I've driven JM turbo Coopers S42 HP about two weeks, and the experience is good.Much more "practical" power and torque.I spoke with the ECU tuner , and he warned the increased cylinder pressures.He urged to visit the dyno and told to reduce slightly high revs ignition timing,for sure.I did not know the problems with rods, but weak pistons I have read.I'm about to install OCC also reduces the possibly to pre-ignitions.Hot oil mist ,high cylinder pressure and increased boost temp may cause of knocking .Difficult to detect, and is sure to strain the engine internals.