Ridge claims a 125F temp. drop.
I'm not certain how hot the compressed air is before entering the intercooler. The same volume and pressure cooled by 125F assuming an initial temp. of say 275F would yield an increase of about %10 air mass. Lower initial (pre intercooler) temp., would result in a larger air mass increase. (1.10nR x 373K = 1nR x 411K)
So how much does the turbo heat the air to begin with?