Bump Stiffness Explanation: The shocks on these stock cars are two-way adjustable, meaning “Bump” and “Rebound” are independently adjustable. The “Bump” setting refers to the stiffness rating of the shock when it is in compression. A higher number will mean a stiffer shock under compression, and a lower number will mean a softer shock under compression.
What does it do: Many people use the bump adjustment for many different things. It does control the weight transfer to the front (stiffer bump will resist weight moving to the nose), but it can also be used to control how quickly the suspension travels.
On the Front End: The bump setting on the front will control how quickly the nose “drops” under braking, when the springs bind, and how quickly weight will transfer to the front. Generally, on the left front, decreasing the left front bump will move weight to that corner faster, and help with turn in. Decreasing the right front bump will shift weight to that corner faster, and make the car tighter on entry. Increasing the bump will do the opposite for each corner.
On the Rear End: The rear bump setting will mainly control how the car behaves on corner exit. If you lower the bump on both sides of the rear, the car will have more traction under throttle, but will be tighter on the exit. Separately, the shocks will do the same as the springs: a stiffer right rear shock will loosen the car under throttle, while a stiffer left rear shock will tighten the car under throttle. Lowering the right rear bump setting will tighten the car under throttle, and lowering the left rear bump will loosen the car under throttle.
Tips: It’s difficult to explain how the shocks work, I’d need an entire new guide for that. However, testing will show you what works and what doesn’t work. If the front end feels really “floaty” when it’s moving up and down, increase the bump in the front shocks. If it feels to “rigid”, decrease the bump, and the same goes for the rear end.
Not my writings
