exhaust wrap

[DaveD]

I have bought a 6 branch manifold, which i think is stainless, from JonB (excelent service ) but before i fit it should i wrap it...the sites say increasesd bhp and cooler underbonnet,,,( but definitely less bling) any comments

[kam-325i]

Here we go again !!!

The wrap will help to reduce the temps under the bonnet, BUT WILL NOT INCREASE POWER OUTPUT, its a bit of insulation.

[JimmyC]

I use it on my '61 bug which I used to drag, big motor needs all the help it can to get hot gas out

Exhaust wraps help to retain heat in your exhaust system, which gives a small increase horsepower while reducing radiant heat damage. By wrapping the header and exhaust system it maintains hotter exhaust gases, decreases the density, and allows the exhaust gas to exit the system faster! Greater exhaust scavenging is produced and lowers intake temperatures: that equals more horsepower.

[oguz327]

so is the wrap worth doing then?

[kam-325i]

Well, going by JimmyC''s post, yep, if not just to keep the engine bay temps down...

[astondg]

The wrap may not directly increase power (although I have also heard what JimmyC said and it seems to make sense) but by keeping underbonnet temperatures down it means that the engine can run cooler and breath cooler air (especially if you have a pod filter or something) which will probably lead to a hp increase. It won't be anything big though, I can't see it being more than a couple of hp if you have an unshielded pod filter (maybe pick up a few more when sitting in traffic and stuff but hp isn't really important there). The exhaust is on the opposite side to the intake as well so it might not matter much when you are driving and the air is flowing through.

Aston