the ebay intercoolers with no name cores work, but the garrett cores work better.
just talking about the cores. like don said, a good core will have turbulators (sp). the short of it they give the ic more surface area for the now turbulent air to come in contact with.
i really don’t want to type a lot before i drink coffee.
oh, and didn’t i do a write up on intercoolers, and efficiency around the same time i did one on bovs? i will have to dig that up and post it if i haven’t already.
anyways, if the seller cant tell you how efficient the ic is, i wouldn’t consider buying it for a high hp build.