How hot is the exhaust for exhaust wrap

DohertyCM · DohertyCM's Garage

Just wondering if anyone knew how hot the headers get. I would like to wrap my exhaust and need to know the temp range so I can get the right stuff.
Thanks..

Oh by the way, I have a 2.7 motor if that makes a difference.

Chris

euro911sc · euro911sc's Garage

I just got the stuff they carry at the local speed shop. Worked fine on my turbo 1.8T. I got the 1" width. If I knew then what I do now I would have gone wider...

Best regards,

Michael

DohertyCM · DohertyCM's Garage

I bought the 2 inch wrap some time ago and wrapped the exhaust.
But I ran over a speed bump and ripped the stuff off the bottom.
When taking the rest off to rewrap, i noticed the stuff was like glass.....
So I was thinking that I may have gotten the wrong wrap, and needed to get something else....am I wrong here....so the question remains how hot does it get?

JohnJL · 04-03-2009, 09:06 PM

I'll take her for a spin and shoot the headers with my temp gun tomorrow if the rain lets up...

The right stuff does have glass in it...you want to wear gloves and soak it in warm water when wrapping it.

DohertyCM · DohertyCM's Garage

Thanks for the help.
I have to ask the question becaue there is 500 degree to 2000 degree wraps..
1000 is the most common.
I will remember the water soaking... the first time was a mess.

chris

911pcars · 04-04-2009, 10:40 PM

With an IR temp gauge, I observed about 400ºF at the exhaust pipe section below the lower valve cover. A Thermax temperature strip mounted on the valve cover reached 300+ºF. Turbo engines will have much higher exhaust temperature.

Wrapping the pipes with exhaust wrap may shorten the life of the pipe material due to excess heat. One manufacturer makes a split thermal exhaust sleeve which can be fitted over the sections nearest the engine.

Sherwood

JohnJL · 04-04-2009, 11:22 PM

Sorry Chris, I got caught up in the honeydo list today. I will take the car into work tomorrow, weather permitting.

JohnJL · 04-07-2009, 06:03 PM

I got ~500F at the exhaust flange after a spirited run home and idling for ~60 seconds. I noticed the temps fall quickly while idling.

There shouldnt be a huge difference in cost, I'd go for the 1000F range.

T77911S · 04-08-2009, 03:07 AM

i have wondered about that stuff before. does it help the engine run cooler?

Fast Corners · 04-08-2009, 07:29 AM

I used the wrap on my '67s and found that it did help engine temps slightly. It also has a minor improvement on performance. If the exhaust gasses remain hotter they will not loose as much volume within the exhaust system. Since there is no where to go but out, the larger volume of the gas will result in higher exhaust velocitys and better scavenging effects (assuming proper header design).

I had my recent set of headers for my '73 jet hot coated which was pretty cost effective. I went with the 2000 degree coating just for insurance. The coat both the inside and outside of the headers and supposedly it has a measurable effect on reducing engine temps. I will have to let you know when I get everything together.

MBruns · 04-08-2009, 04:19 PM

On the dyno 2 in. from the ex. gasket its 1200 deg., the real problem with the wrap on a mild steel system is it retains so much heat in the metal that it KILLS the pipes, they will turn to dust in no time. It does help with scavenging and keeping the heat from the engine but unless the system is 308 or 321 stainless alloy like you would have on a turbo car it won't last long. Jet Hot (ceramic) coatings would be a much better way to go.

Mike Bruns JBRacing.com

DohertyCM · DohertyCM's Garage

I noticed that on my bursh headers that i put on and wrapped, the headers started to droop when i was running a DE...

Bummer...but I put a jack on them and bent them back up while they were hot.

Hmmmmm.... how long can I use them like this?

Fast Corners · 04-10-2009, 09:32 AM

DohertyCM,

Are you using a muffler strap? If not, I would use one. The weight of the exhaust system needs to be supported at the tail end as weel as at the ports. I have seen 911s where the strap was omitted develop exhaust leaks, cracked flanges & broken studs.

Just a thought as this may help with the droop.

fastfredracing · 04-10-2009, 02:59 PM

Quote:

Originally Posted by DohertyCM

I noticed that on my bursh headers that i put on and wrapped, the headers started to droop when i was running a DE...

Bummer...but I put a jack on them and bent them back up while they were hot.

Hmmmmm.... how long can I use them like this?

Not only did I have the same problem at the track, I actually had to come in because I smelled smoke, and as soon as I stopped the car, my header wrap caught fire. I had a minor oil leak, and the saturated material sparked up. So my point is, unless you have an absouletely leak free engine, and dont plan on having any leaks, header wrap on a 911 may not be the best idea. Just my 02 cents.
I did however notice lower temps , and less radiant heat in the engine bay.
I also believe that it will also signifigantly reduce mild steel header life, I assume the extra heat retained, and the propensity to hold moisture would be tha cause. A brand new set of aftermarket headers lasted only two seasons, when I unwrapped them, they literally fell apart. looked as if they were 20 years old. The replacement pair I put on have lasted about 7 years now, and still look good.
Hope this helps

DohertyCM · DohertyCM's Garage

I have used them in the rear....but not in the front....
However I have going to as soon as i get it put back together..

I dont know why I didnt do this in the beginning.