Koyo Radiator questions.

[vex]

Cough, cough... Crickets... (check my sig) I know it's an old thread but it would be helpful to continue the discussion over there.

As for your question there's different routes you can go.

First and foremost you do not need an AST. You can run your car with just the Radiator and it's fill cap. You will have to burp the system which is a lot more work on your part, but it's do-able.

Second you can get a intermediate fill pipe, which you can put in between you thermostat housing and your radiator hose and fill from there. That should make your life much similar to the S4 guys.

Third you can put on an alternate thermostat housing. Little more work which may involve some fabrication, but all in all not a bad thing to consider.

Fourth you can do an AST. Basically it would need to be close to your radiator (mostly for convenience). Experiment to see what works best for you (both functionality wise and aesthetically).

Any questions regarding the radiator specifically I think I answered in the thread.