bushings, PS lines, etc. - just as an added heat shield.

 

I misspelled it but Googling still brought this up:

http://castheads.com/corvette_systems.php#manifolds