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Exhaust Wrap
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isuras2  



Joined: 17 Jun 2005
Posts: 458
Location: Phoenix, AZ

PostPosted: Sat Mar 04, 2006 11:29 am    Post subject: Exhaust Wrap Reply with quote

Does anybody wrap their exhaust manifold to reduce heat transfer? I just want to know if it is a good idea.

Thanks,
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Kenodog  



Joined: 25 Jun 2003
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Location: Vancouver,B.C.

PostPosted: Sat Mar 04, 2006 12:13 pm    Post subject: Reply with quote

I wrapped my 931 manifold and it reduced underhood temps by ALOT.Everyone said not to as our moist climate would rot it to pieces but that simply isn't the case.The fibreglass wrap does not hold moisture when dry and will be bone dry once it cools despite what little road spray gets on it.Bottom line,good idea.
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isuras2  



Joined: 17 Jun 2005
Posts: 458
Location: Phoenix, AZ

PostPosted: Sat Mar 04, 2006 1:12 pm    Post subject: Reply with quote

Which wrap did you use?
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Raceboy  



Joined: 01 Mar 2004
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Location: Estonia, Europe

PostPosted: Sat Mar 04, 2006 2:33 pm    Post subject: Reply with quote

Kenodog, 931 manifold is very weird shape, any specific instructions how to do this?
I thought about it too, but seeing it, I located a shop were they could coat it with ceramics. But, I heard from our local Supra-tooners that tape is better heat sealer.
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924RACR  



Joined: 29 Jul 2001
Posts: 8325
Location: Royal Oak, MI, USA

PostPosted: Sat Mar 04, 2006 11:28 pm    Post subject: Reply with quote

The header on my racecar is ceramic-coated; I wrapped it besides to reduce heat transfer. I used the header wrap from DEI, with the spray sealant to protect against moisture. Racer Parts Wholesale sells these:
http://www.racerpartswholesale.com/pdfs/pg60.pdf

Here's the end result:
http://vaughanscott.com/after_crash/repair%20progress.htm - scroll down to motor pics


My biggest aggravation with it is scraping the tape off the bottom of the header when I go off-roading.
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924RACR  



Joined: 29 Jul 2001
Posts: 8325
Location: Royal Oak, MI, USA

PostPosted: Sat Mar 04, 2006 11:29 pm    Post subject: Reply with quote

BTW - the wrap is best secured with hose clamps and safety wire. You need to soak it in water to get it to flex properly.
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Kenodog  



Joined: 25 Jun 2003
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Location: Vancouver,B.C.

PostPosted: Sun Mar 05, 2006 5:49 am    Post subject: Reply with quote

I used the DEI 1" wide wrap.You have to kinda start at one end and snake it through the gaps between the mounting bolts.Then use stainless steel lock wire to hold the whole mess together.Mine didn't come out nearly as nice as 924RACR's but it covered about 95%.You'll need to cut little 10-12" pcs. and run them lengthwise as well.Use your imagination.
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Raceboy  



Joined: 01 Mar 2004
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Location: Estonia, Europe

PostPosted: Sun Mar 05, 2006 7:02 am    Post subject: Reply with quote

I have covered 924 N/A stock manifold with wrap tape, I know the technique (moisturing it before, clamping etc) but wasn't very confident doing it on 931 manifold.
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Andrew NZ  



Joined: 22 Jun 2004
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PostPosted: Sun Mar 05, 2006 4:03 pm    Post subject: Reply with quote

I've done my whole exhaust back to behind the seats this weekend, and it's made a big diference to engine AND interior temps.
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J1NX3D  



Joined: 06 Feb 2003
Posts: 1333
Location: New Zealand

PostPosted: Sun Mar 05, 2006 4:49 pm    Post subject: Reply with quote

Andrew NZ wrote:
I've done my whole exhaust back to behind the seats this weekend, and it's made a big diference to engine AND interior temps.


awesome!!!
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Khal  



Joined: 26 Sep 2003
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Location: Sunny and lovely interior BC, Canada

PostPosted: Sun Mar 05, 2006 5:01 pm    Post subject: Reply with quote

J1NX3D wrote:
awesome!!!


Yeah.

And after seeing 924RACR's pic's (looks fantastic, BTW) I think to myself, "Why the f*** didn't I do that while my head was out?!"

Oh well, too late now.
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timstar92404  



Joined: 22 Sep 2004
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Location: richmond BC

PostPosted: Mon Mar 06, 2006 12:18 pm    Post subject: Reply with quote

won't the exhauast manifold melt and crack with super high temperatures... I've heard wrapping your exhaust is a bad idea.
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Lizard  



Joined: 03 Nov 2002
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Location: Abbotsford BC. Canada

PostPosted: Mon Mar 06, 2006 3:05 pm    Post subject: Reply with quote

timstar92404 wrote:
won't the exhauast manifold melt and crack with super high temperatures... I've heard wrapping your exhaust is a bad idea.


the exhaust temps are no where near hot enough to melt your manifold or exhaust if they were then your valves would melt first.

and metal is more likely to break from being cooled to fast. by wrapping the manifold it keeps the heat in and it cools slower and more evenly. thus preventing cracking.
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timstar92404  



Joined: 22 Sep 2004
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Location: richmond BC

PostPosted: Mon Mar 06, 2006 3:30 pm    Post subject: Reply with quote

from what I heard wrapping the header will cause it to glow red underneath... it'll cool down slower but it will be way hotter than without the wrap. But yeah metal expanding and cooling down is what causes it to crack.

all the companies that sell headers/ exhaust parts say that its not recommended to wrap your exhaust... and its against the warranty.
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Lizard  



Joined: 03 Nov 2002
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Location: Abbotsford BC. Canada

PostPosted: Mon Mar 06, 2006 4:44 pm    Post subject: Reply with quote

I call bull on that one,

it will only be red if you have issues with your air fuel mix and timing, otherwise it will get hot yes, but it will cooling more gradual and therefor less prone to cracking.
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