Contour Enthusiasts Group Archives Forums Modifications Duratec Performance Intake heatshield results

I recently made a heatshield for my K&N cone airfilter, to attempt to get cooler air into the intake. I have yet to improve the intake ducting through the wing but today I took some readings of the difference the heatshield made. Although the heatshield did reduce the maximium temperature attained, it also slowed the cooling of the intake air as the speed increased, which I found surprising. Generally, I was 3oF cooler without the heatshield over the same route. Disappointed in the intial results, I will improve the ducting through the inner wing and re-test but at the moment, the shield stays off.

For those interested, here's a pic with the shield in situ:-

and a plot of the results:-

Here's a few observations and some input comparing your heatshield and mine, and the results you have achieved. Now, before anyone flames me, I don't have a graph plotting out my results,nor am I putting down Paul's heatshield design, I'm just trying to provide some insight to his results and illustrate some design differences.

First of all, pics of my heatshield...
[img]http://www.fototime.com/ftweb/bin/ft.dll/standard?pictid={224AF14B-95D6-4972-AC44-A89FE06A8A89}[/img]
[img]http://www.fototime.com/ftweb/bin/ft.dll/standard?pictid={2E4AEBD8-6FF2-4E2D-86B9-47BBC52BCE4B}[/img]
Now, there are several major differences in our two designs that I would like to point out that would cause different results. First of all, your heat shield appears to be made of metal, with tends to absorb heat. Mine, is made of a heat resistant plastic, which transmits heat less. Secondly, I installed my heat shield so that my MAF would be shielded from engine heat as well, given that I had noticed on numerous occasions prior to its installation that the MAF would be as hot to the touch as the upper manifold. Not good, in my books. THirdly, and lastly, your heat shield is a closed design which wraps around the air filter, "restricting", if you will, pathways for the air to flow to the filter somewhat, which may account for the higher temperatures at speed. With mine, it is a straight across design, blocking engine heat from anything beyond the battery, in fact,it uses the battery as part of the shield as well. I used to have a bad pinging problem on hot summer days when I drove aggressively, but since I installed the heat shield two summers ago, it has disappeared. The filter and MAF are cool to the touch as well, after agressive driving. Not so before the shield.

I don't think the metal shield will heat the air that much although it may transmit heat better than the plastic. The restriction of airflow is the biggest problem. When the car is moving the air inside the compartment tends to be a lot cooler than at idle. The demands of the engine at WOT are higher than the factory fender inlet can provide.
warmonger

Do worry about rubbishing my design, only something I knocked up to test
Intersting test though, you are right my heatshield is made out of polished stainless steel, that's all I could find to work with.

Did not think about enclosing the MAF also,something for MKII perhaps . Also like Warmonger, I think the factory air inlet is not enough, hence the next thing to try is to get more in. What interested me was atfer driving, the airfilter is a lot cooler to touch and the heatshield is only barely warm. What appears to be happening is that at idle / low speed, the heatshield is reducing the air temp by a small amount but as the speed increases, the air rushing in the front of the car is sufficient to not be heated up greatly. With the heatshiled in place, this air cannot get at the fitler so effectively. Anyway, an intesting start, I will mod the air intake and repeat the tests, I do like your design Jeff

The metal will absorb & retain heat, then transfer it to the intake charge side of it much worse than plastic will though!

Also the thicker the design the less transfer from one side to another. You used very thin metal plate.

Do you have a product over there like "plasti-dip" ? A 1/8" - 1/4" coating should help quell some the transfer problems since the metal is so thin. (it won't retain a lot of heat being thin - A plus!)

Did you enclose the bottom portion as well?
Heat rise from below is a big factor in heat soak (electric fans, radiator wash, transmission)

As Demon said, look out from below. The hottest air is blown up from the radiator by the fan toward the filter - if the bottom is open hot air may be trapped inside. If you put a hole in your shield facing forward, cooler air moving over the battery can be used, along with your fenderwell duct.

Back to the drawing board I feel...

Thanks guys for your help; it was interesting matching the design theory with some quantifiable results

Paul.