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Motorcycle inertia dyno picup

(@hutchycass)
Member

Hi, first time on this site and first time owning a dyno with YourDyno system, i purchased it at the beginning of the year and had nothing but problems after problems, the rpm pic up, or display, is erratic and all over the place, when using with a bike, and found that the roller when spun pics up, as if it was RPM!!!! so program is receiving that as an rpm as well as the actual rpm picup has anyone else had this problem?  thanks 

This topic was modified 2 weeks ago 2 times by Hutchycass
Quote
Topic starter Posted : 08/05/2022 6:10 pm
(@admin)
Member Admin

Hi 

Engine rpm is roller rpm * gear ratio, this is how it is supposed to be. A direct engine rpm measurement is optional, and anyway is way too low update rate to use to calculate power and torque.

You set the gear ratio in the RPM setup window, using the tacho for example. 

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Posted : 08/05/2022 11:42 pm
(@admin)
Member Admin

Snip from the software manual:

2.3.2 Gear ratio setup

The Engine RPM control in YourDyno system is based on the Roller RPM signal from the Hall-Sensor. There are many reasons why the actual Engine RPM (for example from OBD2 interface) cannot be used to correctly control the dynamometer. Mainly they are too slow. Since all roller dynamometers measure torque at wheels, it is important that the Gear ratio is correctly set. Otherwise, the Engine Torque reading will not be correct.

In the Gear Ratio Setup tab you may choose between multiple ways of determining the actual current Gear ratio 

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Posted : 08/05/2022 11:46 pm
(@hutchycass)
Member

@admin hi thanks for the reply appreciated very much, so it’s how it’s supposed to be? i was driving myself and trying to find a problem, so it’s calculating power and torque through roller RPM and gear ratio? not Engine RPM? can i have it so that it reads RPM actuarially? as the pic up that i have is jumping about all over the place  

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Topic starter Posted : 09/05/2022 12:10 am
(@admin)
Member Admin

Yep, it uses the roller RPM. Engine RPM is calculated from that and gear ratio. I recommend getting everything to work with just that first, as this setup is very simple. You can add a direct engine RPM measurement later if you want, but the only help from this is that it is easier to set the gear ratio, plus you can detect slip. The dyno still uses roller RPM for all its calculations.

So get up to 4th or 5th gear, hold a set RPM (like 2000 or 3000, whatever you set in the Gear ratio window) and press Lock gear ratio. The RPM will be stable, unless you have an RPM sensor or trigger wheel problem. 

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Posted : 09/05/2022 1:20 am
(@hutchycass)
Member

@admin thanks for you’re replies are very helpful, i i am still having issues unfortunately so i downloaded the latest version for it from the site and now it disconnects itself as soon as i start up the bike on the dyno, the computer that i am using states that it’d disconnected driving me crazy 

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Topic starter Posted : 10/05/2022 10:17 pm
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