when a manufacturer says that an intercooler is god for X amount of horsepower, how do they dteremine this? i im looking for about 400 whp next spring, so i must replace my current one.

i find it odd because i thought it would be based off of psi and ususally they say pressure test up to 80 or more, pnding on the maker. so some one enlighten me on this topic

 

A certain hp will require a general mass of air. How much depends on the efficiency of the motor, but generally speaking there's average numbers you can use. So, you have to cram a mass of air through this ic. There will be a pressure drop across the intercooler if it's small and you're trying to cram a bunch of air through it. A bigger ic will flow more air. Of course there is a lot more detail to it, but you get the picture.

 

so, technically its not so much horsepower, but the amount of pressure your pushing through it and at what speed?

a lil off topic, whats a good sized intercooler that will fit in a 95 civic? mine is 6 high, 31 long, 3 wide. would it be hard to fit an 8 incher in there (no pun intended)