PS - the ones in those pics have been left overinflated. Would guess you didn't let any pressure out once they had got up to temperature so you were running 45+ psi when hot.
I would be very surprised if fmp's tyres were running at anything like 45psi.
If we assume he inflated them to 30psi when cold (lets say 20°C), then due to the fact that the air in the tyres is governed by the ideal gas law (it does not follow it completely, but is close enough for this illustration), technically he would have had to have had the air in his tyres up to 166°C to get 45psi. Due to the fact that temperature induced in the air inside the tyre lags behind tyre pressure changes (due to the thermal mass of the rim), it would be safer to assume that the temperature inside the tyres was something like 120°C. This is an extremely high temperature to be seeing inside the tyres.
If I start out with cold pressures of 30 all round on 888s after about 15 minutes on track the pressures will be about 48 front and 40 rear.
I would love to know what you are doing to your tyres to see an 18psi increase in 15mins. To see this sort of pressure increase, the air temperature would have to be 196°C theoretical, realistically 140°C (based on the same assumptions as above). Extremely high performance road cars do not see these sorts of increases in such short time periods. If you are actually seeing this, it suggests you are over driving the tyres, being ott on the brakes (heat builds up in the rims due to heat soak from the rims, increasing the air temperature and subsequently the pressure, or a combination of both of the above.
would filling the tyres with nitrogen stop them wearing as quick ( ment to give constant pressure retention )? place near me does it for £1.50 per tyre...
Complete waste of time for normal road goers, or even for track days in my opinion. Only reason f1 use it is because of the very high temperatures they see, and because they go to some races with very variable weather conditions (specifically changing humidity) and can end up with a lot of moisture in the air, which is not what you want in a tyre which is getting very hot.
those in the pic i beleived where running 26psi, but i think in actual fact it was closer to 28psi.
That's interesting.
I've never had wear from wrong pressures like that.
Would be very surprised if being 28psi instead of 26psi was the sole cause of this problem. Did you start of with the FL lower in pressure than the FR, due to the fact Brands is predominantly right handers?
Having read you're taking part in Time Attack this year, have you invested in a pyrometer? It's a very useful bit of kit. It can be used for measuring the temperature at different points across the tyre, and if you have significantly different temperatures across the width of the tyre, this can trace this back to under/over inflated tyres, and incorrect camber settings.
How do they repsond with little or no heat in them? Less grip than a performance road tyre?
R888s with no heat in them will be terrible. These tyres are not meant to be stored in temperatures below 0°C due to the fact the rubber can become hard and crack. In normal use they will not become warm enough to soften up, and will offer significantly reduced levels of grip. So yes, they will offer less grip than a performance road tyre when cold.
Standard road car tyres start going quite hard when the ambient temperature drops below 7°C and the grip they offer drops away quite rapidly as the temperature drops below this. This is why winter tyres are used in places like Germany and Scandinavia, not solely because of the snow, but mainly due to the rubber on standard tyres going too hard in those temperatures.
As for recommended inflation pressures. Knowing nothing about the construction of the R888s, and going on the closest comparable data I have seen (comparing Corsa's against Zero's) and the recommended pressures for the same car, with the two tyre types, I would say MarkCup is bang on with his settings of 28psi front, and 26psi rear.
but it was good fun 
