is it better or worse 2 wrap up your exhaust manifold in that thermal wrapping that cuts down under bonnet heat, some people tell me its good others tell me not 2 do it just wanna know some other opinions thanks


1200 ute a14 turbo lpg

i reckon, yeh wack a bit on ur exhaust manifold, but dont put it on ur inlet pipes, coz when the air goes through the turbo to get spooled up it heets up, and if u have rap on the inlet pipes the excess heat wont escape. if u get what i mean.

Thermal wrapping is effective however it causes the mild steel of your extractors to weaken. If having lower under bonnet heat is more important than replacing your extractors regularly then it is worth doing.

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How does that happen? I've just wrapped mine .
I have also heard good and bad things about it. One strange thing was when I started it up after wrapping the extractors, heaps of smoke came off as they heated up. I kept telling myself it is made for exhausts aand couldn't catch fire, but there was quite a lot of smoke. And the colour went darker.

While on the subject, has anyone had any trouble with Coby extractors running too close to the floor when using the taller block A15?

The heat is trapped by the wrap around your headers and cooks them and they become brittle and fracture quicker. This isn't a problem in a race car when you are putting a short service life on components. On the up side your carbs and fuel stay cooler but I don't think the ambient is high enough in NZ to cause trouble with unwrapped headers. Re: the Coby extractors I have had to cut the floor pan on two of my coupes to make an extractor box to run the 4 into 2 into 1 extractors I use. They are competition 120Y pipes though - don't think they are Coby's.

The wrap absorbs water and rusts out the extractors.

As for the coby extractors, Yes I have heard that alot of people have had this problem, I am going to get mine made up to suit to solve this problem.

Thermal fatigue. The wraps work too good at retaining heat and the mild steel can't take it.
No personal experience, but I have read about it in a couple of magazines. I have also found that it voids some header manufacturers warrenties.

edit- here is a better expanation
http://www.google.com/url?sa=U&start=6&q=http://archives.dakota-truck.net/9908/2546.html&e=7249

I've run hi-temp wrap on exhaust systems before. I never experienced any thermal fatigue or cracking. They just rusted out quick. who_your_datty is correct, the stuff traps moisture.

Yes, I have had trouble with floor clearance on Coby flows. Actually, it was only the pipe flange that interfered. I got a big hammer and beat the floor up a bit. I also put packers between my homemade 5spd Xmember, and the floor to lower the pipe angle slightly. Another way to get clearance, is to slot the engine mount holes a bit to get the motor to sit lower in the bay.

yeah, I made some new engine mounts that moved the engine back and dropped it a bit lower, as well as spacing the engine xmember down a bit. I had a low gbox xmember which I didn't have clearance problems with, but when I lowered the car the angle from gbox to driveshaft was too big. So I made a new gbox xmember to raise the gbox until the engine sits about right. Now the extarctors have about 3mm clearance above the collector. At least they're wrapped!
All in all it was probably quite a lot of work for SFA!