Daddy's Girl

I was told that if I wrap my headers with heat wrap that it will increase my horsepower. Has anyone here ever done that? If so what type of results have you seen?

rskrause

It look like hell and I doubt it will do anything at all.

Rich

Daddy's Girl

So I take it from your response you seen some that looked like hell installed? That is interesting--when installed properly it looks like your headers are wrapped with an ace bandage. The physics behind it makes sense, as soon as the exhaust gasses leave the engine they begin to cool and sense cooler gas moves slower than heated gas it takes more power to push it away from the motor than it would if it remained heated longer. I just thought maybe someone had actually done it and had some results to pass on.

AL SS590 M6

Many use ceramic coated headers which do the same thing and look real pretty doing it.

rskrause

Go to the track and see if anyone going fast uses it.

Rich

cnorton

In the era before Jet-Hot and Nitro-plate coated headers became the rage many of us tried using "the wrap" on the headers of our NHRA Stock Eliminator cars. As stated, the theory is sound but I could never see an improvement on the ET slip. The same statement could apply to coated headers as well.

Wrap looked a little better than rusty headers but it wasn't a snap to put on and it needed to be watched to make sure it wasn't coming loose. In the tight areas around spark plugs the wrap exacerbated clearance problems. Some racers reported that the wrap accelerated the rusting of the headers from the inside-out due to the retention of heat but I can't verify that from personal experience. It is a little cheaper than coating.

Coating is a huge cosmetic improvement over a wrap. Coating will last quite a while before it begins to dull. I've never had a coated set of headers rust through and i've run coated headers on various cars for over 15 years.

Good luck,

c

AL SS590 M6

But even with stainless I'd go ceramic coated to keep the under hood temps down.

Injuneer

Header wrap does not "trap moisture". How could anything running at 1000+*F hold moisture? People take the wrap off, and see rust. They assume that's from moisture. It isn't. Its there because the header tube metal temperature is now almost the same as the exhaust gas temperature, due to the insulating properties of the wrap, and the iron in the low-carbon steel they use starts to combine with the oxygen in the air, creating "rust". In addition to an increased rate of oxidation, the welds start to crack from the extreme heating. Mild steel is not intended to operate at 1000*.

Stainless helps, because it resists oxidation, and retains more strength at higher temperatures. But it will rapidly turn black, and has the same excessive heat loss to the engine compartment.

The advantage offered by the cera-metallic coatings, applied to BOTH sides of the tube metal, is the fact that the interior ceramic coating reflects heat back into the exhaust gas, keeping the inside and the outside surfaces of the metal tube cooler = less oxidation and less thermal stress cracking. Mild steel is now adequate for the purpose. My HPC-coated AS&M's are now more than 10 years old, and the only sign of "rust" is little pimples of it where the weld spatter doesn't appear to have been removed before coating. Even where an EGT bung was welded in after the headers were coated, there is minimal rust.

In theory, the higher exhaust gas temperature = higher velocity, increasing the scavenging of exhaust gasses from the cylinder, and helps pull the fresh air charge in, during overlap. But, as evidenced from the statements above from the experienced racers, its hard to measure the benefits in the real world.

cnorton

Good explanation of the dynamics involved, Fred. Knew what I wanted to say but couldn't pull it all together.

c

Injuneer

You take care of the real world, hands-on racing..... I'll take care of the ivory tower theory BS.....