Well, after doing a bit of reading, trying to decide how to run the piping in my HR31 Coupe ....
I've found very little conclusive info.
I don't like the design of the generic kits with the radiator crossover - seems like too much pipe, too many connections, and I'm not keen on cutting new holes.
The ARC/AVO style kits with the 90 degree endtank on the drivers side end and stock-ish pipe layout in the engine bay seem good, but intercoolers like that only seem available in their off the shelf kits and the prices are ridiculous (the most extreme being ARC's HR31 GTS-R Gr. A spec kit at $3,500!).
Finally, the last option seems to be the 120 degree turn off the throttle body, down under the headlight and 600x300x? generic intercooler style, with larger piping off the turbo following the stock routing out of the engine bay. This would make access to a couple of things (oil cap, some hoses and sensors) a little difficult and necessitate re-routing some pollution gear and vac hoses, but seems to require a lot less piping, less connections, and removing one pipe to fill up with oil is no huge problem . As well as that it seems to be the preferred method when the RB20DET was being used in touring car racing.
Any thoughts on my logic?