How we drop intake air temp 40+deg.

[jb92563]

Thats a good point Ian, its radiant heat therefore blowing air into the engine compartment would not have a huge effect, and so the foil is supposed to reflect the "radiation" and prevent the walls of the airbox from getting as hot.

What about those muffler heat tapes/blankets, those are also designed to prevent heat absorbtion and can further insulate the airbox.

I suppose a combination of all these things including more air blowing out the "conventive" heat as well in the engine compartment should all help.

[Ian c]

Exhaust wrap would work but weighs a lot more than gold foil

[sb01box]

I believe that wrapping the plastic does reduce the absorption of radiated heat and therefore the increase in the plastic body temperature will be less.
google plastic for auto and got DuPont zitel PA66 is one of such plastic.
can't find thermal conductivity nor thermal emission (absorption) coefficient.
as a norm, plastics do not have strong thermal conductivity and emission/absorption.
so i'm wondering how much of an influence does the manifold have.

[Topless]

I gotta go with Mike on this. I need to see some before and after hard data because it goes against what I understand about radiant heat transfer.

For comparison, 40 degrees is the equivalent heat rise across a highly efficient copper heat exchanger inside a 400,000 BTU gas fired water heater with 1,500 degree F. flames lapping at the copper coils. Water velocity is also spread out and slowed down to maximize contact time and heat rise. That is a very different environment than a Boxster intake.

My initial engineering thoughts:

- The plastic box and intake are poor conductors of heat.
- Intake air velocity is pretty high so not much heat-absorbing contact time.
- High velocity air is a relatively poor conductor of radiant heat.

Best guess: Little if any measurable intake radiant heat rise. This is easily tested with a temp probe at the intake grill for ambient and another just ahead of the throttle body. Compare results.

[The Radium King]

iirc there is an intake air temp sensor; ecu uses it to revise fuel trims. it's mounted on one of the intake plenums. you can log the data with your durametric. more likely the wires on the sensor heat and affect the sensor reading.

[Topless]

Originally Posted by The Radium King

iirc there is an intake air temp sensor; ecu uses it to revise fuel trims. it's mounted on one of the intake plenums. you can log the data with your durametric. more likely the wires on the sensor heat and affect the sensor reading.

It should be pretty easy to test the wrap then.