Ah..... that's simple!
The Mychron 'knows' your revs and it knows what the revs were over VERY short intervals. Let's guess it 'memorises' them every 0.5 seconds.
It therfore 'knows' how MANY revs you managed to increase-by in EACH of those 0.5 seconds.
If you looked at your revs at 3000 rpm and, half a second later they were 3010, and you then looked at them at 12000rpm and half a second later they were 12020 rpm, then you could make an educated guess that you must have had DOUBLE the power at 12000 rpm that you had at 3000 rpm as you'd managed accelerate at DOUBLE the rate!
It needs two further data item (Entered at 'set-up):-
* The gear ratio * The mass of you and the kart.
Now, power is measured by the AMOUNT of acceleration in a given time. The Mychron 'knows' that from the rate at which the revs increased every half second. It also knows the MASS that the engine has accelerated. It can thus 'calculate' how MUCH power was used in accelerating THAT kart by THAT much in THIS many seconds.
'Simples!' (click!)
In truth, the gear ratio is NOT important for this calculation so long as you don't CAHNGE it between tests.
Let's assume you are test two carbs. You do the first test, look that the power curve, change the carb and look at the second power curve. You will see WHERE the power curve has changed. Without telling the Mychron the gear ratio, it can STILL show you that the SHAPE of the curve has changed. The 'numbers (i.e., 15 or 19 bhp) may NOT be accurate (if the 'weight' or 'gear ratio' you entered is wrong).... but who CARES when you can see that carb B is FASTER than carb A?
Ian
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