924Board.org

isuras2 · Joined: 17 Jun 2005 Posts: 458 Location: Phoenix, AZ

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

Thanks,
_________________
Rob
'80 931 (sold)
'80 924 NA (sold)
Former Omaha Crew

Kenodog · Joined: 25 Jun 2003 Posts: 2669 Location: Vancouver,B.C.

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.
_________________
1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140

isuras2 · Joined: 17 Jun 2005 Posts: 458 Location: Phoenix, AZ

Which wrap did you use?
_________________
Rob
'80 931 (sold)
'80 924 NA (sold)
Former Omaha Crew

Raceboy · Joined: 01 Mar 2004 Posts: 2327 Location: Estonia, Europe

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.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold

'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

924RACR · Posted: Sat Mar 04, 2006 11:28 pm Post subject:

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.

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

924RACR · Posted: Sat Mar 04, 2006 11:29 pm Post subject:

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.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Kenodog · Joined: 25 Jun 2003 Posts: 2669 Location: Vancouver,B.C.

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.
_________________
1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140

Raceboy · Joined: 01 Mar 2004 Posts: 2327 Location: Estonia, Europe

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.
_________________
'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold

'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

Andrew NZ · Joined: 22 Jun 2004 Posts: 744 Location: New Zealand

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.
_________________
Andrew
1977 RX924 race car
12a bridgeport supercharged
www.race4-dcup.co.nz

J1NX3D · Joined: 06 Feb 2003 Posts: 1333 Location: New Zealand

Khal · Posted: Sun Mar 05, 2006 5:01 pm Post subject:

timstar92404 · Joined: 22 Sep 2004 Posts: 2075 Location: richmond BC

won't the exhauast manifold melt and crack with super high temperatures... I've heard wrapping your exhaust is a bad idea.
_________________
78 924 sold.
85.5 944

Lizard · Posted: Mon Mar 06, 2006 3:05 pm Post subject:

timstar92404 · Joined: 22 Sep 2004 Posts: 2075 Location: richmond BC

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.
_________________
78 924 sold.
85.5 944

Lizard · Posted: Mon Mar 06, 2006 4:44 pm Post subject:

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.
_________________
3 928s,