Almost
all setup adaptations will require gear ratio adjustments. GRE
provides a gearing chart (example at right), a very useful tool
for helping you to create optimal gear ratios for any car at any
track.GPL's cars all have different chassis characteristics. Some are light, some are heavy. Some are short and wide, some are long and relatively narrow. Weight distribution varies, with some having more weight concentrated over the rear wheels. See Chassis Characteristics and Chassis Weights and Dimensions for details.
The Lotus GP car has wider rear rims than the other GP cars, which gives it more grip at the rear relative to the front, so it will need its balance set for more oversteer than the other GP cars. However, the Lotus Trainers lack these wider rims. This means the anti-roll bar settings of the Lotus Trainers will be fairly similar to the other Trainers, while the Lotus GP car will have a stiffer rear anti-roll bar and softer front anti-roll bar compared to the other GP cars.
Using the redline dots on GRE's gearing chart, adjust gear ratios according to the cars' relative power, weights and drag.
A more powerful, lighter, or less draggy car can run taller gear ratios, so its redline dots will be slightly farther to the right than those of a less powerful, heavier, or more draggy car.
A more torquey engine like the Repco or Cosworth will have taller low gears and will have the top gears grouped more closely together than a peaky engine like the BRM.
The Trainers have identical engines, but gearing must still be adjusted because each chassis has unique rear tire diameters as well as unique weight and drag. Again, the redline dots on GRE's gearing chart provide a useful tool. Set the gears so the redline dots are the same as another setup for the same track, allowing for differences in weight and drag.
Brabham, Lotus, Ferrari, Eagle to Coventry, Murasama, BRM.
To avoid bottoming the suspension due to the higher weight, increase spring rates. It may also be necessary to increase ride height.
Stiffen the anti-roll bars due to increased weight transfer caused by higher weight (and higher CG in the case of the BRM).
For chassis with equal weight distribution, increase front brake bias due to reduced weight transfer.
For chassis with more rearward weight distribution (BRM, Murasama), decrease front brake bias.
For chassis with more forward weight distribution (Coventry), increase front brake bias.
Adjust the anti-roll bars to tune the balance as necessary.
Remember that the GP Lotus has more rear grip relative to the front than any other car, so adapting from the GP Lotus to another car will require a much softer rear anti-roll bar and a much stiffer front anti-roll bar.
BRM, Murasama, Coventry to Eagle, Ferrari, Brabham, Lotus.
The lighter weight may allow reduced spring rates without bottoming the suspension. It may also be possible to decrease ride height.
Soften the anti-roll bars due to reduced weight transfer.
For chassis with equal weight distribution, decrease front brake bias due to reduced weight transfer.
For chassis with more rearward weight distribution (Lotus - see footnote; Eagle, Ferrari), decrease front brake bias.
For chassis with more forward weight distribution (Brabham), increase front brake bias.
Adjust the anti-roll bars to tune the balance as necessary.
Remember that the GP Lotus has more rear grip relative to the front than any other car, so adapting to the GP Lotus from another car will require a much stiffer rear anti-roll bar and a much softer front anti-roll bar.
Brabham, Coventry, Murasama, Eagle to Ferrari, Lotus, BRM.
Increase the steering ratio (this will slow it down).
Soften the anti-roll bars due to reduced weight transfer.
Increase front brake bias due to increased weight transfer. (Except Lotus GP car; see footnote.
Adjust the anti-roll bars to tune the balance as necessary. If the car is unstable or generally oversteers, soften the rear anti-roll bar and stiffen the front.
Remember that the GP Lotus has more rear grip relative to the front than any other car, so adapting to the GP Lotus from another car will require a much stiffer rear anti-roll bar and a much softer front anti-roll bar.
Ferrari, Lotus, BRM to Brabham, Coventry, Murasama, Eagle.
Decrease the steering ratio (this will speed it up).
Stiffen the anti-roll bars due to increased weight transfer.
Decrease front brake bias due to reduced weight transfer.
Adjust the anti-roll bars to tune the balance as necessary. If the car is unresponsive in turn-in or generally understeers, stiffen the rear anti-roll bar and soften the front.
Remember that the GP Lotus has more rear grip relative to the front than any other car, so adapting from the GP Lotus to another car will require a much softer rear anti-roll bar and a much stiffer front anti-roll bar.
The GP chassis are identical to their Trainer counterparts in size and weight. Only the engines and tires differ.
The Advanced Trainers have 270 hp vs. 350 to 430 in the GP cars, and they have somewhat less grip. The Basic Trainers have 140 hp and even less grip. (See Engine Power and Redlines and Engine Torque and Power Curves for more details about the engines.)
