IC Heat Soak

I thought I would start this mainly out of curiosity and also because of the growing popularity with larger tmic's. Anyhoo, we all know that without the heatshield over the turbo your IC is seeing a tremendous amount of heatsoak. I'm starting this thread over here to sort of continue and throw in some other information from the thread I'm active in on IWSTI. I'm going to try to take a few temp reads (idle and hot) under a few trials of different ways to keep heat retained and soak down in the engine bay (esp. for the IC). I am hoping I can get a hold of the right tools for this. Optimally, I'd like to use a high temp infared pyrometer for any sort temp measurements.

So, here we go. Heat can be transferred between two objects in three ways: conduction, convection and radiation. Conduction is the transfer between two objects in direct contact. Convection is the process through which heat travels through a fluid our air. So our dilema is that our dp/turbo heat the air around it which in turn heat our IC. Heat is also cappable of travelling through infared radiation, similar to light. This is where a reflective metalic surface can be used to deflect the radiation away from the intercooler.

Alright, so with this in mind, we can figure that our heat shield does a decent job of blocking the radiation but it is still a conductor so it will pass heat. The benefit though is that air is a decent insulator so we're creating 2 barriers here. dp/turbo -> air -> heat shield -> air -> IC. This creates two metal-air barriers making conduction twice as difficult than before. Obviously the effect of this barrier deminishes as the parts get hotter; but, if you can keep the air flowing with relatively fresh air, you can keep the conduction to a minimum. Alternately, if you can keep the heat shield cool, you restore the temperature difference between the metal->air barrier helping reduce heat conduction. Keeping the heat shield cool can be done by making it bigger (so it can absorb more) or by allowing it to tranfer heat to some other, preferabley very conductive, object like the chassis for example.

So my question is, is it advantageous to get a stock shield (most likely modified) ceramic coated and then apply an additional layer of thermal shielding on the inside? In theory, it seems like it will work. I am going to test this out and see if it is really worth the money. I'm not sure how far I am going to take this, but I'd be curious to see just how far I want to go. Maybe I can work with SS or TS on this and get some dyno pulls in as well. I'd like to test the following I suppose:

With factory heat shield (cut to fit my dp):

• Idle/Cold temps inside and outside heat shield
• Hot temps inside and outside
• IC temps (Cold/Hot)
• 6 pulls to est. a base/avg

With ceramic coated heat shield (cut to fit my dp):

• Idle/Cold temps inside and outside heat shield
• Hot temps inside and outside
• IC temps (Cold/Hot)
• 6 pulls to est. a base/avg

With ceramic coated factory heat shield + additional layer of some material (tbd) on the inside of heat shield (cut to fit my dp):

• Idle/Cold temps inside and outside heat shield
• Hot temps inside and outside
• IC temps (Cold/Hot)
• 6 pulls to est. a base/avg

Thermal Wrap? As per Jason's request, I want to throw thermal wrapping in here as well. Although, I do prefer coating, I think its fair to test this method out as well. I'm not entirely sure as to how I am going to go about wrapping the heat shield, but I'll figure it out. He just offered to donate his old heat shield, so now I'll have two complete ones to test with. The only difference between the two will be that his will be uncut. This is a slight difference, but I do not think it will one cappable of creating large inaccuracies in my measurements. Regardless, I will attempt to do identical testing to a wrapped heat shield to have a solid comparison (I hope).

I just got off the phone with Siegel and learned a few things from him. On a normal day, under the hood temps see no bigger than 180-200°F. The surface of the turbo is easly at 400-600° and up to 800°+ when running hot. A simple turbo blanket will hold the heat in quite well, allowing the ambient air outside of the blanket to be around 130°. But we're not looking for a blanket, we're trying to see if messing with the heatshield some can prove beneficial. Siegel also thinks a noteworthy spot to measure in the bay is the endtank on the otherside of the IC, this is where he has seen the largest variance in temp (±40°).

Now, what would be ultra-pimp would to see if I could get actual temp probes (6 to 8 of them) and put them all over the engine bay. This would allow me to actually do road testing (with real air circluation conditions) as opposed to dyno testing (fans and the SS Leaf Blower IC Cover Technique©). Siegel has more than happily agreed to hop on the project and allow me to dyno the car there. I'm talking with TopSpeed right now to see if they're interested as well.

If anyone is interested in seeing this go through and would like to throw a few dollars my way to help make it happen, please PM me. I am hoping to work out the dyno pulls at a reasonable price with SS or TS. Not sure on the pricing of the ceramic coating, I cant image it will be all that expensive. Additionally, I'd like to coat my DP and see if there is a noticable difference, but we'll leave that one for another story.

More to come I suppose,

 

From my understand, a big blanket will go down and attach underneath the car so itwill be out of the way. I do believe that the heat shield would still remain mountable. Siegel said that withthe blanket, ambient temps are around 130F.

 

Yeah, I'm doing this mainly to confirm or deny claims about the HS and as a low price modification for those concerned with heat soak and such. Thanks, I may just have to take you up on the offer for the pyrometer.

Miller's is really reasonable with their pricing--45 to 75 to do a wheel is damn good. I will more than likely end up getting my DP coated there, as well as I will be using them for the duration of this experiment.