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Automotive Can you give any ideas about brake torque produced by car

  1. Apr 10, 2012 #1
    I m doing ABS simulation, now I just wonder that how much break torque that brake pressure can produce,,, in my simulation I used about 1000 NM, I dont know is it too much?
    However, the result shown that car will stop from 180km/hr in abt 5 s,,,Is it make sense?

    Between, in the my code, I didnt input the limited of working of brake hydraulic.
  2. jcsd
  3. Apr 11, 2012 #2
    Braking distance (&time) is typically limited by your coefficient of STATIC friction between the tires & the road. The brakes are capable of generating more frictional force than the tires, resulting in the wheels locking up. Locked tires then SLIDE down the road, resulting in less friction.

    ABS reduces the breaking pressure to slightly below that required to lock the wheels (pressure fluctuates, not constant), ensuring the wheels keep turning & you can steer the car.

    If checking your simulation for 'reasonable' results, choose a test vehicle, get the basic product information (mass, braking distance), back-calculate the coefficient of friction for the tires, and use that as your limit.

    10x braking force does not equal 10x faster braking :(
  4. Apr 13, 2012 #3
    Such a vague question really, but I figure that my 2750lb car can deploy a maximum of 2200lbs of brake force to the road on high performance road tyres, with around 75lbs of pedal force. This is good to go from 180kmh to 0 in 6.3 seconds.
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