If you have an intercooler internal leak you can over temp the circuit. Are you seeing the coolant level drop a little? If it's a leaking intercooler you will be pumping air into the circuit while into heavy boost. Cruising around your car will be sipping the coolant. If the leak is serious you should be spraying coolant out of the reservoir cap ..... well, it depends on your reservoir and how long your boosting. Mine was a BMW power steering unit. Keep an eye on the level in the reservoir and look for signs of flash dried coolant. The other way to know is to pull one side of the manifolds and look for goo. Any at all and that's your problem. It does sound like intercooler circuit related. Lots of air in the circuit, bad pump, serious I/C leak are the most likely places to look first. Double check that pump just in case.

Les