they cant handle the voltage unless you completely coat the armature in epoxy, otherwise the rpm will destroy the windings. next issue will be the pressure relief valve, even when it is tightened all the way, there is a 2nd and 3rd backup. the 2nd back up is built in, the 3rd is basically a controlled leak. after that, the gasket or seal will basically blow out of the pump. these pumps are only designed to make a maximum of 2400psi. even if you fix or modify every weak point, it will eventually fail in the end. keep in mind, the Pesco pumps we use are late 1930's tech. it wasnt until the 1950's that pumps were able to produce 3000psi without seal failure.Thanks. Will anything over 48 volts make them go faster and can they handle the voltage?