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Discussion Starter #1 (Edited)
I’m posting this to help those who want to put insulation on their header but have been scared to do it because of the horror stories about wrap and header life. I put this here because it doesn’t belong stuck in a GD exhaust forum. It’s certainly does not belong in the GR exhaust forum, and not in the DIY forum. I’m not writing instructions.



Header Wrap - should I? - Will it damage my header? - How long will it last?


When I planned my current cars build in 2015 I was as concerned about everything and hesitant about many things, power, ringland issues, bearings, header and header wrap and many, many more things.

I was concerned about lower quality brands header life. I was more concerned about life of a wrapped header. Over the years I have become very confident that IAG advice and my choices were good. I ended up having an inexpensive header wrapped with DEI-Ti. I did learn how to be meticulous about not getting oil on the wrap. Back then I worked outside on ramps. The most important thing besides being careful was not to change my oil in windy conditions. That worked out well, and I inspect for other leaks when I change my oil too. This post documents my header and wrap experience.

Last spring summer, after 4 years and nearing 50K mi my wrap started coming off and I got around to re-wrapping it latter last summer (2019). I was prepared to find a thin weak, cracked or otherwise unusable header. When I removed the header I learned it was a Tomei Expreme which I hadn’t even known! I am quite happy with it. The wrap lasted longer than expected and the header is in great shape. Again this post is mostly to info available to allay others fears about getting great performance. You can find my arguments about over whether to wrap or not in terms of performance on this site.

Getting header off was easy, but in doing it I damaged the wrap on the up-pipe. It really needed to be replaced too an it was very fragile. Getting it off and was not so easy. At the top, Intercooler, AOS, heat shield and waste gate bracket all came out. At the bottom my DP was already off (cause I’d pulled the transmission to have it rebuilt) but my waste gate had to come-out and left side of the engine was raised to fit the flange out.

Here are the pics:

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Discussion Starter #2 (Edited)
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Excellent post and great write up with pics!

I’m nearly in the same situation except I have neither the space, expertise or skill to hav me done it myself!

original owner of my GDand have had the Tomei EL headers for ~ 10 years now. They were wrapped originally and, like you, the header wrap eventually failed due to time, weather, and I’m sure many many heat cycles
On my second set of wraps, now DEI lava wrap (I think)? Might be same as the titanium.
Either way, agreed that I’ve had many years of good service from my Tomei headers and they’ve been wrapped the entire time too!
 

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How long a header lasts when wrapped depends on many factors. Making blanket statements on wrap and longevity is not something I would recommend as it can have poor consequences for some.

It's great that you guys have had good luck with wrap, but some google searching will find many others have not. The unwrapped header pics above look horrible IMO. Surface oxidation and severe corrosion have occurred to the point where there is visual pitting of the material. If you take a cross section where the material that has been removed from pitting it has left a thinner tube wall. Now that may mean it last another 10 years or 10 days it depends on your luck. One thing is certain, the tubing strength is decreased when material is removed from it. Overwrapping can also embrittle the metal. This is observed as carbon precipitation happens, leaving a black flaky texture on the surface.

You might think I have a poor opinion of wrap, but that would be incorrect. It has it's place. We only recommend it for non-daily applications, good weather only, or racing. Although, if budget and time permits we always recommend a high quality coating (we use and recommend Swain Tech Multi-Layer Ceramic Coating, as it performs as well as any wrap and lasts far longer). The really big benefit of a coating is that nearly no degradation of the material occurs because the metal is shielded from oxygen, water, salt, oil and other auto related fluids. A good coating will also last many times longer than any wrap and is usually unharmed by fluids.
 

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Nice write up! Its nice to actually see a positive post about topics like this. I havent really found any direct or definite answer to if a header will crack after prolonged use with a wrap or even a heat coating. There are many pros and cons to both wrapping and coating headers. I find that the people that the expierence the failures wheater theirs is wrapped or coated, blow it out of proportion. For 10yrs of wrapped use, that header looks to be in decent shape. Do you run an undershield or something like that under the car?

I personally am not a fan of the heat wrap for the specific reason that its potential hazard if anything were to get on it. Also many years ago, i tried wrapping my oldschool oem GS PnP headers and cross pipe with that DEI-TI wrap. Needless to stay, i was not successfull whatsoever at doing it and was very itchy after LoL. I scrapped the wrap and left the manifold bare.

Personally, if i had to modd all over again, i would heat coat everything over a wrap.
 

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Discussion Starter #6 (Edited)
Nice write up! Its nice to actually see a positive post about topics like this.
For 10yrs of wrapped use, that header looks to be in decent shape. Do you run an undershield or something like that under the car?
FYI:
It was only 4 years and about 45Kmi of all weather use.

