What is the ideal MR Driving Style?

Re:What is the ideal MR Driving Style? (Trav)

Fri, 02 Nov 2012 20:21:52 GMT

TRD2000

ummm what's a coefficient of "grip"?

grip = force (downward load or weight) X the coefficient of friction

the coeff of friction is determined by the chemical composition of your tires and their heat.... and the surface you're on.

the grip doesn't drop off with load... the braking load gets higher and overcomes the grip.

Sorry to cause any confusion, by coefficient of grip I was referring to the coefficient of friction. It is not constant as many believe.

If anyone is ever interested in car dynamics, I highly recommend reading Tune to Win - Carroll Smith, and Drive to Win also provides an insight to this area and gives much information on race car driving.

Re:What is the ideal MR Driving Style? (Engineering_guy)

Fri, 02 Nov 2012 20:16:45 GMT

I am also a huge fan of rfactor.
who would be interested in setting up a friendly comp?

Re:What is the ideal MR Driving Style? (Engineering_guy)

Fri, 02 Nov 2012 19:50:49 GMT

Trav is correct, but i didnt want to go into it that far in detail due to the risk of losing everyone.

It is true that the relationship between the normal force N (which is the force reacting to the weight of the car) and the force created F is not linear. It the increase of force per increase of weight lessens with greater and greater weight.
If this was not so a heavy car would be able to travel a corner as fast as a car that weighs nothing.

I was looking for a graph to show this, but google failed me.
Any other vehicle dynamics questions feel free to ask me.

Re:What is the ideal MR Driving Style? (TRD2000)

Fri, 02 Nov 2012 19:10:32 GMT

?? who

Re:What is the ideal MR Driving Style? (EssDub)

Fri, 02 Nov 2012 19:01:23 GMT

MUST.... RACE.... YOU.

rFactor is the ****. I roll the MR2 mod from F1Elites and the Project D 2.3.

Challenge?

Re:What is the ideal MR Driving Style? (TRD2000)

Fri, 02 Nov 2012 18:41:32 GMT

ummm what's a coefficient of "grip"?

grip = force (downward load or weight) X the coefficient of friction

the coeff of friction is determined by the chemical composition of your tires and their heat.... and the surface you're on.

the grip doesn't drop off with load... the braking load gets higher and overcomes the grip.

Re:What is the ideal MR Driving Style? (Trav)

Fri, 02 Nov 2012 17:40:39 GMT

Just to correct you slightly, the tyre coefficient of grip drops off slightly with increasing load which is the reason why weight transfer is a bad thing. This means that with more weight on the rear, there will be less of a drop in coefficient and you will have a slightly better potential for braking. This is provided that you have the optimal brake bias. Therefore a mid engine car should theoretically be ably to brake slightly harder than a front weight biased car with less of a drop in coefficient of grip (μ) and the sum of the total forces would be higher.

Re:What is the ideal MR Driving Style? (Tree)

Wed, 31 Oct 2012 21:17:40 GMT

Same thing applies to F1s I guess?
Yeh screw renewable energy! Nuclear Fuuuuusion all the way!! You should be helping to build the ITER! " />

Re:What is the ideal MR Driving Style? (Engineering_guy)

Wed, 31 Oct 2012 18:15:37 GMT

Glad I could be a source of entertainment/ confusion

Re:What is the ideal MR Driving Style? (MR PLOW)

Wed, 31 Oct 2012 18:10:25 GMT

You lost me after fun!

Re:What is the ideal MR Driving Style? (Knightrous)

Wed, 31 Oct 2012 18:01:36 GMT

Love the maths mate!

Re:What is the ideal MR Driving Style? (Engineering_guy)

Wed, 31 Oct 2012 17:56:02 GMT

Firstly in regards to braking:
The amount of force provided by the contact between 2 surfaces is given by:
F = uN (fun) where N is the force reacting to the contact (newtons 3rd law) and u is the coefficient of friction (this depends on surface type and tyre compound/temp)

Lets do an example. say we have 2 cars, both way 1000kgs, one experiences 85% of the total weight under heavy braking on the front wheels, the other 65%.
We will take u to be 1.2 (average coefficient for a road tyre just before slip).
And gravity to be 10 m/s2 (because im lazy lol, real figure is 9.81)
Mass x acceleration due to gravity = Normal force (N) x u = force due to friction
car 1: 85% of 1000kg is 850kg 850kg X 10m/s2 = 8500N x 1.2 = 10200N
Which means the rear of the car is experiencing,
15% of 1000 is 150 150 x 10 = 1500 x 1.2 = 1800N
Total Force = 12000N
Big difference
car 2 : 65% of 1000kg is 650kg 650kg x 10m/s2 = 6500N x 1.2 = 7800 N
and the rear = 4200 N
Total force = 12000N
Now what this shows is that on the FF car there is a lot more force put on the front wheels, which means an increase in the amount of braking force that can be applied.
This however does not meant that it can have more braking force applied overall.

This is why FF/FR cars have big front brakes and smaller rears, to take advantage of the weight shift.
But in the MR2 the brakes will be much more evenly sized.
In summary: Weight distrubution does not affect the total braking performance overall, but it does change the way the system must be designed.

Hope I havn't bored you all to death. But this was a great distraction from study for stupid renewable energy systems, bleh.

Re:What is the ideal MR Driving Style? (bigh)

Fri, 04 May 2012 07:02:29 GMT

thanks for the tips guys :)

Re:What is the ideal MR Driving Style? (Highlander)

Thu, 03 May 2012 21:23:54 GMT

Senol

I use Rfactor with the sw20 mod + g25 and you can download lakeside park, morgan park and even queensland raceway. Probably others, but ive downloaded those because they are my "local" tracks.

Where is the SW20 mod available please

Re:What is the ideal MR Driving Style? (Tree)

Thu, 03 May 2012 01:13:21 GMT

^Nice that sounds like a good idea for training local stuff
Atm I have GT5 + G27 and basically mastered the NA MR2 in the dry, wet takes more effort. F1 is a real challenge, my best times at Trial Mountain is low 1:03, mate got 1:02 and someone on youtube got 1:01 or 1:00. Using Gran Turismo Formula