Heat wrap downpipes - pros and cons

[kebabman]

So I’ve got a set of APR downpipes to fit to my RS7, and one thing I always notice about this car is the sheer amount of heat that accumulates in the engine bay, even after relatively short drives often it’s so hot it’s hard to even remove the engine cover without gloves. So I was thinking before I fit the downpipes maybe I could reduce some of this engine bay heat by heat wrapping the downpipes, are there any downsides?

I’ve read about the nasty fiberglass fibers when wrapping, the bad smell at the beginning as the wrap gets cooked, and the fact that the wrap can actually shorten the life of the downpipes by trapping water and salt in contact with downpipes. I can cope with the fibers during fitting and the smell (as long as it goes way after a while), and I would mitigate the water/salt problem by spraying it with high heat silicon spray coating after wrapping.

Any other downsides or reasons not to do this that I’ve missed? Will it have the desired effect of reducing engine bay temps by a noticeable amount? Any other pros I might not have thought about? I don’t want to go to the effort of wrapping and spraying the downpipes if I get no appreciable benefit (not bothered about the aesthetics).

I plan to use this wrap: https://www.amazon.com/dp/B002R4U7G4..._CogaDbH1FAT4F

And this silicon spray coating: https://www.amazon.com/dp/B000MY3ML8..._CqgaDb0KV9P2R

[MolonLabe300]

I used this and was happy with the outcome.
https://www.heatshieldproducts.com/i...hield-products

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[Dasquade]

I actually used the exhaust metal insulation heatshield armor on my dp's/hotside turbo/manifolds:
https://www.heatshieldproducts.com/heatshield-armor

[mintytoo]

So I’ve got a set of APR downpipes to fit to my RS7, and one thing I always notice about this car is the sheer amount of heat that accumulates in the engine bay, even after relatively short drives often it’s so hot it’s hard to even remove the engine cover without gloves. So I was thinking before I fit the downpipes maybe I could reduce some of this engine bay heat by heat wrapping the downpipes, are there any downsides?

I’ve read about the nasty fiberglass fibers when wrapping, the bad smell at the beginning as the wrap gets cooked, and the fact that the wrap can actually shorten the life of the downpipes by trapping water and salt in contact with downpipes. I can cope with the fibers during fitting and the smell (as long as it goes way after a while), and I would mitigate the water/salt problem by spraying it with high heat silicon spray coating after wrapping.

Any other downsides or reasons not to do this that I’ve missed? Will it have the desired effect of reducing engine bay temps by a noticeable amount? Any other pros I might not have thought about? I don’t want to go to the effort of wrapping and spraying the downpipes if I get no appreciable benefit (not bothered about the aesthetics).

I plan to use this wrap: https://www.amazon.com/dp/B002R4U7G4..._CogaDbH1FAT4F

And this silicon spray coating: https://www.amazon.com/dp/B000MY3ML8..._CqgaDb0KV9P2R

Straight from product description "Design Engineering Hi-Temp Silicone Coating spray is NOT recommended for DEI Titanium wrap"

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[daytona rs7]

id suggest a ceramic coating instead. its a much cleaner look with none of the problems of heat wrap.

all your cons for heat wrap are true. I've used it on previous cars. the itch when installing. the smell after driving (does go away though). and the corrosion is true, although i didn't experience it since i didn't have the car for long.

[kebabman]

Do you know how much it would cost roughly to have a pair of DPs ceramic coated? Don’t really know where I would get it done but I’ll do some research, thanks for the suggestion.

Straight from product description "Design Engineering Hi-Temp Silicone Coating spray is NOT recommended for DEI Titanium wrap"

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Where do you see that? I don’t see it on Amazon, I see this:

“For use with all DEI exhaust wraps, HT Silicone Coating penetrates, seals and protects as well as helping to extend the lifespan of all DEI exhaust wraps. See special instructions below for best adhesion on Titanium exhaust wrap products.

Titanium Application Instructions
While not required for Titanium exhaust wrap, HT Silicone Coating will protect and prolong the life of the wrap. DEI recommends a minimum of three coats, each heat cycled for curing before applying the next coat. To cure, HT Silicone Coating needs to reach a temperature of 400°F for approximately 2 hours. Allow to cool before applying the next coat.”

