Interesting video about a weird bug in a car speed limiter. It skips up and down by 2 mph, but when going down from 38 to 36, it skips 36 and goes to 34. The video includes some theories about...
Interesting video about a weird bug in a car speed limiter. It skips up and down by 2 mph, but when going down from 38 to 36, it skips 36 and goes to 34. The video includes some theories about what caused it.
Mod note: I wanted to de-editorialize the title, but I couldn’t come up with a better title. Please feel free to change the title.
I don't know if they mention this in the video but this immediately makes me think about something I read before in automatic cars: the stator clutch. I'm not 100% sure if it's specifically the...
it skips 36 and goes to 34
I don't know if they mention this in the video but this immediately makes me think about something I read before in automatic cars: the stator clutch.
As the vehicle accelerates, the turbine gradually gains speed in relation to the impeller. Eventually, the turbine speeds up to the point where the fluid begins to flow in one direction (clockwise).
As centrifugal force reduces vortex flow, torque multiplication is also reduced. Finally, when the turbine’s speed reaches about 90 percent of the impeller’s speed, the torque converter reaches “coupling” phase. In this phase, the torque converter simply transmits engine torque through the fluid coupling to the transmission input shaft.
I'm not 100% sure if it's specifically the torque converter where 36 mph would be inefficient to stay at but I imagine there could very well be a component of a car where they decided to just skip 36 mph to increase the efficiency or longevity of the mechanical parts of the car (perhaps even a resonant frequency?? lol) rather than a specific electronic programming mistake.
Interesting thought! I don’t know what the typical lockout point for torque converters is, but I think it’s around that speed depending on the car. As a side note, it has always surprised me how...
Interesting thought! I don’t know what the typical lockout point for torque converters is, but I think it’s around that speed depending on the car. As a side note, it has always surprised me how reliable fluid torque converters can be. It just feels like one of those things that should work in theory, but be unreliable in practice. Very cool technology!
However the big hole in your theory is that the big only happens in one direction. It will go 34 -> 36 -> 38 just fine, but goes 38 -> 34 on the way back down.
Interesting video about a weird bug in a car speed limiter. It skips up and down by 2 mph, but when going down from 38 to 36, it skips 36 and goes to 34. The video includes some theories about what caused it.
Mod note: I wanted to de-editorialize the title, but I couldn’t come up with a better title. Please feel free to change the title.
I don't know if they mention this in the video but this immediately makes me think about something I read before in automatic cars: the stator clutch.
I'm not 100% sure if it's specifically the torque converter where 36 mph would be inefficient to stay at but I imagine there could very well be a component of a car where they decided to just skip 36 mph to increase the efficiency or longevity of the mechanical parts of the car (perhaps even a resonant frequency?? lol) rather than a specific electronic programming mistake.
Interesting thought! I don’t know what the typical lockout point for torque converters is, but I think it’s around that speed depending on the car. As a side note, it has always surprised me how reliable fluid torque converters can be. It just feels like one of those things that should work in theory, but be unreliable in practice. Very cool technology!
However the big hole in your theory is that the big only happens in one direction. It will go 34 -> 36 -> 38 just fine, but goes 38 -> 34 on the way back down.