The Kyosho Giga crusher has a 3-speed system as also the Schumacher Fusion, both cars have a clutch with 3 gears and directly on that the 3 speed gearbox. The 3-speed of the savage is a middle shaft gearbox.
Else you have to take a look to the old BMT 3-spead gearbox and from what I have seen in my early days a Collari car was using a 4-spead gearbox made with a 4th set of gears on the excisting 3-speed BMT gearbox. (the BMT sitem can be stapled with as much you want)
Speed is only fiction but a 130+km/h MRS4 is for real.