Thanks for the heads up though, looks like I might not need the spray coating with a titanium wrap, and if I do apply it I need to heat cycle between coats....not gotta happen once it’s on the car but I guess I could try and fit my DPs in the oven or something. I know my wife would love that.

[mintytoo]

In the description for the wrap, from Amazon,

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[Dasquade]

id suggest a ceramic coating instead. its a much cleaner look with none of the problems of heat wrap.

all your cons for heat wrap are true. I've used it on previous cars. the itch when installing. the smell after driving (does go away though). and the corrosion is true, although i didn't experience it since i didn't have the car for long.

Not sure if ceramic coating is simular to thermo ZO coating (i think it is simular?)...anyway, my russian catless pipes were treaded with that but kinda sceptic about how effective that coat is. Afaik i does help (don't have my temp records at hand) for a bit but nothing helps better then some good old insulation and heat shield afaik. Like said i used the thick version and after a run i can almost put my hands on the turbo's/dp's while seeing though gap the turbo's are smoking red. Oh yes, that is bit the downside, while it is all good and nice to keep heat trapped inside the tubes, things inside get hotter and longer...
and i suppose that is why i frequently need to replace my coolant o rings (yeah i use cheap one compaired to the overpriced OEM ones but last as long...things just get hotter down there, luckly only inside and not outside).
heatshielded1.jpg
*ignore the heat wrap around the intakes, has been removed ;).

[daytona rs7]

these are the coating i was referring to.
https://www.jet-hot.com
good reviews for looks and ok for heat. but still better than no coating.


there is also this one, which has better reviews for heat reduction
http://swaintech.com/race-coatings/a...s-price-sheet/

[DubJunkE]

these are the coating i was referring to.
https://www.jet-hot.com
good reviews for looks and ok for heat. but still better than no coating.


there is also this one, which has better reviews for heat reduction
http://swaintech.com/race-coatings/a...s-price-sheet/

Another ceramic option I used is Cerakote. I don't have any data on how it affects temps I just put my DPs on. But it looks really clean.
20190423_123721.jpeg

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[The Infiltrator]

I found this on Amazon and might put it on my Mike's Dowpipes.

Heatshield Products 110614 Inferno Shield 6" x 14" Aluminum Heat Shield https://www.amazon.com/dp/B002UPL61U..._wXsaDbK4R8E5Z

[Dasquade]

I found this on Amazon and might put it on my Mike's Dowpipes.

Heatshield Products 110614 Inferno Shield 6" x 14" Aluminum Heat Shield https://www.amazon.com/dp/B002UPL61U..._wXsaDbK4R8E5Z

It appears to be just alu (flexible) shield without insulation...not sure if that will help much. I think that product is more designed to reflect heat instead of keeping heat inside....you better of with what i used also from Heatshield but the armor shield that comes with insulation (uhu more expensive but on ebay often deals...buy 3 pay for 2 etc).

[The Infiltrator]

It appears to be just alu (flexible) shield without insulation...not sure if that will help much. I think that product is more designed to reflect heat instead of keeping heat inside....you better of with what i used also from Heatshield but the armor shield that comes with insulation (uhu more expensive but on ebay often deals...buy 3 pay for 2 etc).

Click the link and look at it again. It's insulated and is meant to wrap. Even has a video, crappy video but still shows it.

[MolonLabe300]

If I ever decide to swap my Milltek DP's I'm going to get Mike's and will have them Jet Hot coated. They coat the inside and out and it will not tarnish or change color.

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[Chiromikey]

If I ever decide to swap my Milltek DP's I'm going to get Mike's and will have them Jet Hot coated. They coat the inside and out and it will not tarnish or change color.

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I’ve had a few sets exhaust components Jet Hot coated over the years and unless they’ve improved something or you choose flat black, it definitely looses its color and the finish turns dull.

