MrWretch

It takes the rear end gear ratio, the redline, the tire diameter, and the engine's max torque. It doesn't take air drag into account.

My S4 with mods-

$ ./gears.pl -e 4.111 -r 7100 -t 25 -q 380
gear 1 - 3.50:1, final drive - 14.39:1, max speed - 36 mph, 4647 wtq
gear 2 - 1.89:1, final drive - 7.77:1, max speed - 67 mph, 2509 wtq
gear 3 - 1.32:1, final drive - 5.43:1, max speed - 97 mph, 1752 wtq
gear 4 - 1.03:1, final drive - 4.23:1, max speed - 124 mph, 1367 wtq
gear 5 - 0.81:1, final drive - 3.33:1, max speed - 158 mph, 1075 wtq
gear 6 - 0.68:1, final drive - 2.80:1, max speed - 188 mph, 902 wtq

His stock 3rd gen Rx7-
$ ./gears.pl -e 3.9 -r 7000 -t 24.9 -q 220
gear 1 - 3.02:1, final drive - 11.78:1, max speed - 44 mph, 2202 wtq
gear 2 - 1.61:1, final drive - 6.28:1, max speed - 82 mph, 1174 wtq
gear 3 - 1.00:1, final drive - 3.90:1, max speed - 132 mph, 729 wtq
gear 4 - 0.69:1, final drive - 2.69:1, max speed - 192 mph, 503 wtq

His modded wrx-
$ ./gears.pl -e 3.54 -r 7000 -t 25 -q 270
gear 1 - 3.45:1, final drive - 12.23:1, max speed - 42 mph, 2806 wtq
gear 2 - 1.95:1, final drive - 6.89:1, max speed - 75 mph, 1581 wtq
gear 3 - 1.37:1, final drive - 4.84:1, max speed - 107 mph, 1109 wtq
gear 4 - 0.97:1, final drive - 3.44:1, max speed - 151 mph, 789 wtq
gear 5 - 0.74:1, final drive - 2.61:1, max speed - 199 mph, 599 wtq

Friends 3rd gen. supra-
3.91 rear diff, 6500 rpm redline, 24.60 tire, 435 ft-lbs engine torque
$ ./gears.pl -e 3.91 -r 6500 -t 24.6 -q 435
gear 1 - 3.25:1, final drive - 12.71:1, max speed - 37 mph, 4698 wtq
gear 2 - 1.95:1, final drive - 7.62:1, max speed - 62 mph, 2819 wtq
gear 3 - 1.31:1, final drive - 5.12:1, max speed - 92 mph, 1893 wtq
gear 4 - 1.00:1, final drive - 3.91:1, max speed - 121 mph, 1445 wtq
gear 5 - 0.75:1, final drive - 2.93:1, max speed - 162 mph, 1084 wtq

joec500

Pearl? or perl? :P ....sorry I am being an A$$

MrWretch

duly noted, thx

Island Boy::Jeproks

It's Perl. Gek stuff and not color. ; )