FH6 Spring & Damper Tuning — Suspension Setup Masterclass

Springs and dampers are the foundation that every other tuning setting sits on top of. If your springs are wrong, no amount of camber or differential tweaking will fix the car — it'll just mask symptoms. The suspension is what keeps your tires in contact with the road, and in FH6, tire contact patch is everything. I've spent more time on spring and damper tuning than any other area, and the patterns are surprisingly consistent once you understand what each slider is actually controlling. Here's the master class.

Springs vs Dampers — What Each Controls

Springs support the weight of the car and absorb the initial impact of bumps. They determine how much the car leans, dives, and squats. Stiffer springs = less body movement = sharper response but rougher ride and less grip over bumps. Softer springs = more body movement = more mechanical grip on rough surfaces but sloppy handling and delayed response. Dampers control the speed at which the springs compress and extend. They don't support any weight — their entire job is controlling spring movement speed. Without dampers, the car would bounce endlessly after every bump because the spring has no way to dissipate energy. Too much damping and the suspension can't respond fast enough to bumps — the wheel skips over the surface instead of following it. Too little damping and the car oscillates and feels floaty. The spring sets the limit; the damper controls how quickly you reach it.

The practical takeaway: change springs for how the car handles overall — the big-picture balance between responsiveness and grip. Change dampers for how the car behaves over specific surface features — bumps, curbs, transitions, and weight transfer events. The two settings work together but solve different problems. A car with perfect springs and terrible dampers feels harsh and skittish. A car with perfect dampers and terrible springs leans too much but absorbs bumps beautifully. You need both right, and you tune them in that order: springs first, then dampers.

Spring Rate — Stiff vs Soft and the Handling Bias

Front-to-rear spring balance determines the car's handling bias. Stiffer front springs relative to the rear create understeer — the front resists compressing and the car pushes wide. Stiffer rear springs relative to the front create oversteer — the rear is more willing to rotate. The standard setup is front springs 10-20% stiffer than rear because the front carries more load under braking (weight transfer pushes the nose down) and needs the extra rate to prevent excessive dive. On a mid-engine or rear-engine car, the weight distribution is rear-biased, so front and rear spring rates might be closer to equal or even reversed — a Porsche 911 with 40/60 front/rear weight distribution might run 550 front / 600 rear springs instead of the usual front-biased setup.

The Bounce Test for Spring Rate

There's a simple way to check if your spring rates are in the ballpark without running a single lap. Buy the car, install the race suspension, set your spring rates to the starting values above, then drive in a straight line at about 60 mph and aggressively swerve left and right. If the car responds instantly with no hesitation, springs might be too stiff — you're sacrificing grip for response. If the car feels like it's on a delay — you turn the wheel and the body leans, then the car changes direction a split second later — springs are too soft. The sweet spot is immediate response without harshness. The car should change direction the moment you turn the wheel, but it shouldn't feel like the tires are skating. Another test: find a bumpy section of road (the cobblestone areas on the FH6 map are perfect for this) and drive through at speed. If the car skips and chatters, the springs are too stiff. If it wallows and takes too long to settle after each bump, the springs are too soft. The car should absorb bumps without drama but settle immediately after each one.

Damper Settings — Rebound vs Bump Stiffness

Bump damping (sometimes called compression) controls how fast the spring compresses when you hit a bump or the car rolls into a corner. Higher bump stiffness means the suspension resists compressing quickly — this makes the car feel firm and responsive but harsh over bumps. Too much bump stiffness and the wheel can't move out of the way fast enough when it hits a bump, so the entire car gets lifted instead. Rebound damping controls how fast the spring extends back after being compressed. Higher rebound stiffness means the spring extends slowly — this controls body movement and keeps the car from bouncing. Too much rebound and the suspension "packs down" over repeated bumps — each hit compresses the suspension and it can't extend back before the next hit, so the car gradually loses suspension travel. Too little rebound and the car oscillates after every bump, feeling floaty and disconnected.

The golden rule: rebound should be 1.3x to 1.5x higher than bump on all four corners. This ratio exists in real-world race car setup for a reason — the spring naturally wants to extend faster than it compresses (spring physics), so you need more rebound damping to control the extension than you need bump damping to control the compression. FH6's physics model respects this. If you're running 5.5 bump in the front, run 7.5-8.5 rebound. If you're running 4.0 bump in the rear, run 5.5-6.5 rebound.

Damper Tuning for Curbs and Bumps

Curbs are where damper tuning separates fast cars from slow ones. A car with too much bump damping will get unsettled every time it touches a curb — the wheel can't absorb the impact and the whole car jumps sideways. A car with too little bump damping will compress fully onto the curb and then rebound violently, creating the same instability. The sweet spot: the car should use curbs as an extension of the track, not as an obstacle. When you hit a curb at corner exit, the car should absorb it without changing direction. If it jumps sideways, reduce bump damping by 0.5 on the affected axle. If it wallows and takes too long to recover, increase rebound by 0.5. I tune dampers on the curb-heavy sections of the Castillo Del Sol circuit specifically because the curbs there are aggressive enough to expose damper problems immediately. A car that handles those curbs cleanly is a car with correctly set dampers.

Rally Spring Setup — Soft, High, and Soaking It Up

Rally suspension is the exact opposite of road racing suspension. On dirt, mechanical grip comes from keeping the tires in contact with a surface that's constantly changing. Stiff springs bounce the car off every rut and the tires spend more time in the air than on the ground. Soft springs let the suspension absorb the terrain so the tires stay planted. The tradeoff is body control — a soft rally car leans dramatically in corners and feels floaty on jumps. The setup philosophy for rally: run springs as soft as you can tolerate, with enough damping to control the body movement without making the car skittish. Spring rates of 250-350 front / 200-300 rear are the starting point. Ride height at maximum or near-maximum — you need the suspension travel for landing jumps and absorbing deep ruts. Bump damping between 3.0-4.0 so the suspension compresses freely on impact. Rebound damping between 4.5-6.5 to control the car after jumps and prevent excessive bouncing. A well-tuned rally car feels loose and reactive — it should slide predictably and recover quickly, not grip like a road car but not feel completely disconnected either. The dirt racing techniques guide covers how driving style interacts with rally suspension setup.

How to Read the Car's Behavior and Diagnose Suspension Problems

Car pushes wide on corner entry under braking: front springs too soft — the nose dives too much, weight transfers forward, and the rear goes light. Stiffen front springs by 10-15% or increase front bump damping to slow the dive.

Car oversteers on corner exit when you get on power: rear springs too soft — the rear squats too much under acceleration, transferring weight off the front and making the car loose. Stiffen rear springs by 10-15%.

Car skips and chatters over bumps: springs too stiff or bump damping too high. Soften springs first (bigger change), then reduce bump damping if the problem persists on specific surface types like curbs.

Car oscillates after bumps: rebound damping too low. The spring is extending back without enough control and the car bounces. Increase rebound by 0.5-1.0.

Car feels harsh on impact but doesn't skip: bump damping too high. The spring can compress but the damper is restricting it. Reduce bump by 0.5.

Car bottoms out frequently: springs too soft or ride height too low. Raise the car or stiffen the springs — bottoming out is worse than either solution individually because it causes sudden, unpredictable grip loss.

These symptoms are consistent regardless of the car or the tuning approach. A D class hatchback and an S2 hypercar will both push wide under braking if the front springs are too soft — the physics don't care about the price tag. Learn the symptoms, make one change at a time, and test. The tuning calculator can model these interactions before you commit to a setup, which is especially useful when you're trying to figure out whether it's the springs or the dampers causing a particular handling characteristic.