GregLocock
Automotive
"Up to" 25% more grip eh? Hmm. Pacejka time.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
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Active Toe and Camber prototype
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"Up to" 25% more grip eh? Hmm. Pacejka time.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
BrianPetersen
Mechanical
Interesting.
I wonder if this could be used to make a stone-axe-simple suspension design behave, instead of having 5 links plus a hub carrier per side, to offset some of the cost. Doubt if Lamborghini would do that, though.
I wonder if this could be used to make a stone-axe-simple suspension design behave, instead of having 5 links plus a hub carrier per side, to offset some of the cost. Doubt if Lamborghini would do that, though.
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GregLocock
Automotive
Live rear axle plus active toe and camber for the off road guys. Or as one old guy recommended, De Dion twistbeam, but with active toe and camber for on road. Or my preferred option, reverse twistbeam with small wheel motors and active toe and camber for BEVs.
Definitely fun for the development engineers. So many toys, so little time.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
Definitely fun for the development engineers. So many toys, so little time.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
cibachrome
Automotive
Active Toe can get you the Dynamic Toe (Ackermann + static toe) needed to get the best Fy from the PAIR of tires on the axle, and Active Camber can get you the minimum tire Mx, also for the best grip from a single tire. But Mu is still Mu.
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GregLocock
Automotive
Do you think most of the gain will be from roll/camber compensation, ie keeping the cP flat? I'm on the wrong computer, as usual.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
cibachrome
Automotive
Not sure because some types of tires have the 'snap-thru' problem: Mx can be held close to zero, but then it leaps to it's conventional preference. Can make a LOUD BANG on a tire test machine ! So this drastic change in roll moment can cause a rollover in SUVs. I have a video that shows a Saturn View breaking a rear control arm because of it.
Next, with +-6 deg of camber change, the wheelhouse has to be made larger to fit the new steer & camber displacements. Friendly rub ? I don't want anything rubbing my sidewalls. I suppose you'd want to go back to bias belted tires in order to make the camber thrust worthwhile. Maybe on race tires because their 'racing radials' are actually bias ply sidewalls. Just burn one in a fire pit to see how they look without the camo rubber.
So, toe is the only dynamic d.o.f. I'd vote for. Only need ONE actuator (ignore the offset steering wheel spokes). Tire wear, maybe some fuel economy because of residual forces & moments, squeal in the parking garage, and a few extra decimals at max lat if you vote for anti-Ackermann. RW steering made the most sense to me for response time reduction and turn circle, especially for pickup trucks pulling bumper hitch trailers whose owners could not afford the better gooseneck hitch option. But GM couldn't give it away. Plus the Safety Jihadis forbid using more than a few degrees of toe change, when the real advantage came when 3 - 4 times that made it awesome.
What do you think about steer by wire and steer augmentation via 4 wheel traction motors ? Tire wear, durability, cost, parts inventory, and Crash Safety are the winners here (IMHO). We put hundreds of peeps way up in the air with SBW controls on a plane that has a few extra degrees of freedom to manage and nobody kicks the tires. You mostly never hurt people in a plane crash. Killing them seems like the least costly option.
Next, with +-6 deg of camber change, the wheelhouse has to be made larger to fit the new steer & camber displacements. Friendly rub ? I don't want anything rubbing my sidewalls. I suppose you'd want to go back to bias belted tires in order to make the camber thrust worthwhile. Maybe on race tires because their 'racing radials' are actually bias ply sidewalls. Just burn one in a fire pit to see how they look without the camo rubber.
So, toe is the only dynamic d.o.f. I'd vote for. Only need ONE actuator (ignore the offset steering wheel spokes). Tire wear, maybe some fuel economy because of residual forces & moments, squeal in the parking garage, and a few extra decimals at max lat if you vote for anti-Ackermann. RW steering made the most sense to me for response time reduction and turn circle, especially for pickup trucks pulling bumper hitch trailers whose owners could not afford the better gooseneck hitch option. But GM couldn't give it away. Plus the Safety Jihadis forbid using more than a few degrees of toe change, when the real advantage came when 3 - 4 times that made it awesome.
What do you think about steer by wire and steer augmentation via 4 wheel traction motors ? Tire wear, durability, cost, parts inventory, and Crash Safety are the winners here (IMHO). We put hundreds of peeps way up in the air with SBW controls on a plane that has a few extra degrees of freedom to manage and nobody kicks the tires. You mostly never hurt people in a plane crash. Killing them seems like the least costly option.
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