Quote:
Originally Posted by MazdaMatt
I must dissagree with the statement that a wheel weighing 40 pounds more can be simply compensated for with a stiffer shock. The car will absolutely handle adversely in comparison...
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you know me better than that... every vehicle will respond to lighter unsprung weight, particularly a sporty car
It looked to me as though you were saying you'd need to step up the carrying capacity and beefiness of the overall vehicle if you added weighty hub motors, if you added a bunch of unsprung weight.
I was trying to point out this fact; as unsprung weight goes up, <other than the shock> the car's suspension isn't working any harder. Said another way, fill your tires with concrete. The overall weight of the vehicle gows up, but the required spring is the same, the ride height stays the same. But yes, the car with concrete filled tires now handles like a pig, on that we certainly agree <although I've never tried riding a pig.. not on on ice anyway
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The job of the shock is to control the velocity of the wheel tire assy when a bump excites it. Not stop, but slow down at a controlled rate. Increase the unsprung weight, and the mass set into motion by that bump will still need to be controlled, thus, a heavier valved shock (to have similar control). Acceleration of the <now heavier> rotating mass is slowed somewhat, but you know, at eccomodder/hypermiler acceleration rates, I doubt you'd notice. The Pulson hub motor's mass looks close to axle centerline, making it much better than my 'concrete in the tires' example.
Going the other direction for a moment, one way to give the effect of a stiffer shock on a performance car is to just reduce unsprung weight. That is one reason there is such a performance and 'feel' difference on a sporty or race car when you put on a set of race-weight wheels. Acceleration feels quicker, as well. Lighter wheels don't change the rate or degree of body roll, or change the ride height, or have much effect on overall weight of the vehicle, however, the 'feel' difference is a result of an effectively stiffer shock and slightly quicker acceleration from the lighter wheels (a couple things you'd not notice or care about in most EV's) It's a tough concept to wrap you mind around, but it's real.