Alright, I'm having my headers installed. They are Mac's Mid length Headers! Now the guy thats bolting them on said i need a thermal header wrap..My questions are:

Do any of those that have mid-length or LT's have header wrap...OR if u do where can i find some? Who makes it and How Much $$$?

Thermal Header Wrap- The stuff u wrap ur header to keep wires and such from melting when in contact.. If u didn't know what i was talkin about



Thanks

 

you don't need it...i'd say maybe <1% of the people on this board have it...the dude just wants more money

 

A street car doesn't need header wrap.

 

is your headers coated?

 

MACs work plenty good WITHOUT header wrap...

 

You Do Not Need Header Wrap!!!!!!

 

yeah they are ceramic coated, so i take it i dont need em

 

so let me get this straight, there are no wires in the way of the headers? Nothing that's gunna cause problems if it touches the headers?

 

All your wires should clear just fine. I don't know why they would tell you to wrap them. Wrapping headers especially on a street car will make them alot more prone to cracking.

If anything you would want to put a thermal shield around any wires or lines that where close, not on the headers themselves.

 

I am going to wrap the collector area of my long tubes around the 02 sensor bung. I'm not going to wrap the whole set though, but it DOES keep underhood temps down.

The only thing is, the stuff is expensive. DEI makes it FWIW.

 

You don't really need it. I had a set of headers on my old Camaro that burned wires after a while, I bought the spark plug wire boots and that stopped it. I guess it will keep your underhood temps down, I have Jet Hot coated headers and it is a lot cooler under there now, pluse 10 minutes after i shut it off I can touch the headers!!!

 

Weird, I remember hearing that Header wrap was awful for street cars. (thirdgen.org)

 

The main reason for header wrap is to keep the heat in the pipes so the exaust remains hot and continues to expand forcing it down the pipes, with a side benefit of keeping underhood temperatures down. If you have wires that you are concerned about wrap them with heat shield. DEI makes all kinds of thermal products and several of our sponsors carry them. If your headers are coated you don't need heat wrap, but you may have some wires that you want to wrap to protect them.

 

Right. I'm using the header wrap on my fuel lines when I do my duals, and the reason i'm wrapping the collectors on my long tubes is because I want to keep the heat in the tubes to keep the O2's heated correctly. Too often I see people with odd idling problems, and it seems to be the O2's aren't staying heated correctly or however you might want to exlpain it

 

What do you guys think about the clamp on header sleeves / jackets make by DEI or thermo-tec? They are fastened onto the primaries via metal zip ties. I would think that more heat is lost via the primaries than it is by the collector because of the larger surface area. Besides, wrapping the collectors has the potential to soak up water and salt from the road, which may will contribute to header rot. I may have to try those header sleeves though since I keep throwing insufficient codes, and I dont think i can just keep replacing my o2s ever few weeks during the winter months.

-Tony

 

Well, you could try those sleeves and see how they work. The problem with the O2's is that they moved downstream, so the heat just isn't so great when it gets to them. But the primaries will still be hot no matter what, and wrapping the collector area should usually be just enough.

As far as water soaking into the wrap... thing about how hot that stuff gets. The water will evaporate very quickly.

 

Not to challenge the teacher / pupil relationship here, but I do want to bring a couple issues up if for nothing more than food for thought.

While the primaries will still be hot, its is still where the exhaust gasses will lose the most heat. For instance at work, ill get my buddy a cup of coffee while im in the cafeteria, but i usually eat my breakfast while Im there, so his coffee tends to cool off. At first glance I want to say that I should wait till im finished before I put milk in it and cool it off further, but this is actually incorrect. If I put milk in the coffee before i sit down to eat, the coffee as a whole is now at a lesser temperateure differential to the outside air, meaning it will lose heat at a slower rate than if I had kept the coffee hot. Make sense? Now lets apply this to headers. The exhaust gas stands to lose the most heat where the temperature differential is greatest. Thats right at the primaries, where the temps are hottest.

To go one step further, the added surface area lets heat escape the primaries faster as well. The combined total surface area of the primaries is 22 sq. in. per linear inch, whereat the collector's surface area is only 9.4 sq. in. The more than double the surface area has an effect not unlike a heatsink that bleeds exhaust temps into the surrounding air.

Also, you are quite correct that water should evaporate quite quickly should it hit some header wrap on the collectors. The sticky situation, especially here in the northeastern states, is salt water leaving a salt residue. Puddles of thawed snow and road salt could splash up onto the wrap and the water will instantly evaporate, but the salt remains. Next time its a rainy sunday and your car just sits in the driveway, the moisture in the air could help that salt go to town rotting your collectors away. Im not saying that the primaries are not succeptible to this, but they are positioned in a well protected area. Im not even saying that this is a definate thing that will happen... Its just food for thought.

I was originally going to wrap just the collectors like you are planning, but after thinking about it a little bit, i think id like to try the primaries first. If you do wrap the collectors, you might want to try some of that silicon sealer, which forms a hard barrier surface, that way water dosnt actually soak into the wrap.

-Tony

 

GuitsBoy - good points.