Hi,
Trying to figure out proper engine importing in your engine PiBoSo. I am however dumbfounded by this value:
engine
{
Inertia = 0.005
What is it? Where does it come from? I'm hoping to understand why you have the values you are using, which are:
250f: 0.004
350f: 0.005
450f: 0.005 (? same as 350?)
250: 0.005 (a 2 strokes with more inertia than 4 stroke of same cc?)
Both models that have ? are marked as WIP in the bikes page though.
I'm running a few tests right now, but not sure what I should be looking for nor where I should start from. Any help appreciated.
I'm not smart enough to figure out which discussion on the PiBoSo board is relevent, but there are a few interesting / hopefull looking bits of information on there if you search for 'inertia'..
Tried that. There is a lot about weight inertia (mass of the chassis etc) but barely anything on engine inertia. Which seems to have a massive influence on how a bike revs up and revs down by itself.
I have a "perfect" .engn file of a 125 2s along with perfect gear ratios etc. I happen to have more or less the same bike IRL. An engine with inertia of 0.004 feels like a blocked air filter, 0.003 feels like a well set up 125 engine.
Then again I could be talking out of my ass and seeing things I want to see, since I have no idea what the number represents or comes from.
If I remember good that inertia makes engine to raise rpm easier or harder.
Good way to gauge your inertia value:
Stay in neutral. Hit the rev limiter. Time how long it takes to decay to idle rpm. Compare to youtube video of an idiot doing that on a real bike.
0.005 seems good for a 450. 0.004 a tad high for a 250F, I'd say 0.0035 would be closer but it's tough to say.
Quote from: Asdrael on February 05, 2017, 07:50:07 PM
Good way to gauge your inertia value:
Stay in neutral. Hit the rev limiter. Time how long it takes to decay to idle rpm. Compare to youtube video of an idiot doing that on a real bike.
Hmmm ... that would be affected by the braking torque too, not only by inertia no ?
Quote from: HornetMaX on February 06, 2017, 06:52:44 PM
Hmmm ... that would be affected by the braking torque too, not only by inertia no ?
tbh I can't really say. I will stick to default values (except 125 2 stroke for which 0.003 is a good value) until I figure out how this works. I suppose brake torque affects it slightly, but I was under the impression brake torque was affecting more the resistance of the engine to external forces, not its own.
Then again might be talking out of my poophole.
Hmm .. I'm not sure either on this one ...thinking ...
After quite a lot of experimenting, I am settling for this when doing "custom replica" engines.
Inertia:
- 125 at 0.003
- 250 at 0.004
- 250f at 0.004
- 450f at 0.006
Engine breaking torque:
- stock 250 and 250f
- 125 adapted / rescaled from 250
- 450f adapted / rescaled from 250f
At least that's what I am using in my latest "OEM" stuff and so far the feedback has been good but sparse :P