performance question

[trem1]

I been asked by my son wether this is worth it or not, he has a hyundai coupe 2.0 petrol which he wants to increase the bhp on (22 year old too much money) anyway he's already put a catback performace exhaust on and has now bought a 4/2/1 manifold so it'll be a full de-cat. The exhaust is stainless steel through-out and someones now suggested to him that the bhp will be increased even more by getting the manifold wrapped working on the principle that keeping the heat in will increase the bhp.

i know lots of you lot have more knowledge than me on things like this so whats your thoughts

[Welly]

Hot gases flow better when the manifold is at a similar temp BUT this wrap stuff has to be fitted with a certain overlap (I think it's 50%) otherwise you can crack the manifold through uneven temps when heating/cooling. Trouble is it's tricky to maintain this overlap in a retrofit situation so likelyhood of failure is high.

I'd say not to bother as it will most likely fall off/disintegrate in our weather and on our roads thus adding to the uneven temperature problem (cracking).

To be honest there's only so much you can squeeze out of a n/a petrol although gas-flowing the head will good

[HimBigChief]

It's easy to wrap a manifold, and pretty cheap too. I kept an even overlap when I did mine (Subaru Legacy up-pipe) and didn't have any problems at all in over 2 years . I've also wrapped the Magnex stainless manifold on the 309. You just need to make sure you dip the wrap in water to make it more pliable and have a lot of metal tie-wraps, also your arms will itch for days afterwards! The wrap itself is only about £20 or so for a massive long roll (enough to do several manifolds) and lets face it, most modified performance cars (not sure on production ones) wrap or ceramic coat the manifold to keep the heat in.

[munfred]

wrapping probably wont make much noticeable difference for day to day driving, but may help with flow, and keeping engine temps down.
As said is a fairly cheap and easy way, but doesnt tend to last.
How about getting the manifold ceramic coated??