[Charlie]

An update, I managed to get two sport+ gears, a 27t and a 29, I have used the smaller one for now which is giving the car standard gear set up, now I have a spare gear and axle set up, what pinion should I use to get somewhere near the 9/27 ratio?  I thought maybe a 10/11 tooth pinion ? Or should I try it with a 9 , track is 100 feet with two straits, longest about 12/14 feet ?
Ta