86 Club Car 36 to 48v

[blue water massey]

What would need to be done to convert from 36 volt to 48 volt.
I'm looking to get more speed out of this old cart and not sure if it can be just jumped up to 48 volts.
Would the system take the extra voltage or am I just asking for trouble in a short time.
I have a 48v charger and the batteries, adding two more isn't to hard as there's space there.
The controllers on this cart is 5 36v solenoids with 3 resister coils, stock rear axle and motor all from the 86 Club Car.
I think the speed controller is 5 micro switches from the wiring diagrams posted in the tech stickies.
I used the wrecked 86 Club Car drive line in a 79 Cushman Executive body with a fried system in order to get it going again and parts are easier to find.
As this body is heavier than the donor cart speed suffered mostly on hills.
It's the wife's campground cart and gotta keep her happy.