Do rear locking/limited slip diffs increase or decrease oversteer? What about on the front axle? What do they actually do to the driving dynamics?
>>28120443A car without a mechanical LSD is just a novelty car
>>28120443Its a mix bag.Locking left and right wheel to the same speed or limit to be closer is obviously creates understeer by thrust vectoring, Because during a turn, outside track is longer than inside, thus outside wheel should move faster than inside. By locking, it forces outside to roll slower, acting as braking on the outside, and forces inside wheel to roll faster, acting as inside gas, there for making the vehicle go straight.However other factors has to be considered.First is geometry, that most vehicle other than kart is longer than it is wide, this aspect ratio means the lateral(sideway) grip of the front and back wheels is usually more important than thrust difference on the left and right wheels thrust forward or backward. Adjusting the front or back anti-roll bar is thus the most effective factor in balance. Oversteering is caused by the front grips much better than the rear, thus tougher front anti-roll or softer rear would make stable as wheels more evenly loaded gets more grip overall.Second is this mechanism rely on the fact both wheel can provide equal grip given by equal normal force(downforce), but there are weight transfer on the front and back, as well as left and right. The amount of weight transfer depends on the center of mass, the height and distances to the wheels. The lock diff's correction effect is weakened if weight is transferred to the other two wheels, or inside tire slips or lifts up that no longer slow the outside wheel down.Third is that a tire has limited traction circle, that the amount of lateral and tangential grip has to trade off before both suffers. By adding tangential thrust, it would lower the amount of lateral forces than open(unlocked) wheels, subsequently upsets the front and back balance.
slip is the difference in speed between the left and right wheel on an axle.a limited slip diff prevents one wheel from going faster than the other.this improves handling by making it so the wheels on an axle are linked together, but not locked together.most cars have an open diff, which allows both wheels to spin independently. this is fine normally but in hard cornering or uneven terrain, if one of the drive wheels comes off the ground or loses grip, all the power of the engine will take the path of least resistance and spin only that wheel instead of both at once. this leads to bad and unpredictable handling as well as unreliable performance offroad. a limited slip diff solves this problem.
>>28120753>>28120755based info dumperquestions:if i had an AWD car with an LSD on both ends, would increasing the preload on either diff increase mechanical understeer?Would increasing the rear preload increase power oversteer?Would increasing front preload increase power understeer?
>>28121087On an AWD car usually the front diff is not limited slip because you actually want your turning wheels to be able to rotate independently most of the time. If you link the front wheels together and they don't have enough slip allowed you will get understeer and massive tire wear.I'm not sure preload alone will make the car understeer, it really depends greatly on the accel/decel locking percentage, the preload is simply how fast it responds to accelerating or decelerating. with fwd cars usually a great deal of slip is allowed on accel, and less on decel so that the cars can be "tossed" into corners stably and track themselves straight without a lot of input from the driver. An open diff fwd car can easily get itself into an unrecoverable spin, the diff equipped car can get itself out of a spin with throttle and steering.so to answer your question, yes. both. By increasing the preload you are changing the speed at which the diff changes states, making it slower to go from accel to decel, which may not be desirable and cause understeer.
>>28120737God I wish that was my car
>>28120737kek enjoy the audisteer
>>28120443The only cars that matter are rwd with lsd. Awd is a meme for anything on a road and everything with an open diff does 1 wheel peels exiting turns on throttle. E-lsd electronic setups are a cope and make cars unusable when you turn traction control off and actually try to drive instead of having a computer do it for you (which will always intervene before the limit and cut power outside of some motorsports TCS unit in a gt3 car you will never drive)
