I keep hearing that blankets, wraps and ceramic coatings overheat turbos. Retaining heat in exhaust manifolds help with scavenging and lower under hood temperatures. Are our forum "self proclaimed engineers" just scaring me way from having a super awesome cool engine bay and efficient turbo setup? And what about using blankets and ceramic coatings together?

-Miguel Perez-Montoya

S13 turbo blanket
Walker Wilkinson's S13 says nighty night with heat blankets and thermal wrap. It's a necessary insurance but cosmetically could use some retouching. You still need to keep oil leaks from saturating a turbo blanket or it flares up as easy as a cigarette in a high school locker room. 

I love super awesome cool engine bays too so wrap it up! Obvious enough is anything fra-gil-e’ that is closely located to the turbo, exhaust manifold, and downpipe - all which will be emitting oodles of heat - should be wrapped with heat protective tape or a shield to keep them from burning up or sending your project up in flames. My personal experience was a fan wire that got a little too close to my snail and self destructed, almost taking my $$$ JDM engine with it. TG for water temp gauges!

Turbos generate a lot of heat and heat is a notorious power robber which makes reducing the temperature on the intake side better for power - colder air will provide a denser intake charge which is better for combustion. It will also help to keep wear and tear down on rubber and plastic components in the engine bay. 

A coated exhaust header will radiate up to half as much heat into the engine bay as one left uncoated. Coatings like Swain Tech and pipe wraps and heat control products from DEI or Thermotec can handle this. Swain Tech’s White Lightning ceramic (ceramic is known for being wear resistant and heat insulating) coating is about 0.015” thick, 5-8 times as thick as typical cosmetic coatings. DEI offers header wraps (in 3 colors - tan, titanium, and black), heat barriers, and wire protection.  Thermotec offers heat shields, wire sleeves, thermo flex protection for over hoses and wires, turbo covers, insulating wraps and manifold blankets, Hi Heat coating spray, and a thermo shield that uses an adhesive backed woven silica heat shield with aluminum finish, the whole enchilada. These products come in a variety of sizes and colors and are capable of many different temperature ratings from 500 degrees Farenheit to 2000 degrees Farenheit.

Nobuhiro Tajima's Pike Peak Monster
When you've got the cash to throw one of these turbos on your engine, it only makes sense to use inconel heat shields to create a thermal barrier between radiant heat and other uber expensive engine components.

ADDED BONUS- As you also pointed out, keeping heat contained in the exhaust manifold and turbine housing will also keep the exhaust gas velocity high which for turbo cars, helps spool the turbo and cash in on that scavenging effect.  It can even be helpful in naturally aspirated engines, where a good velocity exhaust stream keeps the exhaust gas flow high and develops a vacuum behind the closed exhaust valve that helps with scavenging when the exhaust valve opens on the next cycle.

Project Supra heat shields
MIQ's Project Supra is wrapped up like a Christmas present. Swain Tech's White Lightning thermal coating was applied to the exhaust manifold and housing while the 6 runner exhaust manifold was also meticulously wrapped in Thermotec's header wrap and Hi Heat coating spray. The coating spray protects the wrap from abrasions, corrosion, and damaging liquid spills.
On the intake side, Thermotec's woven silica, aluminized heat barrier will withstand radiant heat from the engine block. Ready for business!

It's fine to use a ceramic coating with any of the wraps concurrently. Wraps can hold in moisture and deteriorate over time so if you use a wrap on an untreated (uncoated) component, be careful wrapping it as any moisture trapped could lead to corrosion just like moisture on any bare metal could. A ceramic coating can actually help prevent corrosion from occuring. Any flaking or corrosion can also be caused by not using the correct temperature rating for the range of heat you'll be experiencing or using a company that doesn't prep well before coating. Wrap is cheap though - you can inspect it periodically just to make sure you're not experiencing any issues.

Project G20 wrap
Project G20's downpipe is wrapped in DEI's exhaust wrap. 


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Bill Washburn
Bill Washburnlink
Thursday, September 12, 2013 6:12 AM
Great info Sarah. One thing to remember is that the more you insulate exhaust materials, the quicker the material will deteriorate/time out.
Thursday, September 12, 2013 8:22 AM
Coating/wrapping headers on LS engines in the Corvette world is somewhat of a point of contention. Tuners claim insulated headers seem to be less detonation resistant and thus produce less power, or so goes the theory based on the coated and non engines they've tuned. LS engines are pretty big in the Formula D world, so someone should have something to add to this.
Thursday, September 12, 2013 8:42 AM
I have a hard time understanding why wrapping the exhaust of a N/A engine would have any effect on detonation. At the most basic level detonation is turbulence in the combustion chamber during the combustion phase and the exhaust port is completely closed. How could any modification to the exhaust manifold have an effect on this?
Thursday, September 12, 2013 8:56 AM
This is the tuners talking, they can only guess as to why an engine with coated headers tolerates less advance than an engine with uncoated headers (according to the engines they've tuned). I'm hoping someone here has heard of a similar phenomenon or can debunk it somehow. I have no personal experience with this, but I'd really rather put coated headers on my car without sacrificing power.
Thursday, September 12, 2013 9:12 AM
Hmm.... Taking a shot in the dark on the LS myth of less power with coated headers. Coatings and wraps keep more heat in the exhaust flow. So why would an engine get more detonation? One thing I can think of is if there's excessive back pressure causing some reversion flow of the hotter exhaust gas (due to the coated/wrapped headers) back into the cylinder. I could see that making the engine more likely to get detonation. Another thing I can think of is the exhaust header itself will be hotter. Therefore, maybe the engine head will be hotter. If the LS head has relatively poor coolant flow, maybe the hotter head could lead to more detonation.
Thursday, September 12, 2013 9:31 AM
Giving it a little more thought it could have something to do with EGR or o2 readings from the EM. There is a lot of assumption here but while a wrap keeps temps from seeping into the engine bay, you could assume that they keep temprature trapped inside the part they are wrapped around. In this case the temps would be higher in the EM causing the ECU to think that exhaust temps need to come down. That in turn affects the AF ratio causing detonation.

Re-reading that it still seems unlikely. First becuase the LS ECU should know how to properly mix AF and spark to prevent detonation since there are no other outside factors (like bad pistons/valves) and if it made its own adjustments it shouldn't cause that.

Second, assuming we are talking aftermarket headers (why would you wrap the stock ones?), like every other modern car, after installing I/E/H you should re-flash your ECU. This should circumvent the issue entirely.
Thursday, September 12, 2013 1:04 PM
Always good seeing someone else trying to set the record straight about rotaries. I do think you have a small typo with big implications though :).

"Rotary engines aren’t reliable, they’re finicky."

Shouldn't it be "aren't unreliable"?
Sarah Forst
Sarah Forstlink
Thursday, September 12, 2013 1:45 PM
@M-P: Or do I? ;). LMAO, owned by my fear of double negatives.
Thursday, September 12, 2013 3:07 PM
I'm curious as to whether there would be substantial benefits to WPC treating rotors, apex seals (if steel/aluminum), and housings. There's definitely the advantage of less friction, which may lower running temps a little, perhaps, lower seal associated damage/wear, etc., but to what extent?

Has anyone tried it?
Dan DeRosia
Dan DeRosialink
Thursday, September 12, 2013 3:35 PM
Mazdatrix offers it. I'd presume there's benefits.
Friday, September 13, 2013 12:44 PM
One thing I think you missed on insulating turbos, is there is a possibility of overheating the turbine housing (compared to the original design temp) and having cracks form prematurely. Most turbine housings will eventually crack under hard use anyway, so it is still usually a good tradeoff to use the insulation.
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