In search of tips on Vehicle handling tuning

hi there, i worked a lot lately on my racing game and as i modeled different drivetrains as FF,FR,4WD, i noticed that the FWD cars were better than the RWD and mostly equivalent to the 4WD (wich have tendency to oversteer), for small, low powered car that could be right but for a front massive FWD it should not, i adjusted the center of mass, i implemented a simple differential i found on the web (wich at lower than 50 km/h prevents the car from spinning out, and at above, helps for stability):
double tqright=tqinput;
double tqleft=tqinput;
double iFactor=10.0;
double omega_left,omega_right;

if(m_Direction>Ogre::Degree(0.05))//tournes a droite
{
tqright*=(1.0-(m_Direction.valueDegrees()/iFactor));
if(tqright<0)
tqright=0;
}
else if(m_Direction<-Ogre::Degree(0.05))// sinon tournes à gauche
{
tqleft*=(1.0-(m_Direction.valueDegrees()/iFactor));
if(tqleft<0)
tqleft=0;
}

I noticed that on FR cars (RWD) the front wheels when turned a lot seems to slow down the car(i hacked this by putting some torque on the front wheels but, i dont like that..) and also, contrarily to the FWD the car does'nt oversteer, drift, as easily (very surprising in fact..)

FWDs have a big tendency to spin out at high speed when steered too hard(calmed that with non linear steering)

4WDs are fun to drive as they "drift" easily and they lunch well (power proportion affect this), no real strange behavior here.

In all cases 4 wheel steering helps in having a car that does not oversteer or understeer

Have you noticed similar effects or other matter of interest conscerning a SimpeVehicle derived system?

I also noticed how usefull it was to play with the moment of inertia on the body of the car, as off now it was the most significant adjustment I made concerning stabiliti at high speed.

I noticed the same things on Stunt Playground, although the driving in that game was not a serious vehicle simulation, so I just tweaked the values until I got something that "felt right".

what i believe is that using the function to calculate the moment of inertia of a box is a start but it does not suffice to make the car feel like an MR,RR of FR car, as the inertia of the chassis greatly differ ,according to the positiion of the engine in the chassis, MR cars tend to have lower chassis inertia tha those with an engine far from the center of the car.

Also I have builded a first version of my game "Omnijobbeur Racing" ,
Still not perfect but it's a start.

here it is : http://omnijobbeur.no-ip.org
(available from 8hAM to 12 PM GST-5hours (..well not sure about GST) )
it installs the vc_redist_x86-sp1.exe patch
and OPenAl

Can support joystick input

4 cars available, (not a simulation but more an approxiamtion)
toyota celica 88 GT
toyota celica TA27
chevrolet camaro +-1996
plymouth cuda

1 track
daytona usa ,found on turbosquid

follow the instructions in the installation folder.

If you encounter bugs , notice me at jfrancoisbreton at hotmail.com