Yorkie065 this week gets under the skin with dampers and will guide you through how to fine-tune your setup to get the car handling exactly as you want it.
Adjustment of the Bump Stop is used to prevent the car from bottoming-out due to lower ride heights, softer spring rates, or strong dips and bumps on the track surface.
A longer Bump Stop will become engaged sooner with less suspension movement, preventing the suspension from compressing any further by dramatically increasing the spring rate on that wheel. This can help prevent the car scraping along the track surface, but mechanical grip and general handling balance may be negatively affected while riding on the bump stop.
As a general rule, set the Bump Stops long enough to help prevent the car bottoming-out, but not so long that they are active during normal driving.
SLOW DAMPING (BUMP & REBOUND)
Slow Damping controls the car’s suspension compression in response to driver inputs. It controls the dynamic weight transfer and overall motion of the main chassis relative to the track surface when the car turns, slows, and accelerates. Most fine-tuning of the handling balance will be done with the Slow Damping settings.
Increasing the Slow Bump value will make the car react quicker and sharper in response to driver inputs, resulting in a more responsive car when changing direction.
Too much Slow Bump, however, can reduce mechanical grip, causing more “snappy” behaviour. It can also result in a car that is prone to sudden understeer when the front is too stiff, or sudden oversteer when the rear is too stiff.
Slow Rebound Damping controls how the suspension extends back to its normal position after being compressed. Too much or too little Slow Rebound Damping for a given spring rate can cause the tyre to lose contact with the road, thereby reducing mechanical grip.
Adjust the front and rear Slow Damping to find the right balance for the type of circuit you’re on, and also your own driving style.
FAST DAMPING (BUMP & REBOUND)
Fast Bump and Rebound Damping controls the tyre reactions over bumps and kerbs. Its job is to keep the rubber on the ground over rapid surface undulations. In bumpy sections of track, too much Fast Bump at the front can cause understeer, too much at the rear can cause oversteer.
To tune Fast Damping, pick a bumpy section of the track. Start with low Fast Bump and Rebound settings, and increase them until the front understeers, then back off a few clicks. Repeat this process for the rear until it oversteers on that bumpy section and, again, back off a few clicks. Now check the car’s response to the rest of the track, and over kerbs. This may require softer settings than the bumpy section: perfection is rare, and compromise is key.
Tune Fast Damping in sync’ with Spring Rate changes. The stiffer the spring, the stiffer the Fast Rebound setting.
Bump and Rebound Transition allows for the advanced control of the switch from Slow to Fast Damping, without affecting their damping rates.
Increasing the Bump Transition will make the transition from Slow to Fast Bump longer: Here, the Slow Bump damper rate will act for longer before transitioning to the Fast Bump, and provide more overall damping.
Decreasing the Bump transition will make the switch faster: Here, the Slow damper rate will act for a shorter period of time before switching to the Fast, and result in less overall damping.
If you tune this together with the Slow and Fast Bump, you can set the Slow Bump to a stiffer value with a low Bump Transition rate to achieve a stiffer initial damping, which then drops off quickly. For slower and more mellow initial damping, set the Slow Bump to a softer value, and use a higher transition rate.
Rebound Transition allows control of the switch between Slow and Fast Rebound of the dampers, without affecting their damping rates.
Increasing the Rebound Transition will make the transition from Slow to Fast Rebound longer: Here, the Slow Rebound damper rate will act for longer before transitioning to the Fast Rebound, providing more overall damping. Decreasing the Rebound transition will make the switch faster: Here, the Slow Rebound damper rate will act for a shorter period of time before switching to the Fast, and result in less overall damping.
If tuned together with the Slow and Fast Rebound rates, setting the Slow Rebound to a stiffer value with a low Rebound Transition rate will result in a stiffer initial damping, which then drops off quickly. For slower and more mellow initial damping, set the Slow Rebound to a softer value, and use a higher transition rate.
Jussi’s Suspension Calculator
Jussi’s Suspension Calculator is a crucial tool when it comes to tuning your dampers. Use it to input your changes to spring rates and damper ratios, and it will highlight whether you are going too far in either direction, thereby making them fall out of their critical ranges which can be detrimental to your car’s handling. You can find the calculator, along with some instructions and further explanations, here.
Now sit back, relax, and watch as Yorkie065 explains the black magic behind damper tuning.