Most accurate: Drive at 60 miles per hour on flat level interstate from one mile marker to the next, while running a stop watch. This value should be the same as control watch. But off by a minute. Whatever time you get, in seconds, divide by 60. That's the amount you're over/under. You set that as a multiple to the flux capacitor, but you have to remember that a Jigawatt and Gigawatt aren't the same, one's english and one is metric.
Err, wait.
You do the 60mph on flat level interstate, but watch your odometer, and see how many miles it gains in between one mile marker. Divide 1 by the number of miles indicated by your odometer, let's call that 'x'. That's how much you're over/under, based on the tire pressure, drag in your sixty year old speedo cable (if it doesn't make the needle wobble, it's broke!) etc. Then you pull the gear, count the teeth. Count them again. Then shut off the blaring rap music, Sesame Street Counting With The Count video game, and that blender making your margaritas, and count it again when the margaritas wear off. Divide your current tooth count by the number you got earlier, 'x', and that's what your new tooth count should be.
I think.
Example: your odometer increased by 1.2 miles. 1/1.2=0.8333='x'
Your current pinion is 40 teeth.
40/0.8333 = 48.000 teeth. So you need 48 teeth.
Or maybe you multiply it. 40*0.83333= 33 teeth
Did I get that right? What do I win? I can't think with all this rap music.
