What are your ramp test settings?
Just to be sure, are you putting the gearbox in neutral for coastdown?
hi
no i just pres the clutch and coast down in the gear that i used for the ramp test.
thats the way i do it on my roller dyno
i will try to shift to neutral to see if it makes a difference?
thanks for your patience with my questions
now i have tried shifting to neutral on coastdown. it is the same result!
but if i make a run in sequence test, where i make the sequencer hold the top speed
and then coast with the clutch depressed, the brake controller goes to zero and stayes the during the entire coast down phase.
and then the losses seems to be more normal
Neutral or clutch should be similar. What I had in mind when asking the question is if you haven't been doing coastdown in gear.
Anyway the losses I see in your screenshots are quite high for the hub dyno. Maybe the moment of inertia for the hubs (rollers) are set higher than they are in reality?
ok
i think the inertia values is quite ok, when i do a double ramp the curve up and down is very close.
i think the problem is that the brakes is activated during coast down- but that only happens when i do the ramp test when i make a run in sequenser mode the barkes dont turn on during coast down.
here i attach picture of 2 runs
one in ramp test and one in sequencer
is there a setting ghat turns brakes of during coast down when in ramp test
If you use "costdown rate" it will force faster deceleration during coastdown. In theory you have all the power measurement settings dialed in correctly, then it won't affect the losses measurement. In practice, reasonable deceleration rates do not affect losses, and if you go for some extremely fast deceleration it will affect losses. That's especially true for roller dynos.
ok.
i cant turn of the brake during deceleration in ramp test mode!
the brake stays on like in the pictures attached above
there is no difference if i set different decel rates or if i set the coastdown rate to on or off
it seems that the ramp test dont work like it should
maybe i can try downloading an other version of the dyno program to see if that makes a difference
i have tried downloading the stable version
it made no difference
so for now i cant use the ramp test
