Rather, it appears fairly constant considering the exceptionally high acceleration observed at low speeds in my results.
I’m curious why such a difference has occurred…
I agree that the developers modeled clutch operation correctly in terms of output torque.
(Though not in engine rev, which should also be constant. But I think it was necessary to make engine sound more realistic.)
Yeah I am slightly amused by the fact that acceleration is about 80% of the max in 8th gear, when starting. I guess this is then modelling torque converters as they say.
I reviewed my old experiment results, and I came to believe that the developers had correctly modelled gear opearations and output characteristics.
What puzzles me now is the reason why they can’t introduce torque converters.
It seems very simple: just replace the current torque curve (orange) with the green curve.
Yes, now my next question would be, how do gas turbines and petrol engines perform in game. We should test how the curve shape differs, if at all.
Remember the converter is only used in 1st or 2nd gear, so you can’t just change the curve.
To better understand the differences between engine types, and the variations within each type, I think it would be helpful to gather torque curves across a wide range of engines, including those used in civilian applications.
Actually, I believe the torque converter is used in every gear.
For example, the 900-T transmission used in the M18 Hellcat and M26 Pershing, as well as the Allison CD-500-3 used in the M41 Walker Bulldog, operate this way.
According to the 900-T manual, traction force is greatest at 0 mph in all gears, which indicates that torque multiplication occurs in 2nd and 3rd gear as well: Detroit Transmission in World War Two - The Torqmatic Transmision 350-T
Similarly, the CD-500-3 manual describes “high range” and “high range lock-up” as separate operating conditions, implying that torque multiplication also happens in 2nd (high range) gear when it’s not locked up: TM 9-1730B Cross-Drive Transmission Models CD-500-3 and -4 (Allison-GM) : United States. Department of the Army : Free Download, Borrow, and Streaming : Internet Archive
Not in any modern vehicle it is not. I dont see why older vehicles would either.
yes it is common for both 1st and 2nd to not be locked up, since 1st gear isnt always actually used in a tank.
Indeed, both in game and comparitive real curves.
I didn’t know that — thanks for the correction!
I had imagined the lock-up clutch would engage whenever the converter output torque is (or is expected to be) lower than the input torque, regardless of the gear, as that seemed like it would give the best performance.
I think I should gather information on lock-up clutch operations along with other characteristics of historical torque converters too.
From an implementation standpoint, the torque characteristics can be just switched between with and without the converter, so torque multiplication can be limited to some gears if needed.
"mechanics": {
"steerType": "clutch_braking",
"maxBrakeForce": 60000.0,
"driveGearRadius": 0.385,
"mainGearRatio": 17.8,
"sideGearRatio": 0.958,
"baseTorqueType": "petrol_na",
"converterTorqueType": "petrol_na_900-T",
"gearRatios": {
"ratio": [
-0.756,
{ "ratio": -1.512, "torqueMultiplication": true },
0.0,
{ "ratio": 2.0, "torqueMultiplication": true },
{ "ratio": 1.0, "torqueMultiplication": true},
0.739,
0.477,
0.361,
0.244
]
}
},
This example uses a naturally aspirated petrol engine and a 900-T torque converter. The torque curve with the converter is assumed to be pre-calculated, but how it’s defined is up to the devs.
Instead of “torque converter type” you could specify the multiplier, since the “curve” for each converter is practically identical with a different gradient depending on the multiplier.