exhaust wrap

[svobrown]

Exhaust wrap. I search and did not find anything.
I say that it will cool the temp down in the car but could it cause more problems like over heat and stress to the turbo.
Plans are to wrap the down pipe and maybe the turbo itself.
I will be wraping the ic pipe also to keep heat of of them.
Any one done this and did it help?

[Pat_in_L.A.]

It helps in several ways. It isolates the heat, as well as serving as a humidity trap. Any ferrous tubes will rust away a lot sooner when wrapped unless they are ceramic coated beforehand.

[NY eric]

so you are saying

My new downpipe is going to rot now. you have a way of ruining my weekend pat. OK it is your turn to buy.

[Ken Potter]

This is one of those subjects that can have many different pros and cons. One of the products I used to produce here at work were turbo and exhaust tube covers for a company called NABI ( North American Bus Industries ). They supply commuter buses to just about every major city in the US. While turbo / exhaust covers do reduce under hood heat extending the life of all the hoses, wiring, and other heat sensitive components they can literally cook your turbo. Since these were city buses that ran 24 hours a day they were maintained regularly with oil changes and other preventive maintenenace programs. My preference would be a good ceramic coating like Jet Hot or something similar. I think it would also be really only beneficial to a full race car that would be more maintained than a street car. I could go on but it's almost time to GO HOME!!!

[Pat_in_L.A.]

Yup, Ken.

We run that fiberglass/kevlar wrap on the street sweepers so the hydraulic lines don't get cooked. The rotted out pipes are changed much more often than your average highway hauler. But hey, it's steady work!

Eric. I thought it was YOUR turn to buy.

[65ShelbyClone]

Please forgive me for bringing this long dead thread back, but I figure it might save the casual passer-by from having to search this one time....

I personally would not wrap the turbo housing itself, but the downpipe yes. Even then, I would only wrap exhaust to keep the heat from wrecking stuff under the hood, not for performance. I had a '91 Civic with a header(mild steel, BTW) that I had to wrap to keep the A/C lines from melting. After about 18,000mi, it was in better shape than if I had left it open. No rust, no cracking. Smog came around and I had to remove it, though. If the parts get hot enough to glow, you risk thermal cracking anyway.

[Millertime2]

I'll tell you this, I just started my new turbo/header combo today that is wrapped with DEI header wrap. It smoked a ton at first, then stopped after about 5 minutes or so.

[NavySVO]

I personally would not wrap the turbo housing itself, .

Actually, keeping the heat in the turbo will improve it's performance. Keeping the thermal energy (which is actually what the turbo works on) inside the scroll will benifit you.

[NY eric]

Actually, keeping the heat in the turbo will improve it's performance. Keeping the thermal energy (which is actually what the turbo works on) inside the scroll will benifit you.

Yes but on the T3 it is more prone to cracking the ehaust housing.

E

[under pressure]

The cracking of the exhaust wastegate is probably caused by rapid cooling while hot or rapid heating when it's stone cold. I used the wrap before on the down pipe about 4 ft. NavySVO is correct about the enhanced benifits of keeping the exhaust pipe hot. Faster exhaust flow. It was difficult to keep the wrap on good.

[65ShelbyClone]

Actually, keeping the heat in the turbo will improve it's performance. Keeping the thermal energy (which is actually what the turbo works on) inside the scroll will benifit you.

Thats true, but I'm willing to sacrifice the insignificant gain in response for a longer lasting housing and/or manifold. The most I would do on the hot side is shielding against radiant heat. I would make an exception with a tubular header, though, due to greatly increased surface area. I would also just plan on it eventually cracking too.

[NavySVO]

Thats true, but I'm willing to sacrifice the insignificant gain in response for a longer lasting housing and/or manifold. The most I would do on the hot side is shielding against radiant heat. I would make an exception with a tubular header, though, due to greatly increased surface area. I would also just plan on it eventually cracking too.

The turbine actually works more off of the heat of the exhaust than the velocity of the exhaust............it's a thermal-to-mechanical energy transition.
The heat shielding is affective for the engine compartment though.

[65ShelbyClone]

You're absolutely right. I just think that the gain isn't worth potentially cracking a housing or manifold. They don't seem to need the help. If it was proven that wrapping them slowed the cooling process and somehow reduced cracking, I'd change my tune in a hurry. In a race situation where parts are frequently replaced as preventative maintenance, I wouldn't worry so much.

Just my opinion, anyway.

[Wizard191]

If it was proven that wrapping them slowed the cooling process and somehow reduced cracking, I'd change my tune in a hurry.

Wrap does slow the cooling process. The only way for the heating or cooling process to change in rate is by changing the overall heat transfer coefficient of the materials involved (which would be the steel housing, and wrap, if present). This can be changed in two ways, first the material is changed so the conductivity constant is changed, but that's not really possible in this application. The second way would be to create a "thermal series curcuit"; AKA add insulation. When wrapping the housing there are actually two layers of insulation added, because the air in between the wrap and the housing acts as insulation (actually a very good one). The overall heat tranfer coefficent is then the sum of the insulators. This means that it takes longer for the turbo housing to cool (and this also means that it heats up faster).

If you are really looking for the greatest increase in efficiency, plus not have to worry about corrosion, then you should get the housing and downpipe ceramic coated on the inside and outside and then use wrap. Ceramic has wonderful insulating characteristics. Not only that but it's hard as a rock (litterally ) and will seal out the moisture that forms under wrap. Moreover, sealing the inside of the housing helps with the heat stress from a quick heat-up, which a thermal wrap won't protect from.

HTH,
Dustin