heat shielding the intake system

[notout86]

The air filter box and the air tube from it are black and I think they must absorb radiant heat from the engine, thus raising the temp of the air within and reducing its density.

Is it worth shielding with thick shiny Al foil on the engine side?

Has anyone a way to check the temp. before and after shielding, or better still has anyone with a dyno to test the theory / measure the power increase?

[Captain Snooze]

One can use Android app Torque to measure intake and ambient temperature. From my observations at standstill/idle inlet temperatures are higher than ambient. After about 10 minutes of driving intake temperatures have dropped significantly. This is just around town so any difference in power is meaningless. On track where wot is the norm in between braking the difference between ambient and intake is not significant.

Tl,dr. Don't worry about it.

[stevesnj]

Originally Posted by notout86

The air filter box and the air tube from it are black and I think they must absorb radiant heat from the engine, thus raising the temp of the air within and reducing its density.

Is it worth shielding with thick shiny Al foil on the engine side?

Has anyone a way to check the temp. before and after shielding, or better still has anyone with a dyno to test the theory / measure the power increase?

Yeh i saw a shield on top of the intake tube and that baffled me...lol I think one like a 1/2 circle shield under the tube where the heat can at least be directed around the tube. The rubber tube is thick enough it should not raise the temp too much. The color of the tube won't matter.

[raven1231]

Putting Aluminum foil around the intake can net some rather substantial gains. It has to be reynolds wrap however, for durability and better heat dissipation. Good luck!

[Kodename47]

Originally Posted by raven1231

Putting Aluminum foil around the intake can net some rather substantial gains. It has to be reynolds wrap however, for durability and better heat dissipation. Good luck!

Really?!

In town driving it may reduce heat soak but one you're on it the airflow speed is increased, there isn't going to be much thermal transfer between the plastic and the air passing through at velocity. There is some but the % of air volume affected is insignificant. IATs under WOT will almost always be the same as ambient. Once the heatsoaked air is used, it's replaced by fresh air.

Does heat wrapping help? Sure. Significantly? Not for power.

[Calum]

Originally Posted by raven1231

Putting Aluminum foil around the intake can net some rather substantial gains. It has to be reynolds wrap however, for durability and better heat dissipation. Good luck!

Here /s I think you dropped this.

[notout86]

That's what I thought Kodename47 i.e. mainly beneficial versus heat soak at idle and low speeds around town. It is a passive measure and once in place, the benefit, however small would add up over time and become significant.
A half circle shield around the tube is all that is needed and minimises the weight penalty

As for the color of the tube, black absorbs most radiant heat. In a car lot, put your hand on a black car and a white one and be amazed.

[notout86]

Originally Posted by Calum

Here /s I think you dropped this.

please explain

[Calum]

Originally Posted by notout86

please explain

Here /s I think you dropped this.

[Captain Snooze]

Originally Posted by notout86

black absorbs most radiant heat.

It also radiates heater better.

[ramiram1984]

Ugh close thread

[Ultramaroon]

Originally Posted by raven1231

Putting Aluminum foil around the intake can net some rather substantial gains. It has to be reynolds wrap however, for durability and better heat dissipation. Good luck!

This is a common misunderstanding. The high emissivity coupled with the reflective properties of the aluminum require it to be applied inside the cavity for greatest gains in this application.

[notout86]

Originally Posted by Ultramaroon

This is a common misunderstanding. The high emissivity coupled with the reflective properties of the aluminum require it to be applied inside the cavity for greatest gains in this application.

Could you elaborate please Ultramaroon. I take it you mean the rubber tube or plastic has the high emissivity? The foil is hardly contacting them and there is a narrow air gap between. Why is it better to have the foil inside. What sort of difference do you think it would it make inside or outside. It is hard to put the foil inside.

I once learned a lesson I have never forgotten. We had a wood stove that incorporated a system of copper tubes that heated water passing through the tubes then through a tank. It took a long time to heat the water so I tried Al foil over the stovetop. Whereas the water used to take a couple of hours to become hot enough for showers after the foil it would actually BOIL after only 45 minutes. The top of the stove (cast iron/steel) would glow red hot. With the foil cover you could get your hand as close as possible without actually touching and it was only warm. The foil was emitting VERY little heat. After a time there was a thin layer of black soot on the underside of the foil but I could still put a hand as close as possible without touching.

[notout86]

Originally Posted by notout86

please explain

Sorry. I still do not understand and neither does my wife. Please spell it out as if to a 7-year-old.