I have a 1998 GST and when i run it hard the collant seems to boil and steam really bad... I will list my mods to the car and maybe you can help me out with keeping it cool...

Force Performance EVO III Big 16G turbocharger ported
XS power front mount intercooler (FMIC) 24"x12"x3" end to end is 30.5"
inlet/outlet 3" rated for 700hp
injen intake
Fidanza aluminum lightweight flywheel 7 bolt
ACT 2600 MB1XTSS extreme clutch
Greedy Trust exhaust system turbo back
3" down pipe
External o2 dump
Greedy FMIC pipes
NGK spark plug wires
Prothane motor mount
255 LPH Walbro fuel pump
1g head w/ cometic head gasket, and intake manifold
steel braided clutch and oil line
ARP head struts

I was running it at 21 psi until it started over heating now i turned the boost controll all the way down... PLEASE HELP IN ANY WAY... thank you for your time...

I don't know much about the turbo models but since you originally posted this in the non-turbo section i'll give you some suggestions. Try getting a thermostat that opens up at 160 degrees, changing to a higher psi cap, adding some water wetter to your coolant, check to make sure your fans are working, burb the coolant system, and maybe wrap your turbo and downpipe to keep temps down inside the engine bay.

With a large core FMIC, you need to get creative with some ducting to get more cool air to the radiator.
When I installed my E316G, the J-pipe didn't clear the fan on the drivers side and I had to remove it. I had issues when the car wasn't moving enough for air to flow through the radiator and had to shut the car off at stoplights to keep from over heating. When it was a REALLY hot day, there was nothing I could do to keep it cool even when highway driving and had to leave the heat cranked.
I installed a SPAL fan wired to run all the time to pull air through which helped a ton. You could also get another mounted on the front of the radiator wired to push air if the additional pull fan is not enough.
Good luck! Large FMIC's always cause this.

thank you both... any help is greatly appriciated...

airflow is your problem. get some nice flowing fans and you should be ok.

any suggestions for type of fans?

get it here, you can get 12' for $40 that pulls/push 1600cfm cant beat that. i have two of those.
http://www.vsracing.net/catalog/index.php?cPath=48&osCsid=4c19560fe5067ab9d5854fc2f11d256c

thanks