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So my turbo kit is finally starting to arrive WOOT. Borg Warner 8374 from Turbosource.
Bare minimum I will get the downpipe ceramic coated. That has been well worth doing on my twin turbo downpipe(s) over the years.
I know AGES back that some ceramic coating on turbine housings or exhaust manifolds couldn't hack rotary heat and would just flake off/fail in short order. Has anyone had good experiences? And is it worth it?
Dale, another option is this downpipe blanket from a WRX
Been on my downpipe for 5 or so years.
Works great keeping the heat in and not radiating out to the engine bay.
Dale,
IMHO you have to make sure you use a shop that does coatings for racing teams such as NASCAR teams etc.. The shop that did my stuff for my twins several years ago knew how to use the right coatings for the heat produced and where to coat and where not to coat such as inside the housing. Depending on the amount of heat in the area, the selection of the coating changes. Here are some pictures of before and after. I had every single pipe and component coated in either in a blocking coating vs. a heat releasing coating depending where in the engine bay it was needed. My intercooler was also coated as many race teams do. No flaking of any kind anywhere I ever found. Under hood temperatures dropped significantly, and my intake temps also dropped.
Mike
Inconel shield is great for thermal management. I have not found the ceramic coating to be effective in thermal management in our cars.
ATP wrap in California is the manufacturer so i would go to the source instead of any middle man. You would need to send them your parts and they form them for perfect fitment
I used Swaintech White Lighting on my iwg manifold and downpipe. Wrapped the downpipe as well. On the manifold it's discolored and has some drips, but that's "normal wear" for the swain tech coating according to many sources. Definitely cooler in the engine bay. It's a thick coating too, not some thin ceramic paint. If heat shields are in the budget, that's the best.
ATP wrap is the way to go. 100% removable, last forever and actually works. Going directly to the source is much more affordable then you think! Chances are anyone that is offering inconel wrapping is actually sending everything to ATP and charging close to double.
Hey Dale, glad to hear you are coming along. Interested to see your interpretation of a "modern" single conversion.
As some other members have stated, you may not get the heat insulation properties you're after by virtue of the coating being in direct contact with the hot surface. If you could find something like corrugated stainless steel sheeting, you could fashion something similar to some of the setups posted here for less monies with comparable results. Inconel is not necessary for such an application (as we wish to reject radiant heat and insulate with an air gap) and the main benefit with such a material is that it does not lose as near as much strength as other non-austenitic (not containing nickel) alloys at elevated temperatures.
At the moment I do not believe there are any commercially available coatings that are suitable for the exhaust gas temperatures we see on these engines with respect to longevity.
Hey Dale, glad to hear you are coming along. Interested to see your interpretation of a "modern" single conversion.
As some other members have stated, you may not get the heat insulation properties you're after by virtue of the coating being in direct contact with the hot surface. If you could find something like corrugated stainless steel sheeting, you could fashion something similar to some of the setups posted here for less monies with comparable results. Inconel is not necessary for such an application (as we wish to reject radiant heat and insulate with an air gap) and the main benefit with such a material is that it does not lose as near as much strength as other non-austenitic (not containing nickel) alloys at elevated temperatures.
At the moment I do not believe there are any commercially available coatings that are suitable for the exhaust gas temperatures we see on these engines with respect to longevity.
As I remember, the coatings on my exhaust manifolds and turbos were rated above 2,100 degrees F. There are coatings out there that can withstand very high temps. I have many friends who are rocket engineers and have used some of these extreme coatings on their rocket parts for both military and NASA applications. Again, my exhaust manifold and turbo coatings are still pristine. You cannot use the typical aftermarket commercialized thick coatings. Find a true race shop that does it for the high-end large racing teams, like I did. I am sure the blankets do an excellent job, but that is for one component only. IMHO, you need to do everything to really make a significant difference, otherwise, using an analogy, it is a band aid on a large gaping wound. Helps but is it worth the trouble?
Mike
I recently refurbished an old knightsport downpipe. They are a decent stainless and last a long time (it's likely 20 years old) but can still corrode over time. I had it laser cleaned, added an O2 bung down near the trans section for better sensor longevity, sent it to Jethot for the highest temp coating option (2500) to prevent any chance of future corrosion. Then I sent it header shield for the wrap (I think either the same or similar to ATP. Got a quote for another after and ATP is definitely cheaper, but looks like the same product so maybe Headershield is sourcing from them, but I don't know for sure. They did state that coating and then wrapping will add no benefit to heat suppression, i only did it for minimize corrosion.
