Hey,

Here's one charge cooling trick that can be used in eg. turbo wastegate
on intake side:

http://en.wikipedia.org/wiki/Vortex_tube
http://www.exair.com/en-US/Primary%20Navigation/Products/Cold%20Gun%20Aircoolant%20Systems/Pages/Cold%20Gun%20Aircoolant%20Systems.aspx

Pressurized air comes in from side, forms a vortex inside, and separates
hot/cold air to opposite ends. Wastegate will be on hot side.
This might work fine if there is excessive boost available.

Downside is a bit of pressure loss expected, and not helpful near
critical altitude. But could boost take-off power just fine.

Perhaps this can also be used to cool the exhaust gas before turbo...
Properly dimensioned vortex muffler where there is a wastegate on the
other end, and turbo duct on the other..
But it could be that the hot side becomes atrociously hot, and anything
melts - at least without active air cooling...

Cheers,
Petri

Sounds like a great idea. My band saw as a compressed air cooling
nozzle.

Paul Lamar