Tune your custom car's performance
Once you've successfully built a custom car model and have it working in Midtown Madness, you can
tweak the car's performance characteristics to create a truly unique vehicle.
To tune your custom car model's performance characteristics, you make changes to the values stored
in the vp*.mmcarsim file (located in c:\vck\shop\tune ). As you tweak your car's setup, keep in mind
that certain tuning values and combinations of tuning values may cause your custom vehicle (or the
game) to behave erratically or stop responding (for example, assigning a negative mass value will
cause problems).
The Top 16 tuning parameters you can change in vp*.mmcarsim include the following:
- Mass. The Mass value is used to govern how the car's horsepower affects acceleration. It is
also used to resolve the effects of collisions. An object with greater mass will sustain less
damage when colliding with objects with lower mass.
- DrivetrainType. A value of 0 (zero) specifies a rear-wheel drive vehicle. A value of 1 (one)
specifies a front-wheel drive vehicle.
- MaxHorsePower. This value defines how much power a vehicle has. It largely relates to
top speed, but, in conjunction with gear ratios, it affects acceleration.
- NumGears. This value defines the number of gears your vehicle has. The maximum value
you can enter is 8; this includes neutral and reverse. This leaves a maximum of six available
forward gears, not all of which must be used.
- Spring, Damping, RubberSpring, RubberDamp, RubberSpringLat, and
RubberDampLat affect the suspension and ride characteristics of the vehicle.
- StaticFric (not StaticFriction). This value determines the general grip of the vehicle.
- GearRatios. Tuning these values in conjunction with the RPM values, is perhaps the most
challenging of all the tuning tasks. Combined with MaxHorsePower, the ratios determine the
acceleration and top speed capabilities of the car.
- OptRPM, MaxRPM, UpshiftRPM, and DownshiftRPM. These RPM values provide clues
to the engine manager regarding optimal times to shift up or down depending on the engine
RPM. When you're driving using automatic transmission, these values determine whether the
transmission shifts too soon or too late to produce a smooth acceleration curve.