I have finished changing my radiator today,made a duct(big hole) in the bottom of the nose cone and made some alloy deflectors to direct the air in, Ive managed to slice 30degrees off my running temp under serious load!!! got to put a stst in now but I don't mind also plumbed the cooling system up different and it works great.

Well done mate, Now you can fit an even bigger turbo!

Yay! So the airflow WAS the culprit!
I was going to suggest spraying the intercooler with Methanol next - that'll certainly cool it!

Any pictures of the mods Andrew.

I dont know much about kit Cars but on my MR2 Turbo the water injection made a huge difference you might want to consider it.
The methanol it is a good solution mostly for drag racing cause it does cost to refill it and it does need to refill it more often that you think.
I found that if you heat insulate the turbo unit does make a small difference on lag