Since JIm would rather mock than help you out with info (does he not know lol).....

888's have stronger sidewalls than the T1-R's, although if you used the T1-R's on track just whack more air in them to stiffen them up a bit..... it will make a big difference. The grip levels between 888's and T1-R's (or any normal road tyre) is like chalk and cheese on track (assuming it is dry).

As with most softer compound track tyre with a slicker tread pattern, you have to be very careful of heat.... too much heat and the tyre will go off very quickly and you will end up destroying it. Keep an eye on tyre pressures and adjust your driving style to be smoother.... they can last ages if treated well.

I have heard many people say "these track tyres are crap and go off so quickly". That is because they have no comprehension to what tyres pressures they should be running and drive like a cock being too aggressive on steering etc. You would be surprised how much quicker and tyre sympathetic a good driver can be. If you're scrubbing your tyres, you are losing traction and going no where fast.