I did some data acquisition at Autohbahn raceway in Joliet, IL yesterday.
This graph shows charge air temperature, both pre and post intercooler. This data is after 20+ minutes of full out running, and shows the maximum temperatures achieved in a 30 minute session.
Pre-intercooler charge air temperatures are the red and dashed-red curves (top two curves).
Post-intercooler charge air temperatures are the blue and dashed-black curves.
The dashed-black curve is without water/methanol injection, the solid blue curve is with water/methanol injection.
As you can see, the rls Intercooler alone took out up to 100 degrees F. The rls Injection took up to an additional 30+ degrees F out of the temperature.