Yes I always have the stock undershield in place. A benefit of wrap is that it works so well you can with little risk of melting the plastic. I never had any ssues with my early release Perrin engine mounts thst a couple members had heat related problems with.

many years ago, i tried wrapping my oldschool oem GS PnP headers and cross pipe with that DEI-TI wrap. Needless to stay, i was not successfull whatsoever at doing it and was very itchy after LoL.
I noted that I was not writing a DIY, but I might have warned to wear gloves and something like a windbreaker to remove old wrap. It is far worse than say home insulation and it gets everywhere. The new wrap is not so bad. thin mechanics gloves work well enough. I should also mention that I am no expert. I am a decent home mechanic with a decent shop. But this was the first time I've pulled the header and the fist time i've ever wrapped one! It's not that difficult. I just spen a few hours doing it carefully.

many years ago, i tried wrapping my oldschool oem GS PnP headers and cross pipe with that DEI-TI wrap. Needless to stay, i was not successfull whatsoever at doing it and was very itchy after LoL. I scrapped the wrap and left the manifold bare.

Personally, if i had to modd all over again, i would heat coat everything over a wrap.
I will not because it doesn't perform it's primary job of overall heat retention nearly as well. I would consider doing both - or Inconel shield.
 

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Discussion Starter #7 (Edited)
How long a header lasts when wrapped depends on many factors. Making blanket statements on wrap and longevity is not something
I am certainly not making a blanket statement. I “tested” one header in quite varying undocumented conditions – for a substantial amount of use.


It's great that you guys have had good luck with wrap, but some google searching will find many others have not.
There’s a lot of junk out there. You might have issues with it/them regardless of wrap. I was not trying to write an add for Tomei. If wrap is as bad as you imply, then perhaps they deserve one.


To be fair, the better your choice of heat retention works, the harder it will be on the whatever your headers material is.


The unwrapped header pics above look horrible IMO. Surface oxidation and severe corrosion have occurred to the point where there is visual pitting of the material. If you take a cross section where the material that has been removed from pitting it has left a thinner tube wall.

I did not mention it, but I took a hammer to header areas that might have been suspect. Thinner and weaker than new? Sure. Will it last another four years and 40K? I’ll give you 2 to 1 odds on it. If it makes it 50K, that will be at the time of this cars retirement. If I not were fairly confident the header would last that long I would have found another - perhaps even one of yours. I would have wrapped it too :)

ADDED: My intent is solely to provide members good information. I pledge to post any header failure here as soon as it might occur regardless of anything else. I am not afraid to admit I am wrong when I am.

Another comment: despite my being very careful about not getting oil on the wrap. When I first had the header and wrap I did not have a garage. I mentioned not changing oil in the wind because I did get small amounts of oil on it. It burns off – just as if it were bare metal. Not sure it’s really an issue for small amounts.
 

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I would stay away from wrapping the header for numerous reasons. the first two being it hold's moisture when it gets wet and will also hold any type of fluid that may get on it.
i have unwrapped a few previous wrapped headers and they were destroyed.
 

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Discussion Starter #9 (Edited)
Again I was fully prepared to replace the header - and if I needed to I would have wrapped again. I want insulation on my pre-turbo exahaust. It's part of making the most of what I wanted/built/have. I dosen't make any less sense than commuting 100mi/day in a built STI - kind of goes with that sensibility.

Perhaps DEI holds less water.
Perhpas Tomei deserves credit

I don't know why. but as terrible and mine looked ( :) :) :) :) ) they will be fine for another four years.


ADDED:
I would stay away from wrapping the header for numerous reasons. the first two being it hold's moisture when it gets wet and will also hold any type of fluid that may get on it.
i have unwrapped a few previous wrapped headers and they were destroyed.
Care to share more detailed info such as header brand, what it was wrapped wit, and if traditional wrap whether it was well coated after wrapping, general use and life that you experienced?
 

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Again I was fully prepared to replace the header - and if I needed to I would have wrapped again. I want insulation on my pre-turbo exahaust. It's part of making the most of what I wanted/built/have. I dosen't make any less sense than commuting 100mi/day in a built STI - kind of goes with that sensibility.

Perhaps DEI holds less water.
Perhpas Tomei deserves credit

I don't know why. but as terrible and mine looked ( :) :) :) :) ) they will be fine for another four years.
I run the same setup. Tomei ELH and DEI wrap. I had it on my old STI for 3 seasons without any degrading. Saw all year use, summer and winter. Had it on my GT350 LT headers for 2 years, no issues. Now it’s on my new STI.


Sent from my iPhone using Tapatalk
 

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pwn n00bs
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Again I was fully prepared to replace the header - and if I needed to I would have wrapped again. I want insulation on my pre-turbo exahaust. It's part of making the most of what I wanted/built/have. I dosen't make any less sense than commuting 100mi/day in a built STI - kind of goes with that sensibility.

Perhaps DEI holds less water.
Perhpas Tomei deserves credit

I don't know why. but as terrible and mine looked ( :) :) :) :) ) they will be fine for another four years.


ADDED:


Care to share more detailed info such as header brand, what it was wrapped wit, and if traditional wrap whether it was well coated after wrapping, general use and life that you experienced?
if i could remember, i would LOL.
I do remember one being the older perrin units and one being an ebay replica of a gt spec and one being an hks.
then i wrapped my own header and looked it after a few years, which was a gt spec. i was not a fan...not a fan at all. now a downpipe, i would wrap.

but i really hate wrap. when it gets toast, it falls apart and those fibers go everywhere. i know technology has changed since then, the titanium wrap is nicer.
 

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^ That's a good point. If we were talking about the downpipe, I am all for wrap. They tend to be just below the temperature where oxidation occurs.
 
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