I was given a puzzle today, a friend wanted to know how fast a stock 1986 auto corvette would go in top gear at 3000 rpm and inversly what revs would be required to do 140 mph.
So firstly we had to define the specifications of the vehicle located here
Http://auto.howstuffworks.com/1986-corvette1.htm
Then we need to know more info on the wheel tyre package
Http://www.1010tires.com/tools/tire-size-calculator/205-75r15/235-70r15/225-65r16/235-60r16
Given that the stock specs for an 4spd auto 86 vette are:-
2.59:1 (auto) 3.07:1 (manual)
Tyre 225/60 vr 16 = revs per mile: 755.93
shall we start?
Lets start with the vehicle speed @ 3000 rpm
@ 3000 rpm/ 2.59 = wheel rotation = 1158.30
1158.30 / 755.93 = 1.53 miles / minute
1.53 x 60 = 91.93 MPH
( assume it has the manual diff @3.07 / 3.07 = 977.20 / 755.93 = 1.30 mpm x 60 = 77.56 mph)
pretty simple right?
Ok lets go the other way
140 x 755.93 = 105830.2 / hr
105830.2 x 2.59 = 274100.218 rph
274100.218 / 60 = 4568.34 rpm
now there is some dispute regarding my calculations based on my extensive knowledge of mechanical physics and maths so have an opinion and speak up