24th-Jun-21, 11:09 PM
Hi Johnno,
Some styles of tachs use reflective tape to get a signal. Installing a small piece/strip on a tire sidewall or tread will tell you wheel RPM at a given voltage. Hold the car in your hand and power it up. Use the tach and multiply the number by your gear ratio and you're all set to start taking/recording motor RPM readings. Keep your voltage the same from test to test.
7000 RPM at the wheel is 21,000 at the motor with a 3:1 gear ratio. Time to get the calculator out.
No need to take a car apart to test final motor RPM.
Cheers,
Ken
Some styles of tachs use reflective tape to get a signal. Installing a small piece/strip on a tire sidewall or tread will tell you wheel RPM at a given voltage. Hold the car in your hand and power it up. Use the tach and multiply the number by your gear ratio and you're all set to start taking/recording motor RPM readings. Keep your voltage the same from test to test.
7000 RPM at the wheel is 21,000 at the motor with a 3:1 gear ratio. Time to get the calculator out.
No need to take a car apart to test final motor RPM.
Cheers,
Ken
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