[s-cars] launching an rs2 with blocked diff?

[Sla]

dear all,
i have really silly question concerning drag racing:). your opinion is
really welcome. what is better, to launch  car with blocked rear
differential or with free diff? is there any possibility to brake anything
under heavy launch with block differential? the car is really powerfull
(rs2, 380 hp) and expensive, so i do not want to brake anything;).
thank you in advance

sla s2