# Exhaust thermal wrap. is it even worth the money?



## Chuck (Nov 19, 2003)

Just kinda wondering if using exhaust thermal wrap actually keeps under hood temps down? or if its a "urban legend" type thing.. Due to my budget, swain coating isnt that much of an option.. considering swain coating my turbo exhaust side, and manifold would run me about 270$.. and the thermal wrap Full kit would be less than 100$.. or i could just not get it at all. just wondering if it works at all.. ive seen quite a few setups with the wraps.. so im assuming it does..


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## lshadoff (Nov 26, 2002)

The under-hood temp on my car were quite high. I measured the intake air temp (when I had the air filter under the hood) using an OBD-II monitoring program for my laptop. The temp rose from 90 to 126 almost immediately under boost:

http://www.brazosport.edu/~lshadoff/obd2/

I bought a turbo wrap kit from JC Whitney and installed it. It definitely lowered the under-hood temps.

http://www.brazosport.edu/~lshadoff/turbo/twrap.html

Lew


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## Chuck (Nov 19, 2003)

Hmm very interesting, ill probably end up wrapping my manifold, downpipe, and turbo.. keep it cool


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## morepower2 (Apr 19, 2002)

Chuck said:


> Hmm very interesting, ill probably end up wrapping my manifold, downpipe, and turbo.. keep it cool


don't wrap the manifold, it will crack.

Mike


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## Chuck (Nov 19, 2003)

really? how so?


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## morepower2 (Apr 19, 2002)

Chuck said:


> really? how so?


The manifold will get too hot and crack. The downpipe, etc is ok to wrap.

Mike


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## NotAnotherHonda (Aug 7, 2003)

morepower2 said:


> The manifold will get too hot and crack. The downpipe, etc is ok to wrap.
> 
> Mike



yea chuck, you gotta think of it like this- since your keeping the hot air CLOSER to the manifold, therefore, it gets hotter... DUHHHHH!!! haha jk


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## javierb14 (Jul 9, 2002)

i only wrap the mani/dp *if* nearby parts will be affected from the heat....such as the alternator, rad hose, oil return line etc. if you build the mani out of stainless, you really dont need to wrap it. stainless is a pretty good insulator.....it will keep the heat where you want it. you can wrap the downpipe, but it will shorten the materials life. from my experience, wrapped material or parts tends to corrode a lot faster when compared to the unwrapped stuff. i've seen a few stainless dps that where wrapped rust and crack in short time. 

concerning underhood temps and turbo cars.....
the only thing i worry about is the paint on the hood cracking from the heat....but i have a primered hood on my car right now so i dont care  but to prevent this, you can use a reflective lining....looks like insulation for your house but with a shiny surface. you can get it from any hot rod shop or can try and find/make it yourself at any hardware store. then just find a way to attach it underneath your hood.....it works really well. 

if you do decide to wrap something, try soaking the wrap in water before you put it on. you will be less itchy afterwards.


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## morepower2 (Apr 19, 2002)

javierb14 said:


> i only wrap the mani/dp *if* nearby parts will be affected from the heat....such as the alternator, rad hose, oil return line etc. if you build the mani out of stainless, you really dont need to wrap it. stainless is a pretty good insulator.....it will keep the heat where you want it. you can wrap the downpipe, but it will shorten the materials life. from my experience, wrapped material or parts tends to corrode a lot faster when compared to the unwrapped stuff. i've seen a few stainless dps that where wrapped rust and crack in short time.
> 
> concerning underhood temps and turbo cars.....
> the only thing i worry about is the paint on the hood cracking from the heat....but i have a primered hood on my car right now so i dont care  but to prevent this, you can use a reflective lining....looks like insulation for your house but with a shiny surface. you can get it from any hot rod shop or can try and find/make it yourself at any hardware store. then just find a way to attach it underneath your hood.....it works really well.
> ...


If you road race, you'll be surprised what melts due to the turbo under the hood!

Mike


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## javierb14 (Jul 9, 2002)

tru, i bet the underhood temps of a road race car are much higher than a daily driven car. my car only gets _beaten_ on for seconds at time....i imagine road race cars are almost constantly loaded. what fails? have any pics?


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## lshadoff (Nov 26, 2002)

morepower2 said:


> don't wrap the manifold, it will crack.
> 
> Mike


We'll see. Mine has been wrapped since September 2003.

Lew


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## Chuck (Nov 19, 2003)

ok, well explain to me how swain coating is any different.. does it not keep the heat inside the manifold.. which im sure increases heat..


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## morepower2 (Apr 19, 2002)

javierb14 said:


> tru, i bet the underhood temps of a road race car are much higher than a daily driven car. my car only gets _beaten_ on for seconds at time....i imagine road race cars are almost constantly loaded. what fails? have any pics?


I have had the distributor melt even though it was 6" away on Aaron's NPM Sentra, wire harnesses even though 4" away and wrapped with thermotech on a GTR and another turbo SE-R, fan's though a heat shield. Gotta be sorta paranoid on a car that sees track use.

The distributor sagged and tuned into a pile of goo.

Mike


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## morepower2 (Apr 19, 2002)

lshadoff said:


> We'll see. Mine has been wrapped since September 2003.
> 
> Lew


I think if you ran just a couple of hard track sessions on a track with a long straight, it might crack.

Mike


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## morepower2 (Apr 19, 2002)

Chuck said:


> ok, well explain to me how swain coating is any different.. does it not keep the heat inside the manifold.. which im sure increases heat..


I think swain will tend to increse the chance that a manifold will crack as well. I don't swain turbo exhaust manifolds for this reason.

Mike


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## Chuck (Nov 19, 2003)

I see..


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