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Top Speed App

iPhone / iPad
  • Entertainment
  • Education
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Top speed app is used for calculating an automobile's top speed, gear ratios, engine RPMs and tire sizes.

Top Speed App is for educational purpose only and the results should be confirmed
with other technical data and or calculations.
Top Speed App should not be used while driving.

Using top speed is easy and the results are very useful when dialing in tire sizes and gear ratios for your custom car.

Instructions: if you know your tire size press the Input Tire Size button at the bottom of the main screen.  It will take you to the screen which allows you to enter
your tire specifications.  

Enter your tire specifications in the input tire size screen.  This will figure out the tire diameter and width of your tires.
The results on this screen can also be used to help determine tire heights and width when comparing different tire profiles .

Note : The results should be compared to the tire manufactures data, as different tire manufactures might not use the same calculations to get tire
dimensions (width and height ) from the tire profiles.

After entering the data press home button on the
lower left corner.
This will take you back to the home screen which has the sliders and displays the result of your tire diameter in the tire size slider.

Once your back at the home page you can select what ever parameter you wish to get results for. In this case the picture displayshow Car Speed was selected.  Move the sliders to your cars specifications.  Desired Engine RPM in this case 2985, the current gear ratio is 4.11, since the transmission is a manual transmission which is in final drive with no over drive it is at 1.0 (the transmission
ratio defaults to 1.0).
The tire size, diameter was already calculated in the first step, however you can move the slider and not use the tire size input function .
The speed of the vehicle with these parameters is 65 MPH.
By moving the rpm slider or gear ratio slider you can determine your cars top speed based on max engine rpm with given gear ratios.   Press reset
button to reset the sliders to zero. By going to the input tire size screen your previous slider inputs will also  go back to zero.
Note: when you make a selection that slider which was selected (in this case Car Speed)  is locked out till you press the reset button.