Comments by "geemy" (@geemy9675) on "Toyota GR Corolla's Brilliant AWD System - How It Splits Torque!" video.

  1. so if you're driving on cruise control at 80mph on the highway, wheel rpm is about 1000rpm, so the shaft is about 4000 rpm so the clutch will slip at around 4000*0.7%~30rpm and at low load, but it doesn't make sense that the clutch doesn't completely disengage, to reduce wear and fuel consumption? obviously mileage os not concern #1 on a corolla GR, but reliability under heavy use? I understand it's not going to heat up or wear as fast as a clutch launching the car at 3000+ rpm but still a very odd design to have a clutch slipping 100% of the time. plus a manual transmission only has a big speed difference when starting from a dead stop, when changing gear, speed difference is either minimal (perfect shift) or the clutch slips and the engine speed matches the gearbox after a few tenths of a second. the clutch spends less than 0.7% of the time slipping from a stop to first gear, and it has thermal mass to take the heat, and then cool down when its not used, whereas this will lose power and generate heat continuously. If you hammer a clutch several time in short intervals its going to overheat for sure. my concern is not only that there's a clutch slipping all the time, but that its also responsible for continuously transferring ~50% of the torque to the rear wheels so not. Of course if it makes the AWD/handling better, the part is easily serviceable, then OK why not! people who are lucky enough to put their hands on this car wont mind low mpg
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  2. I'm just thinking that having 4wheel steering with equal (opposite) angles would be the only way to always match front and rear wheels speeds and could simplify the design of a track oriented AWD. I know most rear wheel steering use variable ratios depnding on the speed or even switch the angle at different speeds, but could a "simple" system just mirroring the front be actually simpler ? it would mean also it would need wheel arches and suspension that can accomodate the same full lock steering as the front. but it would have ways smaller turning radius, or you could also halve the angles and make it easier/simpler/cheaper. has it been tried already (other that on monster trucks/rock crawlers)
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