by Dave-R (Roppa440) » 09 Apr 2002 14:51
The output ratio in top gear is 1:1 but I use 1.08 on the spreadsheet because a convertor always slips to some degree. A good one will slip less than that but I have found 8% to be a pretty good average. I also add a half inch or even an inch to the tyre diameter when working out rpm or speed to make up for tyre growth at high speed.