When torsion bar springs came into LMP design with cars like the Bentley Speed 8 and the Audi R10, they used torsion bars front and rear. However, starting with the 2012 Audi R18, the use of coil springs at the rear became common on factory developed cars, and has carried though to the LMH/GTP era of the present day.
Is there a reason for this occuring? I've been told that one issue that the R10 had (at least for a while) was torsion bar "twist" that happened at the rear of the car when the engine bay got hot. I wonder if/how that issue was addressed, and if that lead to the use of coil springs at the rear of LMP cars becoming common again.