For exhaust manifold, I wouldn't bother with a ceramic coating due to the higher heat and would use atp or headershield
As I remember, the coatings on my exhaust manifolds and turbos were rated above 2,100 degrees F. There are coatings out there that can withstand very high temps. I have many friends who are rocket engineers and have used some of these extreme coatings on their rocket parts for both military and NASA applications. Again, my exhaust manifold and turbo coatings are still pristine. You cannot use the typical aftermarket commercialized thick coatings. Find a true race shop that does it for the high-end large racing teams, like I did. I am sure the blankets do an excellent job, but that is for one component only. IMHO, you need to do everything to really make a significant difference, otherwise, using an analogy, it is a band aid on a large gaping wound. Helps but is it worth the trouble?
Mike
Mike,
Perhaps I was not clear enough, but the method of heat mitigation I proposed can and has been implemented on all components of the exhaust system if desired. Your evaluation of the condition of the coating on your exhaust parts doesn't really address the heat rejection properties that may be afforded by it. I will conduct further research on the coating(s) you refer to as I am interested in learning whether there is some method that will serve to decrease the conductive heat transfer between the gas and the piping and display desirable characteristics with respect to longevity on our engines in forced induction applications.
As you are likely aware, there are three ways that heat is transferred. (conduction, convection, radiation)
I do not believe that only addressing conduction (the interface between the coating and the piping) have much merit in a system that exhibits all of the following forms of heat transfer, hence my assertion that one would likely observe the greatest results (reduction of radiant heat from exhaust components) from the method I referred to in my previous post.
I don't really like turbine housing blankets because if you ever need to remove it, it will likely be very brittle and in the event of an oil feed leak it can wick oil into the fibers and turn the car into a very fast candle.
I do agree that incremental improvements in heat management will yield the greatest results.
Was about $500. Shipping kind of stinks with sending it both ways, after needing to buy the downpipe in the first place, so if you have a good discounted way to ship it makes a big difference.
I wish I knew where to buy the raw material, it's 2 layer metal with insulation between, and then like a sticky tar substance made for high heat to stick it to the downpipe. It's quite a bit different than a normal heat shield
Was about $500. Shipping kind of stinks with sending it both ways, after needing to buy the downpipe in the first place, so if you have a good discounted way to ship it makes a big difference.
I wish I knew where to buy the raw material, it's 2 layer metal with insulation between, and then like a sticky tar substance made for high heat to stick it to the downpipe. It's quite a bit different than a normal heat shield
I've been kind of trying to find it for years off and on. ,Now I'll probably just send stuff out to the company Header Heatshield. I used to get this in recall kits from Nissan back in the early 2000's for cats. It was great because it was just like you described, two layers that sandwiched some sort of high temp fiberglass material which was amazing at insulating and very easily malleable. I used this on a few cars and people thought it was a joke at first because it make your hotside look like a baked potato de to the foil look and was completely different than the usual massive turbo blankets. Then I had them touch the turbo after just shutting down the car and it blew everybody's mind how well it keeps heat inside the turbine housing. One of my favorite things about it was how thin it is. I wish I had more because on my wife's S14 I have a large turbo blanket that touches a few things around it including a couple brake lines because it is so big.
Perhaps I was not clear enough, but the method of heat mitigation I proposed can and has been implemented on all components of the exhaust system if desired. Your evaluation of the condition of the coating on your exhaust parts doesn't really address the heat rejection properties that may be afforded by it. I will conduct further research on the coating(s) you refer to as I am interested in learning whether there is some method that will serve to decrease the conductive heat transfer between the gas and the piping and display desirable characteristics with respect to longevity on our engines in forced induction applications.
As you are likely aware, there are three ways that heat is transferred. (conduction, convection, radiation)
I do not believe that only addressing conduction (the interface between the coating and the piping) have much merit in a system that exhibits all of the following forms of heat transfer, hence my assertion that one would likely observe the greatest results (reduction of radiant heat from exhaust components) from the method I referred to in my previous post.
I don't really like turbine housing blankets because if you ever need to remove it, it will likely be very brittle and in the event of an oil feed leak it can wick oil into the fibers and turn the car into a very fast candle.
