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Re: accelerating while cornering

To: triumphs@Autox.Team.Net
Subject: Re: accelerating while cornering
From: smith007@mindspring.com (Phil Smith)
Date: Thu, 26 Feb 1998 08:53:45 -0500
>Ah, seems to be the evening to spout off about anything but
>Triumphs.  Maybe 'cause my *&!%! parts aren't here yet....
>
>The simple answer is that accelerating while in a curve helps
>the car negotiate the curve by moving the car towards understeer
>(in a manner of speaking.)  Braking while in a curve moves the car
>towards oversteer.  So you should slow down before entering the
>curve, then accelerate through the curve (but not 'till the back
>wheels come loose :-)
>
>If you want the long answer keep reading.  I've tried to interpret
>the math in useful terms.  Please don't let the following paragraph
>stop you.
>
>Vector analysis of the motion of a particle along a curve
>results in the following expression for the acceleration
>vector A acting on the particle:
>
>A = (s' )T + (s^2 K) N,
>
>where
>
>s' is the rate of change in the speed of the particle
>T is the unit tangent vector
>s^2 is the square of the speed
>K is the curvature
>N is the unit normal vector
>
>These two vectors, (s')T and (s^2 K) N, add together to get the
>acceleration acting on the car.
>
>Assume for the sake of example that you're turning
>left, like at Indy (I can dream can't I).  Since N always points
>towards the center  of curvature, it points directly left over
>the driver's door.  T always points straight ahead over the hood.
>If s' is positive (goosing the gas) then A points toward where you
>want to be (ahead and to the left.)  When s' is negative (braking),
>A points behind and to the left, where you were, not where you want
>to go.  A picture in this case would be worth most of the preceding
>457 words.
>
>See, 15 years of math and a PhD is useful for something besides
>adding up the cost of all those parts.
>
>
>At 10:49 AM 02/26/98 +1100, you wrote:
>>
>>Rich,
>>
>>At 11:53 25/02/98 +0000, you wrote:
>>>I always understood it that it was best to keep your boot down when going
>round
>>>a corner so that you got the negative camber of the rear wheels, this
>will give
>>>you better grip, because as the body rolls, the outside wheel will become
>more
>>>upright, if you think about it, if the wheels are upright to start with,
>then
>>>they tilt over a bit, then you are getting similiarites to positive camber.
>>
>>The centripetal force (between the road and the tire) is responsible for the
>>camber change. One reason for accelerating is that doing so transfers weight
>>from the front to the rear wheels, improving their grip. There may also be
>>2nd-order effects I haven't read about. Someday I'll have to get out my
>>Classical Mechanics textbooks and suspension books, install Mathematica on
>>my PC, and produce the definitive treatise.
>>
>>Allen Nugent
>>Graduate School of Biomedical Engineering
>>University of New South Wales
>>Sydney  2052  Australia
>>
>>
>Cliff Hansen
>chansen@exis.net
>1966 TR-4A  CTC 64615L (Hibernating for front end work)

Gohlee Shazam that's some kinda siffer'n !!


 Phil Smith
   69 TR6
  " More Dreams than money "






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