Quote:
Originally Posted by nelsmar
I think you are confused on what these different components are. The pipe that was "wrapped" was wrapped in a reflective tape to help reduce radiant heat. This pipe is a charge pipe. It has pressurized air that has been cooled via the intercooler. The turbo charger compresses air which increase the temperature and the intercoolers role is to attempt to get it as close as possible to ambient once again.
Your engine bay is a box with hot components in it. If you are not moving all that is moving the air through the bay is the fans. Which are blowing hot air from the front cooling elements into the bay. This results in a bay ambient temperature that is a fair bit higher than the ambient atmospheric temperature. This may be 10-50F above ambient.
As you are accelerating the velocity and volume of the air increases and the air through the MAF charge pipe (seen above) cools down due to the colder air passing through it. Due to the velocity of the air there is less heat transferred. conduction (not to be confused with radiant).
So looking at the bits above if you are sitting idle for a few moments and that ambient bay temperature starts to rise the charge pipe absorbs heat via methods of conduction and radiation (this pipe is typically black, and black has a very high radiant absorption capability). Due to the low velocity of the air going through this pipe it ends up soaking up the heat resulting in a high intake temperature. At low throttle bits and idle the car starts sucking up hot air. Hot air and hot fuel mixed together combust easier. Due tot his you have to pull timing from the ECU when the intake temperature is over a certain value. On the OEM ECU Map this starts happening at 50c. Here in Phoenix at idle I range 45-60C. So coming off the line and at very low throttle bits when I'm not moving much my car bogs due to the excessive heat. Adding a reflective wrap around the pipe can help reduce the effect by removing the radiant heat exposure and only allowing the conductive heat exposure.
You mentioned the intake pipe. The intake is attached to the turbo and is just a few inches long (if that). Insulating this does very little especially considering this air is going to go through the intercooler.
So yes even if you wrap / coat your hot components you still have a mass amount of heat being thrown into the bay by everything else that makes the car & ac work.
Wrapping the charge pipes is not at all required, and the car will run just fine without it. The difference when really getting aggressive with the car is minimal on that one piece but when people are trying to perfect everything every little bit adds up.
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The emissivity of the black body alone would have a larger cooling effect at idle than any other color, though with the added thickness of insulation, wrap might provide better cooling due to lower emissivity.
I'll pass on the wrap for now since I'm not chasing diminishing returns, but I'd do it for the aesthetic factor moreso than cooling in any case.