its been a while since the last setup guide. So time for Part 8 - Anti-Rollbars.
We have already introduced Anti-Rollbars in Part 2 to get the basics. I strongly suggest that you have a basic understanding out of that tutorial.
So why are we speaking in depth about Anti-rollbars so late in Part 8?
Now lets rethink about what Anti-Rollbars do.
As the name already suggests an Anti-Rollbar counterworks the roll of the chassis in a corner. So you can influence the weight transfer in corners with the Anti-Rollbars.
Anti-Rollbars are like 'sideways springs', they work laterally.
If one side of the suspension is compressed, one end of the bar is lifted. Due to that fact the other end of the bar lifts, pulling the other side of the suspension up, which results in more resistance to chassis roll.
How far and how strongly the other side will be pulled up depends on the stiffness and the thickness of the bar used. A thin bar will flex a lot, so it won't pull the other side up very far, letting the chassis roll deeply into its suspension travel. So the thicker the bar, the less chassis roll. By the way in F1 2011 thin bar equals value 1 and the bigger the value the thicker the bar. So 11 is the thickest bar available.
Note that the bar only works when one side of the suspension is extended further that the other, ore in other words, when the car is cornering. When both sides are equally far compressed, e.g. when the car is braking, the bar has no effect. So Anti-Rollbars only affect the lateral balance of the car, not the longitudinal balance.
Suppose now we add Anti-Rollbar at the rear, so use a thicker rear Anti-Rollbar. When the car enters a turn, the chassis starts to roll. Normally the suspension on the outside of the turn would compress, and the on on the inside would extend, resulting in a lot of more pressure on the outside tire. With the Anti-Rollbar however the suspension on the inside will be compressed too, so the chassis will roll less, and the rear of the car will be lower. So we will have more consistent traction on the rear during corner entry. But what happens at the middle of the turn? Without the Anti-Rollbar the chassis would stop rolling when the roll torque is fully absorbed by the outside spring.
But with the Anti-Rollbar, some of that torque is absorbed by the Anti-Rollbar, and used to compress the inside suspension. So the outside suspension won't be compressed as much as it normally would, making the rear of the chassis sit up higher than normal, so less pressure is in the rear of the car, and more at on the front. So we have little less rear traction. Thats no problem on a smooth track because the weight is distributed more evenly over the rear tires, but on a bumpy track this would mess up our rear grip level in the corner middle rapidly. But the good side effect is that you will have more front grip cause of more pressure on the front. Adding Anti-Rollbar at the front of the car has a similar, but opposite effect. It decreases the initial steering and stops the front from 'biting' into the surface too much, making the turning radius big and smooth.
So when you have to much oversteer while turn in and in cornering reduce the rear Anti-Rollbar
When you have to much understeer raise the front antirollbar.
The more bumpy the circuit is, the less Anti-Rollbar you should give.
But keep in mind that Anti-Rollbars only fine-tune the alignment and suspension settings.
So the best you should take out of this tutorial is that with Anti-Rollbar Settings you can clue out a bit of oversteer or understeer characteristic.