Yeah the amount of BS or confidently incorrect in tech articles about automotive engineering is crazy.
And while gear-sets are really efficient, adding 8 to each of the 4 wheels 32 total, in leu of 2-4 at each end of the car, plus 4 CVs (assuming it’s AWD) has to be close in efficiency. And as a DIY+ car restorer in New England. I wanna see how they seal this thing. And with steering wheels it’s either gonna have to swing the motor around or put the CV back in anyway.
NVH (noise vibration harshness) is also going to be a huge factor. That and cost and weight is why we don’t have gear driven camshafts except on a select few exotic motorcycle engines and F1 engines.
Helical gears are the cost effective way to reduce gear noise, but they impart axial loads which would be difficult to overcome in this hinged joint. Herringbone fears eliminate the axial load, but are much harder to make, unless you go with powdered metal sintering. Which I barely trust in a cordless drill, let alone a Kia.
Edit: And no accounting for wheel castor, or camber changes along the suspension travel (way more basic and important for handling than torque vectoring). This video is pure marketing wank.
Funny you mention motorcycles with gear-driven cams as being exotic. Generally correct, but I happen to own one of the cheapest out there: the Honda VFR. I sought out mine for being the last with the gears before going to a normal drive in 02. It’s a glorious sound.
Anyway, that’s true too, helical gear will need a beefy housing to resist that axial load. That’s more weight. A pair of helicals fastened together could help bring down cost, probably, compared to herringbone, but that’s added complexity. I can’t claim the tech is marketing wank but the video absolutely is
Yeah the amount of BS or confidently incorrect in tech articles about automotive engineering is crazy.
And while gear-sets are really efficient, adding 8 to each of the 4 wheels 32 total, in leu of 2-4 at each end of the car, plus 4 CVs (assuming it’s AWD) has to be close in efficiency. And as a DIY+ car restorer in New England. I wanna see how they seal this thing. And with steering wheels it’s either gonna have to swing the motor around or put the CV back in anyway.
NVH (noise vibration harshness) is also going to be a huge factor. That and cost and weight is why we don’t have gear driven camshafts except on a select few exotic motorcycle engines and F1 engines.
Helical gears are the cost effective way to reduce gear noise, but they impart axial loads which would be difficult to overcome in this hinged joint. Herringbone fears eliminate the axial load, but are much harder to make, unless you go with powdered metal sintering. Which I barely trust in a cordless drill, let alone a Kia.
Edit: And no accounting for wheel castor, or camber changes along the suspension travel (way more basic and important for handling than torque vectoring). This video is pure marketing wank.
Funny you mention motorcycles with gear-driven cams as being exotic. Generally correct, but I happen to own one of the cheapest out there: the Honda VFR. I sought out mine for being the last with the gears before going to a normal drive in 02. It’s a glorious sound.
Anyway, that’s true too, helical gear will need a beefy housing to resist that axial load. That’s more weight. A pair of helicals fastened together could help bring down cost, probably, compared to herringbone, but that’s added complexity. I can’t claim the tech is marketing wank but the video absolutely is