Should I be using exhaust wrap?

[silver33]

I recently had a 3" dump fitted and the original heat shield over the turbo and dump was removed.

Should I get some exhaust wrap on the dump?

How effective is exhaust wrap in reducing under bonnet temps?

www.flyn.com.au is selling 6m of fibreglass exhaust wrap for $48. Anybody using this stuff? Is this stuff any good?

[Roy]

Im looking into doing the same thing this coming week fo rmy new dump pipe. An estimate from an exhasut shop was that i would need approx 10m to do a 3" dump pipe. This would allow the dump/front pipe to be covered past the bottom of the firewall.

Add to this the expense of the clips to secure in place, and the coating to protect from the elements and i have decided to get the dump pipe ceramic coated. At approx $80 it is neater and perhaps better value, i cant say which works better as i have never used the exhaust wrap.

I have had my exhaust manifold and exhasut housing done by Competition Coatings and i have been happy with their work.

[Cubes]

How good is the type of coating?

Are you able to place your hand on it for even a slight second?

[slayer_1971]

There was a thread about this a few months ago...from memory it was advised not to use exhaust wrap as water might get trapped underneath the tape and hence start to rust the exhaust....

[Guest RedLineGTR]

you have to prep the pipe first with special paints etc to get it right then it wont rust. Check the search

[predator]

... u only need 6m to cover a dump as well.. not 10m

[Roy]

10mtrs was for dump and front pipe, as the front pipe normaly had a heat shield that goes all the way down to the cat.

My thinking is they are shielded for a reason so want to do the same to be sure that nothing on the firewall/floorpan is damaged by the hot exhaust. (My old R31 used to cook the floorpan as i had the exhuast tucked up nicely to ensure good ground clearance.

With the exhaust housing of the turbine after a 30min drive you can hold your hand about 1" from the housing for about 15sec before things start to get hot, so would seem to be working. I wish i could have tested it with a thermocouple before/after but didnt want to have to take the turbo off after having instaled it as the coating takes about 4-5 days.

[Guest Robo's]

I wouldnt bother wrapping it up, if you have a good cold air system , then its not going to hurt performance.

[Roy]

Anything that helps remove heat from engine bay is worthwhile in my eyes. Things have a tendency to melt when red hot metal is next to them.

[Guest Robo's]

If your running a pod filter, then you would need it for sure.

You ever felt the temperature of your motor? Ouch

[GTS-t VSPEC]

I'd definately recommend wrapping the dump. I'm having mine ceramic coated, then wrapped. The ceramic coating alone is enough to allow you to touch the dump/or exhaust manifold without burning yourself.

The secondary advantage to keeping the heat trapped in the exhaust gasses is that they help spool the turbo quicker:D

[Cubes]

I imagine that it not only allows the turbo to spool quicker but it MAY also reduce back pressure as the gas has a faster velocity hence it gets out of there quicker allowing the motor to breathe a little better in the higher rev's?!?! Maybe...

[GTS-t VSPEC]

Well I've heard talk that if you ceramic coat both the turbo exhaust housing, and the manifold, then you can make about .2sec at the drags. I'm just hoping it will give me a more responsive turbo:D

[Guest Robo's]

So how does heat make the turbo spool quicker?

[Cubes]

It keeps the heat in the pipes therefor the gas velocity is higher. Hence faster. Therefor the turbo spools faster due to the higher velocity gas speed.

[GTS-t VSPEC]

By trapping the heat in the exhaust gases, the air velocity is quicker, and the higher the air velocity the quicker it spins the exhaust wheel:D

[GTS-t VSPEC]

Posted at the same time, but we're basically saying the same thing:D

[Yakuza]

would it crack after awhile because of heat build up after a period of time ?

[GTS-t VSPEC]

Depends what material you use. I have heard of a number of stainless manifold cracking, but usually due to the poor choice in stainless type (there are many type with different compositions). My manifold is made from steam pipe, it has a much greater thermal mass, and therefore isn't prone to cracking like the thin-walled stainless.

[Steve]

I had a 3" dump of mild steel and the engine bay got bloody hot, so hot that I got paranoid so I wrapped it, which made a huge difference to underbonnet temps.

Have now fitted a stainless ceramic coated dump, and I dont think it is quite as cool as the heat wrapped mild steel, so I will be heat wrapping it aswell.

Having higher velocity in the exhaust, apart from spooling up the turbo quicker, can aid in cylinder scavenging. Also increased velocity decreases pressure, and back pressure is not your friend either:)

Bottom line, if it makes the car go faster/harder, its all good. People have been coating and wrapping manifolds/dumps/turbines for a long time for good reason.