Ive recently wrapped my downpipe and made a heatshield which has knocked my ACT's down a good 15-20 degrees about town.

Is there any reason not to wrap the exhaust manifold??

 

are 4x4 manifolds not prone to cracking?
imo wrapping it would make even more prone to cracking as your keeping the heat in it

 

are they that bad???

 

hmm i wouldnt mind knowing this too, I was going to wrap mine but i didnt know about the cracking problems?

 

surely cracks are from expansion and contraction yes?

then surely contraction would be less if the heat was kept in when wrapped?

Chip or someone else with more of a pulsating brain got any input, id be interested to see if my theory was utter horse crap or some legitemacy in there

 

the cracking is always at the same point on the wall/ webbing opposite the mouth on the entrance to the turbo, it has to be the heat generated at the small area causing it.

steve

 

interesting, ive never owned a 4x4 manifold, let alone a cracked one so never seen this, but principles for most manifolds agree steve,

all Audi 5 pot manifolds ive had to change, 4 so far, have all gone in the same place on my A4, again just before the entrance mouth!

 

I wrapped the exhaust manifold on my turbo ZX10R engine using Thermo-Tec Generation II Copper wrap and it has gone all dry and brittle and began to fall off, after only a few hundred miles, not overly impressed with that! Although the downpipe/exhaust are still fine.

It worked wonders for the under bonnet temps though, the wrap felt like a household central heating radiator when the engine etc was at full temperature.

 

Have you checked there isn't a silicone hardener for the wrap that your supposed to use? The dei stuff usually does.

 

I used this wrap



and coated it with this once it was wrapped onto the exhaust/manifold



The finished article before it dried out, went brittle and began to fall off on its own



This is the exhaust, which is still in perfect condition



Feel free to give any more feedback

 

You've used the right stuff it looks like you didn't saturate the manifold enough as its got multiple layers. The only reason I say that is that you can see the colour of the wrap.

And did you wet it before you fitted it? With the normal stuff you can lay it tighter if you wet it first.

Very neat tho I can never get it to look neat

 

I used cheap shitty wrap and a can of hi temp paint on my 2wd manifold.
It did wonders for underbonnet temps, you could actually hold the manifold after a run whereas before if you looked at it it would burn you.
It was on there for a couple of years and didnt crack, it did start to perish so i took it off and had the manifold ceramic coated inside and out.
This is nowhere near as good in my car so i will be re wrapping it with carbon wrap.

I did also wrap my whole exhaust system up to the back boxes with the same stuff, this didnt perish but did cause the exhaust to crack on a Y join, where it split fom 1 to 2 pipes on the sharpest point it cracked.
I will redo this aswell and not sure what i will do with that section as it will just crack again.