I think this whole thread is a lot of generalizations. Again, you need to see what you're going to be using your car for most and what your goals are. If you are going to drag or make a stop light racer (not advoacating street racing) then you'd probably be better off with a FMIC as these WILL yield the highest potential horsepower (top end/fully spooled turbo/WOT). Maybe you like autocross or you like taking your car through twisties where you need low end responsiveness and may not get the chance to push your car in the upper RPM area where a FMIC would be advantageous. Basically, pick the one that would give you and advantage for most of the time you use it. We all wish we could have the advantages of both.

 

^^ Good point!

 

Hey man. I lived in Cecil Country for a while. Represent M-land!!!!

 

The WRC cars actually do have the advantages of both; they mount the intercooler in a "v-mount" configuration, with it near the very front of the car but raked back so that it flows air in both low-speed and high-speed situations, and more importantly so it doesn't block airflow to the radiator itself (one of the hazards of a FMIC, as anyone modding a Supra will tell you). As we don't drive WRC cars, our options are a bit more limited.

The real deciding factor, as you pointed out, is peak hp. vs a streetable car. By the time you really need a FMIC, you should have upgraded your turbo to something truly monstrous (T67, FPGreen, SR-series), which means you have already resigned yourself to turbo lag, outrageous fuel consumption and a car that is generally a pain to drive around town . The more streetable turbos (VF34, VF37, VF22) don't need a FMIC; an upgraded TMIC/scoop/splitter/seal is totally adequate. You can get a STI to 310whp (385-390 flywheel) without one, just a turboback and a reflash.

 

I wasn't going to get into v-mounts as that's a little more complicated. They still have the excessive piping issues. And a lot of rally cars aren't v-mounts, they just mount the IC up higher (behind the Subaru emblem in our case). The Green isn't really a monstrous turbo nor are the SR series turbos, the DR series is the big one. Anyway, not trying to prove you wrong on anything just clarifying.

 

The reason I mentioned the Green, SR etc. is because those are really the biggest you want to mount without touching engine internals. If you really want to run a DR55 (i.e. shooting for 450+ crank HP) then choosing an FMIC is the least of your concerns at that point -- you've already committed yourself to a host of other upgrades besides, and are going after Vipers and Corvettes at that point, so the FMIC is a no-brainer. I'm just talking about those who want to keep the car streetable yet add power.

 

I worked on an inerview with Reeves Callaway regarding the development of the Alfa Romeo GTV/6 Callaway Twin Turbo. He stated they tried several different turbo/intercooler configurations, but settled on twin turbo with a top mount intercooler with a scoop as they felt it provided the low end power and throttle response they were looking for. One of the major goals of the project was explosive power off the line, and this is the configuration they settled on over others that may have yielded higher peak outputs.

It's interesting to see many of the same points Reeves made being discussed in this thread - especially cosidering the development for this car was being done in 1984.

Joe

 

Would you say our posts are generally in line with on of the best automotive engineers in the world?