Cheap exhaust trick

[Naito]

friend sent this over to me, your thoughts on plausability?

http://www.corolland.com/performance.html

"One cheap way to get extra power and fuel economy is to wrap your exhaust manifold/header with heat resistant exhaust wrap/tape.

"When exhaust gases are pushed out of your cylinders to your exhaust manifold, the air surrounding the manifold begin to cool the gases. This cooling process reduces the velocity of the escaping gases and the engine must 'work' to push the gases through your exhaust system.

"Wrapping the exhaust headers with exhaust wrap maintains hotter exhaust gases that exit the system faster through decreased density. Increased exhaust scavenging is produced, along with lower underhood and intake temperatures. I would also venture to guess that my catalytic converter operates more efficiently since hotter gases would elevate burning of pollutants.

"I purchased the exhaust wrap by a company called Thermo Tec from a JC Whitney catalog for around $30. I installed the wrap on the header and a portion of the exhaust pipe leading from the catalytic converter to the muffler.

"This mild enhancement resulted in a 5 - 7 HP gain ... the power surge starts at around 3,000 rpm. I haven't had the chance to monitor the fuel economy gains."

[ractive_roLLa]

yeah i thought about wrapping my headers.. but.. wouldn't it cause the header to rust much faster?

[Ratko]

It would actually help prevent rust because it would keep the surface of the header protected from dirt and salts.

However, the most likely case in this situation would be the header cracking from the excessive heat, which is not uncommon.

[Xevuhtess7]

what is that professional stuff you guys used made of? perhaps i could put together some of my own stuff, ghetto style

[Ratko]

Originally posted by rezzle
Cracking actually happens due to extreme temp. changes (like washing the thing when the engine is hot) insulalating the header will acually help that. I am curious though. If it adds HP and reduces emissions and is so cheap and easy don't you think all manufacturers would be doing it?

Not only that, but the amount of time the gases are acually in the header before they move into the exhaust pipe is very small. Someone could try this and Dyno before and after but my guess is maybe 1/2 HP at best with a stock exhaust.

They do, but they do it in a cheap cost-effective way = heat shields

Which are shit... i dont think robots can thermal wrap exhaust manifolds or exhaust piping yet, so i think the manufacturers are gonna stick with heat shielding.

[Chris Corolla S]

I've thought about doing that.... makes sense to me.

[BenG]

Originally posted by Ratko

However, the most likely case in this situation would be the header cracking from the excessive heat, which is not uncommon.

Would aftermarket headers be just as prone to cracking as the stock headers? I don't know if they are made from a different metal or thickness, so it's just a question....

[Ratko]

Originally posted by BenG


Would aftermarket headers be just as prone to cracking as the stock headers? I don't know if they are made from a different metal or thickness, so it's just a question....

Yep.

[arcasmachineracing]

Ratko, living in extreme - outdoor tempatures (like I do in AZ) (ie. 110 degrees F +) would me that I would prob. crack before most, right? How likely / quickly can the cracking occour...

[BLUEMEANIE]

I dunno about gainning 5-7 hp from thermal wrapping... It looks cool tho.
I wrapped the block huggers on my Vette last month, didnt notice a power gain at all.
...then again 5-7hp on top of 550 to the ground is negligible.

[Chris Corolla S]

Hey BM, I though you sold your Vette to buy your fiance that rock?

[NOTSOFAST]

What kind of material to use for wrapping ??

[Chris Corolla S]

From above:
"I purchased the exhaust wrap by a company called Thermo Tec from a JC Whitney catalog for around $30."

I have seen this stuff in JC Whitney myself, they just call it exhaust wrap or thermal exhaust tape or something along those lines...

[Xevuhtess7]

we already saw where he bought it, but we want to know what it is made of.... so that we could make our own rather then buy it

[88 LE]

Originally posted by Xevuhtess7
we already saw where he bought it, but we want to know what it is made of....

Not sure whats its made of.

http://www.thermotec.com/products/full/11001/11001.html

so that we could make our own rather then buy it

Quit being boro and just buy the stuff.