hi very good video , i'm making my own dyno for motorcycle but i have a problem , i d'like to run 50 cc scooters and also over 1100 cc motorcycle but my roller only do 30kg ( D 320mm x L 300 mm) if i put a brake on it yoy think i'll be ok? thank you
So you're recording from 6 to 9 going full inertial and 9 to 6 loading it, then comparing to find and exact match between the two? This is done to get accurate real life readings right? This has to be done with every different vehicle?
Yes, you go up then down in RPM on the same run. It can be fully inertia or braked on the way up. Another way to do it is one steady state run (inertia does not matter) and one sweep. Then make the readings match at the steady state RPM by adjusting the MOI, which only will impact the sweep. The YourDyno software now has a special inertia measurement function that can automatically calculate the MOI. MOI vary a bit from car to car, so if you are after the most accurate engine readings then you should test the MOI for each car. Many dyno operators use a fixed or semi-fixed number for the MOI though.
Most dyno's DAQ can't measure race cars like rally or rallycross , due to the short gear ratio and small engine inertia ( 4 in line engine with light flywheel under 3 kgs and forged crankshaft for example) . Is your method able to measure it with results like a engine dyno ?
There are many ways to do it. Another way that works well is to do a slow power sweep and a fast power sweep, say for example 250 RPM/s and 600 RPM/s. The runs should overlay when the MOI is correct. This can be done with almost any engine. Make sure the boost overlays too and is not lagging on the fast sweep, otherwise you will get some difference even when the MOI is correct. YourDyno also has an MOI wizard that measures the retardation time with 0 brake and a little brake, and from there calculates the MOI. This works well if the dyno has enough MOI
