I know that a FMIC is usually running a cooler temp that a conventional because its not subject to the under the hood temps. But I also hear that the FMIC has a pressure drop because of its size, so which one is better?

 

It depends on what you intend to do with the car. My personal opinion is that a FMIC is probably better for street use and drag racing, but hinders engine cooling and is thus not a good choice for road racing (open track events, etc.). I run a SMIC (stock mount IC) because I road race.

Whatever you choose look at the internal flow area and core construction (some core designs flow significantly better than others per unit area) to get an idea of the pressure drop. Long pipes increase lag, and ones with lots of bends increase pressure drop, too. End tank designs are important, too, with ones that flow well and promote equal flow through the whole core being ideal. Unfortunately, you won't find a single IC that is great on all counts, but this should help you evaluate what is available.

If you decide on a stock mount IC, the M2 Medium or Large and the SR horizontal are all good choices. There are a lot of SMICs that aren't so good for one reason or another (small core, lack of ducting, etc.).

Most FMICs tend to be reasonably well designed. A'PEXi, Greddy, HKS, XS, turbostreetfighter.com ones are all pretty good.

-Max