I'm not aware of an off-the-shelf solution to your problem, you're probably going to have to fabricate something on your own.
ESS uses an air-water intercooler on the twin screw systems but it utilizes Laminova cores housed in a custom cast aluminum intake manifold, which also supports the compressor. It has water lines which run to/from another heat exchanger behind the front bumper. The coolant is circulated by an electric pump. The TS manifold won't work with your VT-1 kit though so the trouble lies in how to effectively package some sort of heat exchanger in the intake path between the compressor outlet and the intake ports in the head.
The only company I'm aware of to attempt an air-water setup on a centrifugal system is VF-Engineering. They did it by creating a custom intake manifold but they only have one for the M3 and, IIRC, they wouldn't sell a manifold by itself anyway because they would prefer to sell an entire kit.
As I said, I don't believe there's an off-the-shelf solution for you and the only way I'm aware of to make it work is to custom fab an intake manifold with an integrated heat exchanger. It's not a trivial task to design an intake with proper flow characteristics. Even if you were to accomplish this, you would still be giving up the stock dual resonance intake design which would likely cost you some low end torque which your centrifugal compressor isn't going to make up for.
Long story short, just stick with the 7 psi pulley ESS originally spec'd for the system.
Last edited by TxZHP04; 08-31-2008 at 09:25 AM.