Well I couldnt afford a GTR, so I ended up with a GTS-4 sedan. As you know that means I have an RB20 with the intake that wraps around with the throttle facing the turbo side of the engine. All of the intercooler kits use some generic front-mount (inlet and outlet on opposite sides)with convoluted piping snaking through the engine bay to meet up with the throttle. Most cheap intercoolers with the inlet and outlet on the same side arnt vertical flow, they essentially have a small and long core thats folded on itself. Obviously this gives way more pressure drop than is necessary.
So instead of buying a good vertical flow intercooler for like $400, I bought the stock intercooler from my friends mk3 Supra for $50.
I paid more for the piping and couplers. Its only 2" inlet and outlet but I stepped it up to 2.5" piping, and the core is normally the issue with restriction anyway. I dont have any real data on intake air flow, or heat exchange efficiency for it, but some of the supra people make 400hp with it, so it should be good for an rb20. Fun fact the skyline intercooler is actually heavier, and looking inside the fins look super dense so Im sure its way more efficient. Doesnt really matter though since total cooling airflow is king.
See pics for install process. Looks like I have some sort of base model front bumper, a type M or a gtr bumper would probably require less cutting. My bracket is a little quick and dirty but I dont have a welder. On the supra the intercooler outlets face the right side of the car, so the mounting brackets are oriented funny for this application.
Oh side note: i bought 2.5" (63.5 mm) piping. Stock is 60 mm (2.36"). One of the stock couplers fit fine, another I had to set in the sun for a while and put the aluminum pipe in the freezer so I could get it to fit.
If you have questions feel free to ask.