Home Forums General Karting Discussion does more weight equal more corner grip?

This topic contains 9 replies, has 6 voices, and was last updated by  TJ Koyen 4 years, 7 months ago.

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  • #37414

    michael smith
    Participant

    Hi, so I know that acceleration and braking are worse with weight but how about cornering?

    I know that open wheel racing, downforce is a big deal, so is extra weight in a Kart achieving the same result?

  • #37417

    tony zambos
    Participant

    As two famous radio show hosts would preface some of their answers by claiming the answer was arrived at without the encumbrance of the thought process, I too will apply that statement to my answer.

    The short answer is no. The aerodynamics of an open wheel vehicle provides additional down force, trying to overcome the car’s forward inertia that is trying to keep the car going straight. The heavier a kart is, the more forward inertia it has as it tries to turn.

    And don’t drive like my brother.

    LAD Specialties customer / tony kart / rotax / kt100

  • #37430

    TJ Koyen
    Moderator

    Cornering is also worse with weight. Weight is always the enemy, never your friend.

    Driver/Coach/Wrench : Innovative Performance/Exprit
    Owner : Oktane Visual - www.oktanevisual.com
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  • #37432

    michael smith
    Participant

    ok, guys can you please break it down for me. i know weight is is generally bad, but i would like to know the science of how more weight equals less cornering grip.

    reason im confused on this is that formula 1 cars, for example, usually add wing and downforce to aid in cornering force, which is essentially equal to weight but without the braking and acceleration penalty of weight in the car.

    break this down for me scientifically please.

  • #37433

    Jim Derrig
    Participant

    More weight does not mean less grip.  It means more grip, but the additional grip is not enough to overcome the additional inertia created by the extra weight.

    Aerodynamic downforce does not create additional inertia, so it is “free” additional grip from that point of view.  With aero the penalty is drag, not inertia

    Don’t feel bad about the confusion.  For decades this was seriously debated in racing circles, with some contending that more weight helped the car “hug the road” better.  The debate ended around the late 1950’s, with Colin Chapman repeatedly beat heavier, higher powered cars with his lightweight designs.

  • #37437

    michael smith
    Participant

    thanks . I actually found a great description in herb adams book chassis engineering. chapter 1 ,lol deals with this. basically, cornering force increases with vertical load, but not as fast as vertical load.

    so . if 500lbs of vertical load is 700lbs of traction then cornering efficiency is 700/500or 1.4

    if load increases to 1000lbs and traction increases to 1000lbs then cornering efficiency is lowered to 1.0 even though traction did increase.(1000/1000)

    finally, say you increase vertical load to 1500lbs but traction only increases to 1250 then you have again increased traction but decreased cornering efficiency
    1250/1500 or .83

    thanks all

  • #37441

    FREDDY SANDOVAL
    Participant

    Michael
    When you see a F1 car, or an Indy car the front wing being adjusted for more down force at the front, it normally helps you to corner a lot better by creating more weigh to the front wheels for road courses, and some rather smaller tracks, but this is a different kind of weight.
    This weight is applied directly to the front wheels, body and suspension created by aerodynamic down force, that will eventually affect the steering axis tilt.

    In karting it is a totally different animal, as you can’t ad weights to each wheel or each corner of each axle, you can only place weights to certain spots of your seat, floor pan and chassis, Plus the behavior of a kart chassis and its flexibility is by far unlike a race car, as there is no suspension, yes the chassis flexes in a way as if they did have suspension, but they don’t.

    So that being said, they do not rely on upper and lower control arms (wish bone suspension), both front and rear, with ball joints that helps keep the steering hubs/knucles and tires in place, as the vehicle travels up and down. Go karts flex up and down in a way, but do not travel freely since there’s drag at the bottom of the tires, so we’re constantly pushing on the rubber, then eventually the kart slides, glides and rotates.

    I would love to ask you what it is that you’re trying to achieve? So that we may understand a little better, and decide where to go with your question.
    Unfortunately I am not a scientific, but we can give it our best shot in trying to help you. But I am really curious to know what your plans are, that way we can share the geometry and the physics of race cars and race karts.

  • #37446

    Walt Gifford
    Participant

    Newton’s first law of motion is working against you.

    FAA certified jet engine and aircraft technician,
    Nicholson Speedway class champion 2001,
    Yamaha KT100 Service Center,
    41 years karting experience

  • #37449

    michael smith
    Participant

    According to Newton’s first law…

    An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force.This law is often called “the law of inertia.

    Can you expound on how this affects cornering force?

  • #37451

    TJ Koyen
    Moderator

    An object with more mass requires more force for it to change direction or speed.

    Heavier kart requires more force for it to turn a corner. Jim explained this a few posts up.

    Driver/Coach/Wrench : Innovative Performance/Exprit
    Owner : Oktane Visual - www.oktanevisual.com
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