Joined: 16 Mar 2008
|Posted: Sun Mar 16, 2008 2:40 pm Post subject: Vehicle thrust introduction
Attached to this site (see the links above) there is an application for taking in torque figures and gearing for vehicles and from that displaying a graph of thrust through the gears.
Acceleration is largely down to the thrust, along with weight and wind resistance. So far I have not done anything about calculating the drag due to the wind resistance.
The graphs are generated on the fly (which unfortunatly means that most forum software will not let you directly display them as an image, athough you can just save the image and upload it as a jpeg to display).
You can enter details yourself for any vehicle you want. When you have finished fiddling you can either keep it to yourself or you can mark it for public use. If you keep it to yourself then only you can view graphs for it, but if public then anyone can.
To enter the details for a vehicle you will need to know the driving wheel size, tyre size, tyre profile, primary drive ratio (with cars that will normally be 1), gearbox ratios and final drive sprocket sizes (diff ratio). You will also need to know the power / torque through the rev range. The more points the better. The application takes power or torque in either imperial (lb/ft & hp) or metric (Nm & kW), although it is converted to lb/ft on input. You can enter the rpm or (if you have entered the gearbox ratios already) speed in mph / kmh that the figure was recorded at (as long as you know what gear it was recorded in).
On the final graphs you can adjust the final drive ratio to see what effect it has on the thrust at different speeds.
You can overlay up to 10 vehicles thrust graphs over each other (or you could overlay the same vehicle 10 times with different gearing).
Thats the basics of it anyway.
All the best