The GP cars have rear tires that are considerably wider than their front tires. Although the Trainers in GPL look identical to the GP cars, they model cars with narrower tires and therefore less grip.
From empirical observation of the behavior of the Trainer versions of the various chassis, the Advanced Trainers seem to model rear tires that are only slightly wider than their fronts, while the Basic Trainers have front and rear tires of approximately the same size. This means that the balance settings for a given chassis will differ from class to class, with the Advanced Trainer set for more understeer than the GP car, and the Basic Trainer set for more understeer than the Advanced Trainer.
The Lotus GP car has wider rear rims than the other GP cars, which gives it more grip at the rear relative to the front, so it will need its balance set for more oversteer than the other GP cars. However, the Lotus Trainers lack these wider rims. This means the anti-roll bar settings of the Lotus Trainers will be fairly similar to the other Trainers, while the Lotus GP car will have a stiffer rear anti-roll bar and softer front anti-roll bar compared to the other GP cars.
Alter gear ratios for lower top speed.
Stiffen front anti-roll bar and soften rear anti-roll bar for more understeer to compensate for narrower rear tires.
Reduce anti-roll bar total slightly since there is less grip and therefore less roll.
Reduce front brake bias since there is less grip and therefore less forward weight transfer under braking.
On high-G tracks, it may be possible to reduce spring rates and/or lower the ride height slightly since the lower speeds will induce less vertical load.
Stiffer dampers may be beneficial, to make the less powerful and less grippy Trainers more responsive to power and brake inputs.
Alter gear ratios for higher top speed.
Soften front anti-roll bar and stiffen rear anti-roll bar for less understeer to compensate for wider rear tires.
Increase anti-roll bar total slightly since there is more grip and therefore more roll.
Increase front brake bias since there is more grip and therefore more forward weight transfer under braking.
On high-G tracks, it may be necessary to increase spring rates and/or raise the ride height slightly since the higher speeds will induce more vertical load.
Softer dampers may be beneficial, to make the more powerful and more grippy GP cars less sensitive to power and brake inputs.
Alter gear ratios for lower top speed.
Adjust balance for more understeer since the Basic Trainer rear tires seem to have less grip in proportion to the front. Soften the rear anti-roll bar. This will also reduce overall roll resistance slightly, which is appropriate since there is less grip and therefore less roll.
Reduce front brake bias since there is less grip and therefore less forward weight transfer under braking.
On high-G tracks, it may be possible to reduce spring rates and/or lower the ride height slightly since the lower speeds will induce less vertical load.
Alter gear ratios for higher top speed.
Adjust balance for more more since the Basic Trainer rear tires seem to have less grip in proportion to the front. Stiffen the rear anti-roll bar. This will also increase overall roll resistance slightly, which is appropriate since there is more grip and therefore more roll.
Increase front brake bias since there is more grip and therefore more forward weight transfer under braking.
On high-G tracks, it may be necessary to increase spring rates and/or raise the ride height slightly since the higher speeds will induce more vertical load.
Most of the changes from one circuit to another involve gearing and alterations to adapt the chassis to the vertical loads induced by the circuit.
For high speed circuits, a slightly slower steering ratio (numerically higher) may be beneficial. Softer dampers may also be appropriate.
For circuits with decreasing radius corners or curved braking zones, a more stable chassis (i.e., with more understeer) and more forward brake bias will help the driver cope with the instability induced by the forward weight transfer under braking in the curved braking zone.
Soften spring rates, lower ride heights, and/or reduce overall anti-roll bar stiffness.
Adjust balance for more neutral handling by softening the front anti-roll bar and stiffening the rear.
Stiffen spring rates, raise ride heights, and/or increase overall anti-roll bar stiffness.
Adjust balance for more understeer by stiffening the front anti-roll bar and softening the rear.
Almost
all setup adaptations will require gear ratio adjustments. GRE
provides a gearing chart (example at right), a very useful tool
for helping you to create optimal gear ratios for any car at any
track.
If you already have a setup for another car of the same class for a given track which works well, set the top speed at redline for the new setup to the same figure as the existing setup for that circuit. Then set the lower ratios to follow a similar curve, using the redline dots on GRE's gearing chart for reference.
Further adjustments may be necessary to fine tune both top gear and the lower gears, but this technique should quickly get you to a reasonably close gearing setup.
The GP Lotus is an exception in terms of brake bias because it has more rear grip due to its wider rear rims. This gives it more grip in the rear, so it can accommodate less front brake bias than other cars with the same weight distribution. This is not true of the Lotus Trainers, however.