Kyosho IG113-20 20T 2nd Pinion Gear Inferno GT

A 20 tooth second gear pinion for the two-speed transmission on Kyosho's Inferno GT.

A two-speed gearbox shifts automatically at a set engine speed, and the second gear pinion determines the ratio the car runs in once it has shifted. That makes this a genuine tuning part: a smaller pinion gives a shorter second gear, so the car accelerates harder after the shift but tops out sooner, while a larger one stretches second for more top speed on a circuit with long straights at the cost of some punch out of the shift.

Kyosho supplies this range in several tooth counts precisely so racers can match second gear to the track rather than accepting one fixed ratio.

Getting the mesh right on installation is critical and it is easy to get wrong on a two-speed, because the gear only engages under load. Too tight and it binds and runs hot; too loose and it strips, usually at the worst moment.

Kyosho lists this for the Inferno GT, with dealers extending fitment to the GT2. Note Kyosho's own page carries a spelling error in the part name.