BMW M5 CS Tuning Guide — Best S1 Setup

Class Range: S1 900 | Base Horsepower: 635 hp | Drivetrain: M xDrive | Weight: 1825 kg | Best Class: S1 900

Honestly, the M5 CS is a monster of a performance sedan in FH6. 1825 kg sounds heavy, right? But you genuinely don't feel it behind the wheel — M xDrive's tuning makes this near-two-ton car more agile through corners than plenty of sports cars weighing 300 kg less. The twin-turbo V8's torque shoves you from 1800 rpm and doesn't let up all the way to 7200 rpm.

In stock form, the M5 CS's biggest problem is its corner-entry attitude — heavy body, big inertia, so it's easy to push wide in fast, tight corners. There's also a slight rear-axle bounce on corner exit caused by the stock dampers' overly fast rebound. Fix both of these and the car basically runs with the supercars in S1 class.

My favorite thing about the M5 CS is its split personality — quiet and comfortable when cruising, then like a rhino that got kicked in the rear when you step on it. But on track you have to forget it's a four-door sedan and tune it to supercar standards.

Best Tuning Setup for S1 900

The Track build's philosophy is trading power for lap time. At 1825 kg you can't win by stacking horsepower — those extra few dozen horses are worthless in corners, and the weight makes them even harder to manage. With 710 hp and this tune, the Track build laps Guanajuato a full second faster than the Sport build.

Tuning Parameters — Every Setting Explained

Tire Pressure

Front 2.2 bar / Rear 2.1 bar. The car is so heavy that pressures have to run high, otherwise the sidewalls flex too much and hurt steering precision. The front runs higher because it carries more load on turn-in. Pressures settle around 2.4 once warm.

Transmission

Final drive ratio 3.55. The M5 CS has 8 forward gears, but 6, 7, and 8 are basically useless on track. Tighten gears 1–5 so the V8's torque plateau shoves you out of every corner. A top speed of 320 km/h is enough for 99% of events.

Alignment

Front Toe 0.0 / Rear Toe +0.1, Front Camber -2.0 / Rear Camber -1.5, Caster 6.8 degrees. The negative camber is more aggressive than on a normal sports car because of the weight — mid-corner the tires need more camber to keep the tread flat on the ground.

Anti-Roll Bars

Front 35.0 / Rear 28.0. The front bar is cranked up stiff to fight the 1825 kg's corner-entry roll and understeer. The rear bar stays relatively soft because the rear axle needs independent movement to keep traction on exit.

Springs

Front 720 / Rear 680 (lbs/in). These are the stiffest springs in this lineup — no way around it given the weight. Any softer and the cornering roll would make you afraid to get on the throttle.

Damping

Rebound Front 10.5 / Rear 9.8, Bump Front 7.0 / Rear 6.5. Rebound is slowed down a lot compared to stock, specifically to fix the rear-axle bounce. The stock rebound was too fast — over road joints the rear wheels would lift slightly and make corner-exit traction feel choppy.

Aero

Wing angle medium-high, front downforce at medium. The M5 CS's issue is rear-end lift in fast corners, so it needs rear downforce to pin the tail down.

Brakes

Brake balance front-biased at 49%, pressure 130%. Stopping 1825 kg takes serious braking force. The carbon-ceramic brakes are already excellent, so just turn the pressure up.

Differential

Front diff Accel 55% / Decel 25%, Rear diff Accel 75% / Decel 35%, center diff 55% rearward. M xDrive is already rear-biased; adding a 55% rear bias plus 75% rear accel lock gives the rear axle a touch of playful oversteer on exit without ever getting out of control.

Driving Tips

The most critical skill in the M5 CS is choosing your braking points. At 1825 kg, your stopping distance is about 10–15 meters longer than a supercar in the same class, so you have to brake early. Use the weight on corner entry — lift off and the tail naturally drifts out a touch, so use that to help rotate the car. Don't rush to full throttle after the apex; the M5 CS's torque is too brutal, and if you get on it too early the front wheels slip, Quattro shoves power forward, and you understeer like crazy. Give it half throttle first to let the rear squat, feel the rear tires bite, then floor it. The car actually gains an edge in the rain — AWD plus all that weight means it's far more planted in the wet than a RWD supercar.

Best Race Types