What these guys are trying to tell you is - there's no such thing as an air-cooled turbo...

.. and if there was, it wouldn't be around long.

edit since I'm bored: Turbo's are generally all water cooled, with a few being oil cooled. Water cooled works better. It uses the coolant from your engine (antifreeze = your engine coolant) to cool the turbo down. Oil, obviously, uses the oil that's already being pumped through your turbo to cool it down. This doesn't work nearly as well.. and I don't think I've ever even seen an oil-cooled turbo in person.

What you're referring to is the intercooler. Do a search for 'air to air' and 'water to air' intercoolers, and a few threads should pop up. I'm a water-to-air guy, 99.4% of this board is air-to-air.

Look this shit up on google. Everything I ever learned about cars, I learned from browsing random-assed shit online, and from a book called 'Maximum Boost' by Corky Bell.