I do agree that incremental improvements in heat management will yield the greatest results.
Simon,
I agree with everything you said and do understand all forms of heat transfer. The issue with our cars is many will look at one aspect of thermal management and ignore many of the other major issues that plague the stock setup. There was a thread several years ago on heat or thermal management that discussed the extensive modifications I employed in my car. The ceramic coatings were only a portion of the changes I used. Many of my coatings were internal, external, blocker on the bottom, dispersants on the top, etc. depending on the pipe or component where we tried to address convection, conduction, and radiation the best we could. I went through this in detail with the professional coater for the maximum benefit of each specific pipe or component, using his experience with race team engine bays.
I only have cooler, ambient, ram-air feeding into my air intake through an aftermarket Abflug bumper which feeds directly and solely into an Autoexe air intake, which is also internally heat coated. Zero under hood hot air enter my engine, which IMHO is the extremely important in heat management. In the winter, my initial air intake temp can be 100-125 degrees F less to start with before entering the turbos. I have a coated U-type SMIC, which is directly ducted to the front bumper. Both the SMIC and the Autoexe have variable speed, high cfm, temperature controlled ducted puller fans that draw only cool outside air in. The hood is vented. All of this significantly decreases my under-hood temps and again significantly decreases my intake air temps. It's the whole system working together that really makes the difference. I understand this isn't for everybody, but if you have the time and the money it really does work well. Anyone interested in more details and pictures, look back at the thermal or heat management thread from 2019, I believe.
Mike
These folks sell inconel sheet with ceramic insulation backing and without. An approx. 23" x 39" sheet is $40 to 50 plus shipping. The international shipping is high but still reasonable given the prices for inconel and limited size sheet that could find domestic. (4) sheets (2 with insulation backing and 2 without) was around $400 shipped. They used to have an ebay store, but I don't see it now. You have to contact them to only pay shipping once since the cart applies shipping to each sheet.
two primary factors make heat mitigation especially Important.
charge air out of either the OE turbos or a single turbo is often above 300F and can be 400+ when the OE turbos are overdriven or a single is pumping out 500.
rotary EGTs average 200 to 400 F more than a piston engine. (optimal piston EGT 1320F)
intake heat reduction
relocate air filter if it is anywhere near the downstream of intercooler exhaust flow
the addition of water meth to the charge air takes 40-60 F out of the charge air
exhaust heat reduction
you probably remember seeing a picture of a turbo manifold, hotside turbo housing and downpipe all orange. that's 1800 F.
consider these thermal conductivity numbers:
Aluminum 210
Stainless Steel 16.2
Inconel 11.4
Mica .71 !!!!!!!!!!!
Fiberglass .2 (but melts at 1300F, that's why we don't use fiberglass packing in rotary mufflers)
i firstly draw your attention to aluminum.
think LIM. think 1800 F turbine housing nearby. think lean front rotor. if we measured AFRs on both rotors separately many of us would do some setup re-thinking.
enter Mica. Mica is all over industrial floors where heat must be defeated. i use a 12 X 13 X .25 inch sheet in front of my runners. easily purchased from McMaster Carr for around 70$.
where's Waldo, where's the Mica?
the next item is the turbo blanket. not all of them are top shelf and you don't want to compromise. the blanket in the picture is the latest DEI item and it has been significantly improved as has their wrap product. both products, wrap and blanket incorporate materials similar to mica. beside decreasing heat radiation towards the LIM runners, a turbo blanket drops engine bay air temps significantly and that includes at your air filter. i measured 105 at my air filter and 125 under hood on an 80 degree day. underhood air temps without the blanket would have been around 140.
ceramic coating has been the subject here. after fairly extensive conversations with various ceramic coating companies i am of the opinion that there is nothing wrong with the coatings especially w re to reducing surface degradation but i doubt much is achieved as to heat reduction. after pretty much nailing one of the ceramic coatings company owners as to the amount of heat reduction (low) he said well if you really want to accomplish more reduction you should coat the insides of the pipe as well. yikes.
OTOH, premium wraps from DEI (Titanium Wrap) or PTP (Lava Wrap) are quite effective.
finally doubling back to the material properties list i note there isn't much difference between inconel and stainless steel...
Just a fyi. Inconel shielding is just a term that is used. It's not just a Inconel cover. Inconel is just the visible outer shell which protects the actual material inside the shielding....
03-08-24, 03:39 PM
