Auxiliary Radiator Sizing

[OGR34]

I was wondering if anyone knew how to properly size a radiator? I'm looking to install one or two small auxiliary radiators from an after market company and mount them as such on my Focus ST:

The kit you see in that picture is by Mishimoto. I would get this kit however there have been complaints that it still overheats at the track. Right now I'm running about 400 whp on my Focus ST and the stock radiator overheats quite quickly. My goal is to be able to size a radiator (or two) that will fit in the same compartment as shown above which can support extreme track conditions with power figures of 500 whp. I'm not very well versed in heat exchanger design, but I have basic very engineering knowledge from university. Can anyone shed some light on how I can start figuring out what core size I need and what factors I need to be aware of? Any help would be appreciated.

 

[OGR34]

Fixed image size, was way too big

 

[tbuelna]

Are all of those cores used for engine coolant? Or are they oil coolers and/or intake air charge coolers?

Rather than adding more cores just for engine coolant, it would be way more efficient to simply use a single larger core. Having a custom aluminum radiator made is not that expensive.