Moonbeam Trials with GTA 3 Handling

In this tutorial I will demonstrate my style of making handling setups. I expect you have not replaced this vehicle yet, which makes it the best vehicle to alter. With its short wheelbase it should be fairly agile, with lots of weight shifting, plus the low grip should make it oddly fun to drive. Plus, you will have learnt how to set up a car. You should have a Moonbeam (small people carrier) parked in your Staunton garage and save there.

To do this tutorial you will need to make sure you are using the original handling. Open the GTAIII\data\handling.cfg file and we can begin.

The First Settings

Once you locate the MOONBEAM line you will see it looks like this:

MOONBEAM  2000.0 2.2 5.5 2.5 0.0  0.00  0.10 50 0.90 0.80 0.47 5 150.0 15.0 F D  5.50 0.60 0 30.0  1.40 0.100 0.20 0.10 16000 0.35 -0.15 0.50 000A 0 3

Now to make some changes based on my experience.


Currently set to 2000.0 which means two tonnes. I think this is a bit too much, so set it to 1800.


Next values are width, length and height in that order, measured in metres. I think they should be 1.9, 5.0 and 1.9 in that order.

Centre of Mass

The three values. When you increase these numbers, the first moves it towards the left, the next moves it foward and the last moves it upwards.

I think values of 0.0, 0.06 and 0.40 would suit the Moonbeam. That moves the mass to the middle of the car’s width, quite far forward and quite high up.


You will see that the next value is 50. It is the percentage of the vehicle which must be below underwater for it to “drown” and stop driving. Setting this to -1 makes the car go straight through the water and land and respawn on the nearest road!


0.90 is the Traction Multiplier, in this case meaning 90% of the value set in the surfaces.dat file. Set it to 0.65 I think.

0.80 value is the Traction Loss and it determines how the grip changes when put under stress. For a front-drive vehicle you should make it about the same as the multipler because they do not behave much different when under stress. Therefore, a value of 0.55 will do.

Grip Bias

0.47 is the Traction Bias between the front and rear wheels as a percentage. A value of 0.47 means that only 47% of overall grip is at the front, with 53% on the rear. I would set this to 0.50 because this vehicle would have the same tyres at both ends.

Straight Line Performance

5 is the Number of Gears and I would keep it as that.

Next is the Top Speed and after that is the Engine Acceleration. This vehicle would not be a fast one, so a Top Speed of about 140.0 and an Engine Acceleration of 9.0 will be plenty.

Drivetrain & Fuel

After those there are two more transmission settings. The letter F is for Drive Type. F means front wheel drive, which is correct for a vehicle like this.

After that, the D is for Engine Type. D indicates it is a diesel engine, which is fine for a vehicle like this.


Brake Force and Brake Bias are next. I always set the brakes so that the wheels do not quite stop or “lock” when on a dry road but will if on a wet road or on grass. To start with we will try a Brake Force of 4.5.

Brake Bias works like Traction Bias, so 0.60 means 60% of the force is sent to the front wheels and the rest to the rear. Let’s use that.

There is now a 0 which is used to indicate if the vehicle has ABS or not. This system is not actually used in GTA, so I always leave it set to 0.


Afterwards is 30.0 which indicates the maximum Steering Angle for this vehicle in degrees. This is a reasonable value so I would leave it as that.

Springs & Dampers

The next two values are for suspension which is very complicated and best covered by my suspension tutorial.

For the Moonbeam I think the first value should change from 1.40 to 1.00, then the second value should be changed from 0.100 to 0.125. These are the Spring Force and Damper Force, respectively.

Driving Position

0.20 is the distance in metres for the Seat Offset from the door to the seat. This value is fine.


After that is the Collision Damage Multiplier, which determines how strong the engine is. A low value of around 0.01 will mean the vehicle can take a lot of hits before the engine catches fire, whilst a high value like 2.00 will make it very fragile.

For the Moonbeam, a value of around 0.40 is reasonable.


I am not sure if the next value is used but it is supposed to be the Value of the vehicle in dollars. It may be that this is used to work out the Value of property damaged statistic by adding this to your score every time you destroy one?

Suspension Geometry

Now we reach the final three values for suspension:

Upper Limit:
In meters. Sets how high the wheels can bounce up inside the wheel arches.
Lower Limit:
In metres. Sets the ride height in meters upward, meaning it is normally a negative number so the wheels are moved down below the vehicle.
Suspension Bias:
Relative strength between the front and rear suspension. Measured the same as any other bias.

For the Moonbeam, the Upper Limit could be 0.30 and the Lower Limit about -0.20 I think. This means the wheels can move upwards by 0.30 meters (30cm) and the vehicle has a ride height of 0.20 meters (20cm). The Suspension Bias should be 0.50 so the suspension is equal.

Special Features

Vehicles can have many special attributes called ModelFlags, such as the direction their boot lid hinges. These are set by the bunch of hexadecimal digits here. It is complicated to put them together by hand so I recommend using my CFG Studio 2 program.

I won’t change the flags already set for this vehicle.


You should now have a setup which looks like this:

MOONBEAM  1800.0 1.8 4.9 1.9 0.0  0.06  0.40 -1 0.65 0.60 0.50 5 140.0 09.0 F D  4.50 0.60 0 30.0  1.00 0.125 0.20 0.40 16000 0.35 -0.20 0.50 000A 0 3

It takes a lot of thinking and testing to make a decent handling setup. We have done most of the thinking, now comes the testing!

Testing the Setup

Staunton Island is the best location for testing handling. After you become familiar with the layout of the roads you can test your car down long straights, through steeply crested chicanes, around double-apex curves and sharp junctions. Here is an image of my route.

Your best bet is to plan your route before you start driving else you will just drive round all day, which is not good use of testing time!

The tests I carried out and the changes I made are listed here:

  1. It is not too bad, not too bad at all. I noticed a lot of wheelspin though, this is caused by the ModelFlags data having boost features turned on. Change the 000A to 0004 to remove these.
  2. The front wheels lock up on dry roads, so we will reduce the Brake Force from 4.5 to 4.0 so they are not put under so much stress.
  3. That is much better now. In fact, that would be the sort of setting I could give user-made cars to be released with.

I have only tested this three times, you should always do it in smaller steps until you become more competent. It has taken me a long, long time to get good at it. I’m still learning!

Closing Statement

Hopefully this has taught you one approach for making handling setups.

It depends on the style of handling you are aiming for. If it is a stunt car you are setting up then rather unrealistic values could be used. Always refine it, always make sure it is versatile.

An lowrider which cannot drive over bumps or kerbs is not much use to anyone!