Originally Posted by crystalhelix
Responses in red, feedback appreciated.
I'm not too familiar about the thermal dispersant you speak of, so I wouldn't be able to offer an opinion.
As far as JDM TMIC vs. Perrin or TXS or APC or whatever brand TMIC, In that location, on an STi, they're ALL a PITA to get in and out. My next question would be a cost/benefit analysis of JDM TMIC vs. brand X TMIC. Which one flows the best, has the greatest cooling efficiency, the lowest pressure drop, etc for your money. Of which I'm sure there are plenty of opinions here on Nabisco.
If you're shooting for 350awhp on C16, I'm assuming your class allows boost modification and engine management. That being said you should be able to get close to those numbers, but the VF39 really starts to run out of breath at those levels. If you are allowed I would probably recommend an upgrade like the 20g. Same boost response as stock, MUCH better top end. Also you wouldn't lose anything on the bottom end either. (Slightly unrelated to your question, but worth considering)
Also, are you allowed to run an IC sprayer? I would think that can become a significant helper as well. Water reeeeely helps fight heat soak and would extend the cool periods for your runs. You might even consider the 12L JDM bottle (mounts across the back seats).
But I agree with javid, et all. I probably would not spend my money on a 15% bigger core. For a little more (or less if you can find one used) you can get a lot more internal volume. From what I've read even the eBay TMIC cools pretty darn well.
Hope I gave you a few things to think about, or even pointed you in new directions.