What RPM Should You Be Shifting for Optimum Acceleration?
Here’s Engineering Explained‘s Jason Fenske back to teach us a little something about acceleration and optimal shifting points to facilitate that. This is a relatively complicated mathematical process for a short YouTube video to discuss, but he does a really good job of explaining it. If you’re at all engineering minded, check out the video and see if you can calculate your optimum shift points for your own car.
Jason uses his own Honda S2000 as the example, showing his torque curve and calculating from those numbers. You see, in order to optimize acceleration, you want to keep your car’s wheel torque force as high as possible. This means your upshift should occur at the point where the lower gear’s applied torque is equal to the next gear’s available wheel torque, or redline, whichever comes first. In the case of the Honda S200, wheel torque does not drop appreciably enough to warrant a pre-redline shift, but in other cars with a more bell-shaped torque curve, or for cars with closer ratio gearboxes, your shift may need to come earlier to make sure your acceleration continues as quickly as possible.
In order to calculate your wheel torque and optimal shift point, you’ll need to know the ratios of each of the gears in your transmission, the final drive ratio, any drivetrain loss percentages, your driven wheel’s tire diameter, your torque curve, and your redline engine speed. With that information, and the video above, you might be able to work it out with some serious math.
Chime in with your thoughts on the forum. >>
Via [Engineering Explained, Motor Authority]
