Hi
Find speed of Grand Prix Car ?
Info I've got upto now, all values are just guess such as gears so if you know of any more accurate
stat's they would be welcome. I need all this info as I am trying to program an accurate dcar
simualtor
for my final year project in computer science. The Question is at the end of the message.
WHAT I HAVE.
Car : F1 Car.
Weight 600 kg ( including driver and fuel ).
Cd = 1.1 ( determined by the wing angles and basic shape of the car ).
Wing Area = .
Max Revs =15000 rpm.
Max Bhp = 800 bhp.
Wheel radius = 0.2 m, tyre coefficient 1.8 ( slicks rought guess )
Engine Efficiency = 0.9 per cent.
Gear Ratios = 1st 4:1, 2nd 3:1, 3rd 2:1, 4th 1.5:1, 5th 1:1, 6th 0.8:1 ( note these are not
accrurate values)
final drive ratio = 3.44:1.
Taking Torque = ( 63025 * bhp ) / rpm ( units torque in pound-inches )
Converting to Newton metres :
1 meter = 39.37 in.
1 newton = 0.255 lb
1 N -m = 8.87 lb -in.
Therefore
Torque = ( 63,025 * bhp ) / rpm * 8.87
( note 63,025, what is it from ? )
Any given instance of the car we know the revs the gear and the bhp, so we can find the spped of
the
wheels and the torque of the wheels.
for example where in gear 1
Overall gear ration = Gearbox ratio * Raer-axle ratio
= 4 * 3.44 = 13.76
speed of raod wheels in 1st gear
= Engine speed / Overall gear ratio
= 5000 / 13.76 = 363.3721
Linear Speed of road wheels
= Anglar speed * Circumferance
= 363 * 2* pie * 0.3 m/min
= (363 * 2 * pie* 0.3 * 60) / 1000
= 41 km /h or 25 mph ( note mile = 1.609 km )
Now finding torque of wheels
engine torque = ( 63025 * bhp ) / rpm * 8.87
we know revs at 5000 rpm so Bhp = 400
given that torque = ( 63025 * 400) / 5000 * 8.87
= 568.43 N m
Finding torque delivered to rear axle.
= engine torque * Overall gear ratio * Efficiency
= 568.43 * 13.76 * 90/100
= 7039.44 N m
The differential divides the torque of the final drive equally between each axle thus,
= 7039.44 / 2 = 3519.72 N m
Now I know the rotation of the wheels and the torque
wheels = 41 km/h
torque = 3519.72
given the weight, downforce and drag how can I find velocity
Now follows a brief Dig of a F1 car :)
_________
dirving force rear wheels <= = |_________| ==> Drag
| Downforce + weight the center is the center of gravity as well
Now the Question.
The Problem How can I find the speed of the veichle from Torque in each axle and the speed of the
axle, compenstaing for drag and downforce and friction tyres, any help/suggestion would be welcome.
Thanks in advance
DaVe.
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