Toyota Supra Mk4 Top Speed
Theoretically, and according to this graph, a stock gear stock tire 6spd supra should see 300mph in 6th gear at 10,000rpm (which is usually the shift point for race prepped 2jz's):
The question is what is the minimum power required for a supra to maintain 300mph?
Well, if you think about the horizontal component forces on a supra at 300mph, you will see that aerodynamic drag is the only major one. A counter force is needed to match the force of the drag. Otherwise, if the counter force is greater, the car will accelerate further. Conversely, if the counter force is less than the drag force, the car will deccelerate from the power deficit.
Drag Force = 0.5 x air density x Area of front of supra x drag co-efficient x (Velocity)^2
Drag Force = 0.5 x (1.23KG/m^3) x (2m^2) x (0.32) x (133.33m/s)^2----------[velocity was converted to metric]
Drag Force = 6997 N
So this force of 6997 Newtons pushes the car back, creating a torque moment on the centers of the wheels that tries to push the tires the opposite way resulting in slowing the tires down. So, a counter force of 6997 Newtons must applied through the power train to keep the wheels spinning at that constant speed.
Now we know how much force we need to apply a counter torque moment on the wheels, so we can find the torque as so:
Torque = Force x half the distance between the center of the wheel and the pavement
Torque = (6997N) x (0.13335m) <---------Roughly
Torque = 933 N.m
Now we convert from N.m to ft.lb:
(933N.m)(0.73756(ft.lb/N.m)) = 688 foot pounds to the wheel
And finally using the HP-Torque-RPM equation yields the needed whp to maintain a maximum velocity of 300mph in an MKIV 6spd Toyota Supra:
HP = Torque x RPM / 5252
HP = (688ft.lb)(10,000rpm) / (5252)
=====> HP = 1310whp
So there's your minimum hp requirement to travel at 300mph in a Supra, folks. Of course altering the wheel height, improving aerodynamics, and changing the gearing of the differential are all things that will help make that 300mph mark within shorter reach.
Source: https://www.supraforums.com/threads/highest-top-speed-with-a-supra.613681/
