"thnks for posting, but those numbers are just general dimensions of the whole core. what im trying to figure out wont be able to be determined from these. the density of the internal turbulators and their area are going to affect the cfm and pressure drop. the style of intercooler should affect this as well. i know the greddy's are extruded core, but i am not sure about the other poplular kits. i've emailed greddy, bt no response. ive alos called and was told that i needed to speak to a tech, and there wasn't one in at the time i'll try and get ahold of the other manufacturers and get some data as well."
I would try the mailing list you may be able to get more info from there.
yes it is just rough numbers but you can roughly calculate lag. Those numbers are external volume, when internal volume is what you need. Remember you also neeed to take into account the size of piping into total volume.
Because most aftermarket intercoolers roughly have the same surface area, I doubt there will be any (or much) difference in efficiency. But the larger the volume of the intercooler the greater the pressure drop.
People have made 550rwhp + through the stock smic. The Greddy 3-row has supported 900rwhp +.