Setup Dev 09 - Dampers

rFactor setups, GTR2 setups, GTL setups, RACE setups, Sim Racing setups
First, lets get some terminology clarified:
I will refer to the upward (compression) stroke of the shock as “compression” or "bump". I will refer to the downward stroke of the shock as “rebound”. We can all argue the true names for each, but I would like to stay consistent with our setup menus in the current simulations.

What a damper does; Dampers counteract the springs natural compressing and unloading by offering resistance against those forces. Dampers do this via hydraulic fluids being forced through small valves inside the damper as the damper compresses and uncompress. A higher damper value equates to greater resistance.

A wheel's maximum grip level will be achieved when the spring is fully compressed. This is when that wheel has maximum weight being translated through the suspension, tire, and to the track. In a generic sense that weight equals grip. How quickly or slowly that spring is allowed to fully compress is the job of the damper. Springs may dictate HOW MUCH weight is transferred, dampers dictate HOW, and even WHEN, that weight is transferred.

The easiest way to begin to understand dampers is in a straight line, under braking or acceleration:
Under braking, much of the car's weight will shift from the rear of the car to the front. The front springs will compress while the rear springs will un-compress or rebound. The dampers follow suit and will compress (front) and rebound (rear). The faster the front springs are allowed to compress to their most-compressed state, the faster the front tires will have maximum grip for that all important braking. A softer compression setting will give the least amount of resistance to the spring compressing, allowing that weight to transfer very quickly once the brakes are applied. The rear damper compression setting will have no effect on what happens here, but the rebound will. A greater rebound setting will resist against the rear springs un-compressing. Since the spring is not allowed to rebound quickly, the rear tires will be somewhat lifted off the ground (exaggerated of course). Softer rebound setting in the rear will allow the rear tires to stay connected with the road and offer more rear-grip during that weight transfer to the front.

Under straight-line acceleration the complete opposite is happening with the rear dampers compressing and the front dampers going into rebound. Surely you will want maximum grip on the rear tires under acceleration, but the front tires may need grip adjustments to prevent under-steer over-steer. You can adjust these condition by adjusting how the rear suspension compresses and how the front suspension rebounds.

The same philosophy can be applied laterally (side to side) as well. Long sweeping corners that do not involve large braking or accelerating will still shift weight to the left and right of the car. How, and how fast, you allow that weight to transfer is up to you and can be adjusted via the dampers.

'Diagonal' damping is where things start getting a bit more complicated, and fun:
Imagine what is happening to the right-front suspension of your simulated racecar as we go barreling into a left turn. As you lift off the throttle and applies brakes the weight of the car is being shifted from the rear of the car to the front. Added to this is a left to right shift as you begin to turn in to the corner. The right-front spring will compress under the weight transfer, and the shock will do the same; compress. A low compression setting will allow that spring to compress quickly, giving that tire it’s full available share of grip very quickly. A higher compression setting will force the spring to compress slower, meaning the weight of the car will not transfer as quickly and maximum grip will still be available, just slightly later in the entry of the turn. The spring will fully compress no matter what the shock’s compression setting is, but you can dictate WHEN, and in turn dictate the handling of the car during this phase of the corner. The opposite is happening to the left-rear of the car as it is losing weight both from braking and turning as that spring and shock is in a rebounding phase. How quickly that suspension is allowed to rebound dictates the grip for that wheel during this transition. If the shock is set to a low rebound setting then the spring will be allowed to easily un-compress and maintain maximum grip. If set to a higher rebound, the spring will not be allowed to rebound as quickly and the grip will be reduced as the wheel is being pulled off the racing surface. You can imagine how this might effect the car during this corner-entry phase and how you can adjust it to suit your needs.

As the car approaches the middle of the corner, the springs are already at full compression and/or rebound, and the dampers would be as well. Dampers do not play a roll in the handling of the car once this has occurred, as dampers need to be in-travel (either compressing or rebounding). If the dampers are not in motion, they can not offer resistance.

As we pass the point in which the car is at a settled state in the middle of the turn, you begin to apply throttle for maximum exit speed. Applying the throttle will shift weight to the rear of the car, and as we ease out of the steering the weight will begin shifting back towards the left. As you apply throttle the right-rear shock begins to go into more compression, though would already be near it maximum compression. Since we can’t make this spring and shock compress any further, actions can be taken from the diagonal corner (left-front). Altering how that spring deals with the weight shifting will increase or decrease overall front grip.

There are hundreds of variables in dampers, even though there are only four dampers on the car. Changing one will alter the other three as well. One adjustment to the right-front rebound will alter how the weight is shifted to the left-front wheel (Lateral weight transfer in quick succession turns like chicanes or long sweepers), the left-rear (diagonal weight transfer in corners while braking or accelerating), and the right-rear (Longitude weight transfer under braking and acceleration). You have to be aware how one change will effect the other aspects. As usual, any setup change is a compromise between a gain in one area and a loss in another.

If your car is equipped with fast-damping adjustments, everything above still applies but only when the suspension is in "fast motion". An example of your suspension moving in fast-motion is when you are hopping over curbing, something I like to call "curb smacking". This is when you are shocking the suspension into movement in a very short time frame. Hitting a curb at speed (like you might at Monza, or the final chicane at Magny-Cours) is forcing your suspension to compress or rebound in a much shorter time frame then normal weight transitions. This is where fast-damping comes into the mix.

Below, I made up a basic cheat-sheet. There is a lot more that can be done with spring and shock combinations and the only way to get to know it all is to experiment with it, but these cheat sheets can help guide you in the proper direction with some standard handling problems.

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