gearing help needed ..fdr .. tf-5

[shaun m]

hi im after some gearing help .. for the track im gonna run on i need a fdr of 5.5 -6.0 .. .. it has a 68 spur and 36 pinion and im running a nosram 13.5t motor , ive looked on gearchart.com . but i cant seem to load the screen up ... please help ..

originaly it had a 20t brushed motor ....but ive been told i need help , but not medical help this time ..... just gearing ..