[bm49]

Thanks for the responses guys. I recently tried my new NT01's at a club track day held at the Sydney Motorsport Park Gardner Circuit. Using 32 psi hot they felt reasonable but the wear patterns, particularly on the most heavily loaded tyre (front right), look like the pressure was a bit low.
My car is a fully log-booked 2008 135i coupe with a National spec roll cage, KW Clubsport coilovers and 245/40x18 tyres on style 261 8.5" rims in a square setup. As it is also a full road car apart from the cage, bigger brakes, competition oil coolers, race radiator and race seat etc, I suspected it would be bit heavy but was shocked to check it on the track scrutineering scales and the reading was 1611kg with a half tank of fuel and no driver. A friend also checked his similar 2008 car on the same scales. His car was fitted with the Nitto tyres but is in a full road spec and came in at 1515 kg also with half a tank of fuel.
I guess all the gear adds up when you do not strip the car but the additional safety is nice and I can now run the car flat out in long sprint races without experiencing the dreaded limp mode associated with excessive oil and water temps.