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custom flywheel

EFI Wiring Fundamentals

Discussion and questions related to the course EFI Wiring Fundamentals

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In case you want to by an aftermarket VR sensor to change the oem in motorcycle, what do you need to check or change on the flywheel so the analog signal to be correct ?

With VR sensors the most important factor is the size of the pole piece inside the sensor relative to the tooth size on the trigger wheel. Ideally the pole is about the same size as the tooth. With some sensors the pole piece pokes out the end so you can check it easily, with others it is not visible but you can get an idea of the size by "feeling" it with a paper clip or similar (the pole is magnetic).

If the tooth is much bigger than the pole then the waveform flattens off through the centre of the tooth rather than giving a nice sharp zero-crossing so trigger accuracy is reduced.

Thank you very much.