# Calculators

# Scale and offset calculator

For use with Analogue Input Modules. Use the calculator below to work out your scale and offset values.

### Analogue Input Calculator

See the guide for installation and setup of the Micro Input Module here**.**

### Typical RPM scales

Cylinders | Scale | |

1 | 120 | |

2 | 60 | |

3 | 40 | |

4 | 30 | |

5 | 24 | |

6 | 20 | |

8 | 15 | |

10 | 12 | |

12 | 10 |

Typically an RPM signal from an ignition coil will need to be scaled to get an RPM in the form: RPM = f *60* 2/cylinders.

This is because Input Modules gives pulses per second which we need to convert into revolutions per minute.

E.G. 1 pulse per second = 60 pulses per minute x 2 (2 revolutions of crankshaft per combustion of spark plug) = 120 divided by the number of cylinders (4) = revs per minute (30).

So, for a four cylinder engine it would be 120 divided by 4 = 30.

Try these values as starting points.

# Gear display range calculator

To display the selected gear in a VBOX scene, you will first need to log a data file with speed and RPM included in it.

To help determine which ranges are then required in your display range element, enter the RPM and GPS speed at a given point in each forward gear and click "Calculate".

A helpful guide for setting up a gear range display element can be found here.