exhaust wrap - interesting results

[lindermant]

I installed my Thermo-Tec exhaust wrap this afternoon:

before pic:


getting ready:


my helper (who was too busy working on his ride to offer me any assistance):


end result:


The hope with the wrap is that I can cool the exhaust pipe enough so that I can put a coroplast belly pan and have it cover the exhaust with no worries of burning it to the ground.

I used an IR thermometer and recorded temps that hovered around 190F on the bare exhaust (previous mention of temps in the 160'sF was actually oil pan temp).

After installing the wrap, I took an approx 40 mile r/t drive to get a reading (and to get out of house for a bit). Two interesting things came from my drive...

1. the exhaust wrap puts out a very unique smell - almost like warm apple pie

2. the exhaust temp reading after installing the wrap ~265F
*NOTE: temp reading was taken at little red block on pics above

What? I thought the wrap would provide a lower temp, looks like I was wrong... Guess I'm gonna have to rethink this.

[omgwtfbyobbq]

I think exhaust wrap have a lower specific heat than the metal.

[ZugyNA]

Are you talking about temps on the surface of the wrap or the pipe after it?

[JanGeo]

aaaahh yeahhha the wrap insulates the pipe keeps the car cool around the wrap and increases the temperature for the 02 sensors and cat - may help to increase FE . . .

[zpiloto]

I think this would help FE. Keep us posted of results.

[lindermant]

ZugyNA - I'm talking a temp reading on the wrap itself. I've only ever taken temp readings on the part of the exhaust that I wrapped as it's the lowest point on the front of my car and would potentially come into contact with the coroplast belly pan when I install it.

I'm a bit surprised at the temp delta as I thought this product was supposed to reduce temps. I'll leave it on for this tank - unless I get a subtantial FE gain I'll remove it and think of another option for protecting the belly pan.

JanGeo - on my civic, the cat is mounted directly on the exhaust manifold, and the portion of exhaust tubing that I wrapped is aft of the cat; so I'm not exactly sure if this wrap job has any effect on the cat/02

[JanGeo]

Maybe it is retaining heat after you slow down and take your reading - is the materal heavy or light?

[lindermant]

JG - the material is pretty light and flexible... the product literature says "fiberglass like"

[JanGeo]

Hummm sounds like it is allowing the pipe to get really hot and retains the heat better - it may actually reduce heat in the area but not when you stop - sort of a delayed heating cooling effect. If anything you should have a nice clean rust free pipe and a quick heating cat - maybe too hot if it doesn't get cooled enough. Carbon Fiber that I have I heated with a butane torch 2000 degrees and when it cooled off it was unaffected by the glowing red heating cooling.

[Ryland]

I assume you are useing an infared thermetor? would it be "seeing" thru the fabric wrap, and telling you the temp of the metel under it? I know that to get an acurite reading on some things you need something like a spot of flat black paint, or wrap it with electrical tape, personaly I would check it with my hand, you should be able to tell the difference of 100F with your hand, if/when I doan exaust wrap I would be temped to wrap the fabric insulation with something to reflect radiant heat, like aluminum foil with the shinny side facing the heat source.

[onegammyleg]

Hi lindermant

Be aware that wrapped pipes usualy fail at a much faster rate than unwrapped pipes.
People that turbo v8s or old volkswagen beetles sometiems wrap the long pipes (going from one side of the engine to another) to keep the gasses hot and fast inside the tube.
It works - but within a few thousand k's the pipes have cracked and need replacement.

May no tbe good economy if you factor that in.

[Kraig]

I know a guy that wrapped his cheap carbon steel headers and they had holes in them from heat erosion in a matter of days.

[onegammyleg]

Hiya Kraig

Yeah , normal tubular extractors don't last long at all . but i think that guys ones were already gone anyway. - they should last more than a few days.
Either that or they were prety dodgy in the first place.

[JanGeo]

Exhost pipes do get hot - my BMW pipes exit the heads going forward and bend 180 under the heads to the rear of the bike. If I idle it for a few minutes reving it a little at night the pipes start glowing red hot. Any highway driving with heavy throttle would result in the pipes getting really hot. To keep it cooler you need to shield it from the coroplast with reflective metal and allow air flow around the pipe. Protecting it from water spray will help the pipes last longer however. Remember the warnings about overheating cats if allowed to idle too long starting grass fires etc. The IR temp probe measures radiation from the surface and shiney surfaces will read a little lower than a dark surface but not too much of a difference.

[lindermant]

took the exhaust wrap off today.... $20 and 35 minutes of my time - one of my cheaper automotive "lessons"

[Kraig]

I think they were "Blackjack" headers .... low dollar junk

[red91sit]

Another thing to consider, I've herad exhaust piping traps moisture in there speeding up the oxidation process.

[JanGeo]

I have a hard time believing that moisture will get trapped in something at 700+ degrees - if anything it will protect it from water spray in the rain which is the worse thing for a hot piece of metal. Actually when the tool and die shop heat treats some metals they actually wrap it in stainless steel to keep the oxygen out.

[red91sit]

Originally Posted by JanGeo

I have a hard time believing that moisture will get trapped in something at 700+ degrees - if anything it will protect it from water spray in the rain which is the worse thing for a hot piece of metal. Actually when the tool and die shop heat treats some metals they actually wrap it in stainless steel to keep the oxygen out.

It's only 700+ degrees when it is or has been working. Here is a direct quote from a header manufacturer

Q: Why should I not use header wrap?

A: Wrapping headers should NEVER be done. Wrapping headers will destroy them and there is no header manufacturer that will warranty a wrapped header. The heat wrap will trap moisture or condensation between the header and wrapping causing it to rust. Heat wrap can also destroy any Ceramic Coating. The best way to keep anything from the heat is to wrap the part you want cooler, like starters or fuel lines. Another way is to have them "ceramic" coated.

http://www.tribaltubes.com/faq.htm

BTW, BIG difference between stainless steel, and exhaust wrap. Ceramic coatings would work great for exhausts by keeping in the heat, and protecting them at the same time. Exhaust wrap? No

[JanGeo]

ok that's for headers how about the exhost pipes and is the wrap breathable or not? How about painting them white to reduce the radiated heat?

[red91sit]

Originally Posted by JanGeo

ok that's for headers how about the exhost pipes and is the wrap breathable or not? How about painting them white to reduce the radiated heat?

Why not just coat the exhuast? since your cars still new it will make your exhuast system last WAAY longer than an unprotected one would. There are special coatings available to block heat transfer aswell.

[90CivicStandard]

I have exhaust wrap on my header. Well, the guy I bought the header from had already wrapped it.

It cools it down enough that I can put my hand on it after driving and I don't get burned. I don't know what brand wrap is on my header, but it cools the area around it a ton.

I'm not sure what purpose it serves, if any, but it was free so whatever.

[JanGeo]

Originally Posted by red91sit

Why not just coat the exhuast? since your cars still new it will make your exhuast system last WAAY longer than an unprotected one would. There are special coatings available to block heat transfer aswell.

Header is between the engine and firewall under a heat shield and I don't plan on taking it apart any time soon either - the point of a new car is to not have to take it apart much. Not sure if the coatings will be applyable in the car. I did coat the muffler because it is behind the right rear wheel to try to protect it a little - will have to see how it is doing later this year when I get back in the garage...