on a front mount ?
wouldn't bother, the engines fan helps a fair bit. trouble is the fan can also block air flow and it needs cowling to make it effective.
air con fan is fairly small, i thought the intercooler was bigger ??
plenty of aftermarket fans which may be easier to fit. the other thing is what do you use to control it.
You might find a misting system would provide more benefit, Dave. Moisture on a surface will cause the surface to cool as it evaporates and provides a greater heat exchange rate.