My experience is high boost turbo mountain sleds focused on rigorous mountain and chute climbing. Under such stress, I have seen engine after engine failure over the years of stock polaris motors and other manufacturers. The majority of polaris failures were piston related. I have personally pulled several sleds out with only 500 to 1000 miles on a set of pistons, not good. Premature failures I have seen included skirts breaking off and falling into the case, broken ringlands, ring failure, and cracked cylinders and cases. For those who went the factory route to rebuild, similar issues happened again later.
In more recent builds, those who used fix it kits; albeit rk tek, mountain tek, or other; premature failures were reduced. Those kits do use forged pistons, but, at this point, both companies mentioned have the issues worked out. Also, I know the mtn tek kit uses cylinder spacer that increases case volume, which helps turbo motors in a variety of ways. The biggest problem for any motor is heat. Any additional case volume helps with thermal management.
Finally, forged aluminum is stronger than cast. But, tolerances are different for those pistons and they are more likely to cold seize if you do not allow for proper warm up. Regarding the pistons themselves, the pistons are designed to handle more abuse than what polaris spec'd the factory pieces for. But keep in mind, polaris is tasked with building cost effective sleds for the general public, not people like me who push them to the limit every ride. Of course the sleds built by myself and those I ride with required different components. Sleds with double or triple the output of factory tend to break parts...that is the game we play.
