You need to know a lot more about the geometry of the car , and the braking deceleration (BRaking G's) is a function of other variables. I'lm ignoring aerodynamics in the following calcs - you need a lot of detailed info on downforce and drag if you want to include aero in your calcs.
1. Maximum braking deceleration = coefficient of friction between road and tyres multiplied by (weight of vehicle + downforce {if you know what it is}).
2. Find weight transfer under braking - you need to draw a free body diagram of all the forces acting on the vehicle, including the braking deceleration (F=M*A). If you do a moment balance about the rear contact patch it will give you the weight carried by the front axle.
3. Remember there are two wheels on the front axle so weight carried by each wheel is half of the axle load.
4. Torque to lock wheel = Coefficient of friction (tyre/road) * Weight on wheel * Tyre Radius.
If you want to find the rear brake torque then simply find the weight on an rear wheel and use it to obtain the wheel locking toorque.
Hope this helps - I can't find a scanner or I would give you the analysis with diagrams and a full derivation.
I forgot the mention some assumptions in my previous post - I assumed that the coefficient of friction was constant (reasonable for a first calculation).
Also that when you draw the forces acting on the vehicle, the "braking decceleration force" acts through the centre of mass and points forward for braking - iit's an application of D'Alemberts' Principle which is a little counterintuitive.
I was referring to the turning moment (torque) - force mulitplied by distance.
If you know the drag force then this is represented by a horizontal force acting backwards, at the height of the centre of pressure. If you don't have data to give you the centre of pressure then assume the centre of pressure to act at the same height as the centre of mass or halfway up the height of the vehicle, whichever is greater.
Say ReubenG:
On the whole I'm good with physics theory, but horrible with the math. I'm actually working on a MOD for a racing simulation game, Electronic Arts F1 Challenge 99-02. The MOD was released to the public through several sites already.
I had posted at other gaming sites for a physics person to assist me in releasing an update, but I've gotten no takers so far. I was wondering if you, or anyone else who reads this, is interested in doing some calculations for me it would be greatly appreciated by me and, I'm sure, the MOD community. The MOD is called Champ Car 2003. As far as I know there are six sites which are distributing the MOD. But... the physics needs work.
I have managed to get some good information from one of the very helpful teams of the series. But putting that info into a format the game can use is tough for me.
If your curious the type of calculations that need to be done are determining, reasonably well enough for the game simulation: inertias, torque forces, drag forces, tire data, and so on. I have roughly about 35 different variables to calculate yet. Some easier than other.
Mail me at reubengovender@gmail.com.
I can't promise whether I'll be able to help as I'm getting really busy with my M.Sc project but I have a little experience with vehicle dynamics calcs.
