Originally Posted by wwjd15
Everytime switchs to R-comps, suspension and chassis have to be retuned. It wouldn't work well if you just throw R-comps on a car. The reason why Z07+PSC's worth that many secons is more on the suspension side IMO.
Randy Pobst was one of their pro drivers and he said it was all about the tires - given his credentials I'll take his word for it.
I doubt the M3 suspension would need to be retuned to accommodate the M3 OEM PSCs and I bet they'll reduce lap times by at least two seconds.