The core idea
Every time you brake, the car's weight shifts forward. Every time you accelerate, it shifts back. Every corner, it shifts sideways. The tires with the most weight on them have the most grip — full stop.
Why it matters
A tune is mostly an answer to: how do I control where the weight goes, and when? Springs decide how much. Dampers decide how fast. ARBs decide which end goes light first. Brake bias decides which axle does the slowing.
Three practical rules
- The stiffer end loses grip. If your front ARB is stiffer than your rear, the front rolls less and slides first. To fix understeer, soften the front (or stiffen the rear).
- Bumps and dampers fight each other. If the car skips sideways across a kerb, your dampers are slowing the springs faster than the surface lets them recover. Soften bump 1-2 clicks.
- Trail braking is weight transfer as a tool. Staying lightly on the brake while turning keeps weight on the front, which is exactly where you need grip to rotate. See the trail braking guide.
A quick gut-check
If you're ever confused by a tune problem: ask "which corner of the car has the weight right now, and which one has none?" The unloaded corner is the one breaking traction.