However, I have also found that when I tried to fly the plane over FL200, the Intercooler is not much help. It certainly results in a high temperature drop from CDT to IAT, but the temperature problem I have experienced is a high CDT, which the intercooler does not help with (it is downstream of the compressor).
The intercooler IS dropping the cdt temp by the value on the readout. Flip the switch on the intercooler guage to in ( should be the same as cdt) flip switch to out and record value. Put back to middle position for differential. The intercooler would do nothing in front of the turbo.
larry