Thanks for your input guys...
I'll be putting a heated windscreeen in so hopefully that will avoid steaming up while on the track... I don't have room for a heater anyway - not the huge heater that came as standard in the mk1!
So, to bypass the heater matrix... what would you think of this theory?
Blank off the outlet from the water pump that would usually feed into the matrix and blank off the the inlet located on the head by the water temp sender.
I plan on running an oil cooler so the standard modine will be removed..
The reason I asked about water cooling through the turbo is that I've heard that it can increase the running temp significantly on the YB? Would be best to keep this down as much as possible if I can!