Wrap header?

[Ataim]

I'm fixing to put a new header on white (93 with 1.8L motor). Should I wrap the header with that stuff or not? Does it help or not.
http://cgi.ebay.com/ebaymotors/Exhau...12702393QQrdZ1

[Miatamoto]

I'm fixing to put a new header on white (93 with 1.8L motor). Should I wrap the header with that stuff or not? Does it help or not.
http://cgi.ebay.com/ebaymotors/Exhau...12702393QQrdZ1

I think it works, but some people say that it will promote corrosion on the header. I'm running a Track Dog header blanket on my car. There is an obvious difference in under hood temps, but I don't know how much HP it equates to.

[Machismo]

If it is stainless, the only corrosion would be from dissimilar metals (Block to the header). So even without the wrap, corrosion might be a factor. Always a good idea to fight off the temps with wrapping.

[Magma]

Hopefully Nexus Flux will chime in but we wrapped my DP with something similar and I also have the TDR "blanket" that works well for me too

[johnwag]

Bo wrapped my header when we put it on back in September.
I have heard mixed opinions about how it is better for cooling to unwrap it and better for heat retention if it is wrapped. I'm not really sure any more......

[Nexus Flux]

I have used the DEI exhaust wrap in the past. We installed it on Magma's DP and I'll be putting it on the rest of my exhaust soon. Also I had it on my old car and I haven't noticed any increase in corrosion over non wrapping.

The wrap keeps in more heat but it does get warm. So if it gets wet it will dry out very quickly. To make it easier to wrap tightly, wet the wrap in some water. Elliots carries the stainless steel zip ties to install it. (cheaper than Summit) After you put it on and let it dry, spray it with some VHT paint to help protect it and increase it's resitance to getting wet.

The 1" is easier to put on tight headers and the 2" is good for long sections of pipe. You only have to overlap about 1/4".


The DEI PN are
PART # DESCRIPTION MSRP
010101 Exhaust / Header Wrap 1" x 50' $31.74
010102 Exhaust / Header Wrap 2" x 50' $50.93
010103 Exhaust / Header Wrap 2" x 100' $93.10
010104 Exhaust / Header Wrap 6" x 100' $210.00
010105 Exhaust / Header Wrap 1" x 15' $9.25
010106 Exhaust / Header Wrap 2" x 15' $15.47
010107 Exhaust / Header Wrap 1"x 50' - Black $34.37
010108 Exhaust / Header Wrap 2" x 50' - Black $54.98
010120 Exhaust / Header Wrap 1"x 15' - Black $9.97
010121 Exhaust / Header Wrap 2"x 15' - Black $16.08

Let me know if you have ????.

[Ataim]

I'm not really sure any more......

That's how I feel.

Thanks Nexus, I'll order the 1" instead, I mean its going on a MIATA, for goodness sakes. Will 50 feet be enough?

[Titus]

Will 50 feet be enough?

Depends... 4-1 or 4-2-1? What is the length and diameter of each runner?

[black roadster]

I've done this in the past to a header and it corroded a hole in it.

[Nexus Flux]

Check out the chart at the end of the install instructions to help determine how much you will need.

Link to instruction PDF

[Magma]

I've done this in the past to a header and it corroded a hole in it.

that is because if it isn't Chrome of JDm your car rejects it KOB

[black roadster]

that is because if it isn't Chrome of JDm your car rejects it KOB

ha ha...

It was my first car.

[Billy Blaze]

I thought it was one of those items I could do without, but God forbid you have to work on the car if it breaks down and you dont have a heat shield.
The engine temps were so freakin hot you could fry an egg on the hood and under the hood was insanely hot...to me just lowering the temps under the hood was worth it.
Cant tell any more HP gains but who can with these aftermarket parts without going boost, I would highly reccomend it just for being able to check the oil after running the engine....besides the shiny headers only last about 4 hours anyhow before they turn bluish black.
I am using the TDR version and it works very well.

[MadMerv]

Tube headers (like a Miata) will rust much more quickly if they are wrapped. Wrapping is a good thing for a race car that has plenty of air exraction and will make a bit more HP. Unfortunately, I know of no class of racing Miatas that allows it. For the street, you want all the heat disipation you can get, so don't do it!

[Nexus Flux]

I'm not starting nothing, but I do have a few questions.

...For the street, you want all the heat disipation you can get, so don't do it!

Why would this be desirable? Wouldn't you want lower underhood temps? Also, as exhaust gasses cool they contract and take up less volume, thereby also loosing velocity. If they are kept hot, exhaust gas velocity can be kept high thereby helping to maximize the scavanging effect of the mainifold.

I can see that wrapping headers might not be allowed in race car enviroments due to their prolonged high reving. The manifolds could develop hot spots and possibly break at the welds, which could also happen due to poor fabrication and welding techniques. Also for race officials it is much easier to check runner diameters if they are not wrapped to make sure they conform to race regulations.

[gabkwong]

Just a question. By wraping th header, do you not keep the exhaust temp high which makes the cat operates at a higher temp and shorten its life?

[Nexus Flux]

I suppose that's possible. What's the normal operating temp of a catalytic converter?


EDIT Here is some info I found on temps:
Modern catalytic converters are not as susceptible to temperature damage, many modern 3-Way platinum based converters can handle temperatures of 900°C (1652°F) sustained, while many modern 3-way palladium based converters can handle temperatures of 925°C (1697°F) sustained.

Also take into consideration that the melting point of stainless steel is around 1400°C (2500°F). Platinum has a melting point of 1769°C (3216°F) and Rhodium melts at 1960°C (3560°F). Platinum and rhodium are used in three way cats.

Now the question is, "How hot are exhaust gasses in our cars?" If the EGT guages on the market are any indication, most don't go past 875°C (1600°F) and only a few go to 1100°C (2000°F).

[Titus]

I suppose that's possible. What's the normal operating temp of a catalytic converter?

From HERE:
The average light off temperature at which the catalytic converter begins to function ranges from 400 to 600 degrees F. The normal operating temperature can range up to 1,200 to 1,600 degrees F. But as the amount of pollutants in the exhaust go up, so does the converter's operating temperature. If the temperature gets up around 2,000 degrees F or higher, several things happen. The aluminum oxide honeycomb begins to degrade and weaken. The platinum and palladium coating on the honeycomb also starts to melt and sink into the ceramic substrate reducing its effect on the exhaust. This accelerates the aging process and causes the converter to lose efficiency.