is a 18x16x4 core overkill for 500hp? how big is to big?

 

I'm not sure how many guys on here are using a 4" thick core, or even if it will fit without too many mods. I would be curious how much pressure drop there would be on a core that size. Perhaps someone who uses that big of a core will chime in.

 

i have the space for it, im tilting the radiator back a bit and im going to put it in diagonally in the space between the radiator and the round bar. It will defenitely fit, im just concerned about hte pressure drop

 

Thats not very big.

In an ideal airflw scenario, I'd say 500whp is the limit of that I/C.

Thickness is not always greater then surface area. A 3" thick core with a 24"X 16" cross section will cool better then that.

Also, pressure drop has alot to do with endtank design. More so then the size of the core alone.

 

the greddy/trust 3 row is 4" thick. i have one in my car, and it fit just fine.

 

It's not overkill, but you could probably use a smaller intercooler if you would like. It's difficult to say though, since the construction makes a big difference in performance. You can read about most of the factors here:
http://www.are.com.au/feat/techtalk/intecoolersMR.htm

If you are extremely particular about response, then you want the smallest intercooler possible so as to reduce lag. Otherwise, an intercooler that is "too big" would not fit in the engine bay, so you don't really need to worry about that.

If pressure drop is a huge concern, then you would probably be better off with a horizontal-mount with direct-feed end tanks. Each 90deg tubing bend will incur about 0.15 to 0.4psi pressure drop in an average application. Also, you may want to choose an intercooler brand that publishes its pressure drop statistics rather than hoping that the nice sweat-shop folks did a good job making your cheapie E-bay intercooler.