Dwight, his speedo is probably off some; seems most are.
Anyway, look at it this way - a 295/50x15 tire is 26.62" in diameter (
www.rogerkrausracing.com/tiredem.html), which works out thus: 26.62" x 3.14 divided by 12"/ft = 6.96'/revolution
Now....1.34 (3rd.gear) x 3.27 rear = 4.38 drive ratio in 3rd. gear; 6500 rpm divided by 4.38 = 1484 revs/minute, divided by 60 seconds = 24.73 revs/second.
So. 24.73 x 6.96' = 172.1'/sec, x 0.6818 =
117.3 mph, not too far off that SecondStrike calculator.
But - go to a 275/60x15 tire, which is 28" in dia (actually, 27.9" - I cheated and rounded up), and 7.32'/revolution, and your final calculation here winds up being
123 mph - which is admittedly a ways from 130 mph, but who's looking at that speed anyway?
Hey, Jarendall, when you find a decent stretch of road....................ah, never mind.
