Koyo Radiator questions.

[Max777]

hey guys, I just found a killer deal on a koyo Rad, but it's an S4 R model.

The guy is selling it with an electric fan, realys, and a nice rad cooling panel, etc,so I think I will buy it even if it doesnt work right on the S5, but here's my question:

On S5 cars like mine, we dont have the coolant cap on the water neck by the engine, and the rad cap is raised a bit to it's level to the water neck.

If I throw the S4 koyo on my car, I suspect I will have a headache trying to get all the air out, right?

[WE3RX7]

I dont think you'll have a headache per se, just more time to burp the system.

You could also install an air separator tank which will make life way easier in general. If you do any track events or regular flushes of the coolant system, you should have a good metal AST.

[Max777]

AST? I am going to search, I know, but would you like to elaborate on that a little for me? I know what they kind of look like, but I have no clue as to how one should be setup on an FC.... seen them on 240's however.

This one seems like it's made for the FD...

http://cgi.ebay.com.au/RX-7-FC3S-FD3...105124001r6914

[Fidelity101]

that 2nd picture there is stupid, doesn't even show the product, its the IC and IC piping its showing off...

[Max777]

So I take it that since, again, the S5 does not have the thermostat housing cap/bleed off, the blue thing will have a hose going to the AST, and then another hose going from the from the radiator overflow will be going to the AST, and from the ast, there will be a hose going into the overflow tank...

but that leaves the last nipple on the bottom open... from what I read, that is supposed to tap into the bottom of the radiator?

[Max777]

So, does anyone have an FC with an AST setup they could possibly share with us?

[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.

[Max777]

Thank you for the reply. I think that I would like to get an intermediate fill pipe. This seems like the easiest solution to my problems as I have recently bought a brand new S5 thermostat neck...