In theory, reducing exhaust heat will improve the performance of my cold air intake.

I found some decently cheap header wrap, and my headers have some ugly stains.

Is it worth investing my time and money or should I just leave them alone?

For a non-turbo car, like the 420a, I would say it's not really worth the effort. If you have a free afternoon or two, and feel like tackling it I don't see why not though. it should decrease under hood temps, but you may not see a massive change in performance, or even a minimal one if your intake is still in the engine bay or not ducted.

To me, the biggest benefit of exhaust header wrap is the fact that it keeps exhaust energy (heat) in the pipe to keep velocity high as it travels through it. Thinner piping and less insulation of the exhaust with thin wall tubing is going to cause rapid cooling and slow the exhaust gasses down.

Once again, probably not going to produce a noticeable difference all said and done.

There are also concerns with exhaust wrap in wet or overly humid environments that traps moisture against the pipes and causes them to deteriorate. I'd suggest ceramic coating if you do anything.

llxkevinxll said:

There are also concerns with exhaust wrap in wet or overly humid environments that traps moisture against the pipes and causes them to deteriorate. I'd suggest ceramic coating if you do anything.

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This is a long term concern, though if you do the wrapping process correctly and use the silicone sealer spray, it should be a very long time before that happens. Plus you'd have to be in a very wet place constantly I feel like. I've wrapped headers up here, both with and without paint and silicone sealer, and never had anything more than light surface oxidation on the bare stuff.

I do think ceramic coating is a great option, and you can wrap the good coatings for even more heat retention.

This is a good read, dont do it unless you want to be buying new headers at some point, and for those buying expensive manifolds, it is sure to void warranties
https://www.centuryperformance.com/exhaust-header-heat-wraps-do-not-use.html

My local Autozone has some 1500 degree resistant paint that I can use instead. But I feel that would be too thin for me to even notice a difference. I suppose I'll leave them alone for now.

That paint is only for color, not heat control.

I've ran heat wrap on my manifold and downpipe for 10+ years. Just recently removed it to alter the downpipe and manifold, no damage what so ever to the metal. Downpipe is stainless 304, manifold is steel sch 40. This car gets under 5k miles per year, and is rarely driven in rain so maybe that makes a difference.

I have been considering wraping my o2 and downpipe. I have a blanket over my fp mani and the hot side of my green is ceramic coated.

But my o2 and downpipe have no heat shields and when I open my hood after a long drive the heat just pours out of those areas, not to mention they are right by my intercooler pipes and alternator.

Im thinking the benefit of wraping the o2 and downpipe out weights the negative. Im not Nessaserlly looking for any HP gains, just reducing heat to all the other parts of the engine.

The down pipe is much cooler then anything pre turbo, so you would most likely have less of a probability or a cracking issue in a colder spot, prob be fine to keep alternators alive.

Th3ory, I agree that reducing heat to other components would be great. But, I think finding a way to evacuate the hot air in the engine bay will be more helpful than insulating the pipes.

I am working up a prototype under hood vent system that will rapidly evacuate a volume of air equal to several times the volume of the engine bay each minute, when the under hood temp starts to climb. Hopefully entirely passive, so I won't have to worry about heat soaking every component under the hood when I am waiting on a light or bumper-to-bumper traffic. It should make the radiator fans far more effective as well. Just something to think about!

Good luck!

Archer Fabrications said:

This is a good read, dont do it unless you want to be buying new headers at some point, and for those buying expensive manifolds, it is sure to void warranties
https://www.centuryperformance.com/exhaust-header-heat-wraps-do-not-use.html

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That article talks about thin wall tubing that's either mild steel or cheap 400 series stainless. Neither of which is used on our cars. We use heavy wall 300 series pipe for oou manifold and 300 series tubing for exhaust component that has much better corrosion resistance

1990TSIAWDTALON said:

That paint is only for color, not heat control.

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Absolutely.

I'm gonna wrap the downpipe for testing purposes. It's the exact same material as my headers. If that goes well for a while then I have no problem doing the headers.

And I'm sure in 10 years my engine will need another tear down so I can get some custom fab headers by then.

Thanks guys

The engine bay looks pretty clean with wrapped headers. The most natable part though is the heat difference. Before when I opened the hood, I would get punched in the face with a wave of heat. Now, it just a warm wind...

Make sure to use the silicon spray to coat the wrap. If you don't it will tend to frey anytime you touch it or rub against it working on the car.