I’ve also seen first hand how exhaust components can fail with wraps. Many people think it’s because salt/water gets trapped by the wrap and causes the metal to corrode but it’s actually a process called hydrogen embrittlement. The metal is forced to retain more heat than it can handle and it disintegrates as if it had been rusting for decades. The parts just crumbled away as the wrap was removed. It doesn’t usually happen with good stainless steel but I’d be careful around any lesser metals.

[MolonLabe300]

I’ve had a few sets exhaust components Jet Hot coated over the years and unless they’ve improved something or you choose flat black, it definitely looses its color and the finish turns dull.

I’ve also seen first hand how exhaust components can fail with wraps. Many people think it’s because salt/water gets trapped by the wrap and causes the metal to corrode but it’s actually a process called hydrogen embrittlement. The metal is forced to retain more heat than it can handle and it disintegrates as if it had been rusting for decades. The parts just crumbled away as the wrap was removed. It doesn’t usually happen with good stainless steel but I’d be careful around any lesser metals.

They now have 3 tiers of coating options. Back in the 90's I had some headers coated for my Mustang build. I never noticed a color change but, it was not a turbo car so maybe the coating wasn't pushed to it's operating limits.

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[kebabman]

Sent my downpipes off to Jet-Hot for the 2500F high temp version of their coating, should have them back end of the month, will let you guys know what I think once they’re on the car. May wrap them as well...not sure yet.

[kebabman]

Oooh, purdy 🤤

[The Infiltrator]

So glad this popped up again. I ended up wrapping the top parts of the pipe right off of the turbos. The CAT's didn't have any melting around it or the piping after the CAT's. But for the short time I didn't have them wrapped you can see that the piping off of the turbos melted the heat shielding. Holy hell!!

I had to take some of the bay apart again to wrap the top portions for now and seems to be good. I'll wrap the bottom half soon here but damn. Wrap your pipes people, it's hot in that bay! And no, nothing was touching and had plenty of space so I'm not sure how this happened and I haven't seen anyone else with this issue that didn't wrap them.

Wrap I bought:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[kebabman]

Thanks for the pics Infiltrator, I’m gonna wrap the top section of my downpipes over the ceramic coating with the same stuff you used, anything to keep heat out of the engine bay!

[Audibot]

Thanks for the pics Infiltrator, I’m gonna wrap the top section of my downpipes over the ceramic coating with the same stuff you used, anything to keep heat out of the engine bay!

If you have not thought about it, you should also look into getting the exhaust side of the turbo (turbine housing & flanges) coated as well.

[kebabman]

If you have not thought about it, you should also look into getting the exhaust side of the turbo (turbine housing & flanges) coated as well.

That would mean I couldn’t drive the car for a while, unless I bought spare housings and had them coated. Seems like too much hassle.

Belt and braces on the downpipes:

[Dasquade]

I kinda dought just coating the hot side of turbos would give you that much benefit over the hassle. Wrapping them with tape isn't realy an option....i went for wrapping thrm with isulated heat shield and helps a lot especially with the manifold done aswell...still things get hot down there. Maybe one day i explore a more heat extraction way to keep the bay cooler.

[wwhan]

I kinda dought just coating the hot side of turbos would give you that much benefit over the hassle. Wrapping them with tape isn't realy an option....i went for wrapping thrm with isulated heat shield and helps a lot especially with the manifold done aswell...still things get hot down there. Maybe one day i explore a more heat extraction way to keep the bay cooler.

One could add hood heat extractors as was done on the Dodge Hellcat to reduce underhood heat, but it does not look very nice.

[MolonLabe300]

Be sure to run a tap through all the threads to clean out any of the coating out of the 02 bungs and anywhere else has threads. I learned the hard way that it will save time later if you do.

[Audibot]

Hassle is relative for everyone. I mean, if OP's (or anyone else's) turbos go because of oil starvation, sounds like a great time to do it. Or if a non-RS7 owner decides to throw RS7 (or other) turbos on.

[kebabman]

Be sure to run a tap through all the threads to clean out any of the coating out of the 02 bungs and anywhere else has threads. I learned the hard way that it will save time later if you do.

Thanks for the tip, we did that and they went on pretty easy. Holy crap they make quite a bit of difference to how the car sounds.