i used to run a pace charge cooler on my sII running 16 psi ... suffered from heatsoak really badly with the standard water rad they supplied..
its worse when slow moving in traffic temps climb really high but once you get clear air it soon drops..
the water gets to a temperature where it will not cool enough to to keep the air charge low even when moving .. hence the need for more water .. and bigger rad
alot of people say avoid and get a larger intercooler .. i can remember some even having huge resevoirs of water to try and keep the temps down and bigger rads .. but changed to a better intercooler ,
alot of waffle and rambling .. but i just woke up