How big does an intercooler have to be to support 400hp?
 

Like the tittle says how big, my current ic is 33"x6"x2 1/2" is that big enough? right now it's doing 250hp.

Re: How big does an intercooler have to be to support 400hp?
 

is that the size of the complete ic or just the core ?

speaking of the core size only, according to the garrett intercooler sizing chart, for 400 hp with a 2.5" thick ic, it would have to be at least 8" high.

if your's is just 6" high rather than 8", i think it will flow no more than other 2.5X6 intercoolers, that is, around 300 hp.
I think that's regardless of the lenght. if your core is really 33" long, it should improve only the cooling, no the flow.

plus, bear in mind the garrett chart is for their intercoolers (spearco). If you have a 99$ chinese intercooler, depending on the actual design of it, you may need an even larger core to match the flow of an authentic spearco.