BMW Z4 GT3

TYRES

• Slick (Soft compound), Front: 22.5 PSI cold / ~27°C optimum settling to ~26–27 PSI hot, Rear: 22.0 PSI cold / ~27°C optimum settling to ~26–27 PSI hot. No blankets assumed — expect first-lap undertemp; optimal window for Z4 GT3 slicks is approximately 75–85°C carcass/tread for peak grip.

ELECTRONICS

• TC: 2, ABS: 2, Engine Braking: 4 (mid, to aid rotation into La Source/Les Combes without unsettling rear over kerbs), Brake Bias: 54.5% front (adjustable in cockpit, nudge to 55.5 for La Source if locking rear on entry)

SUSPENSION

• // FRONT
• Ride Height: 55 mm
• Wheel Rate FL / FR: 145000 N/m / 145000 N/m
• ARB: 55000 N/m (soften slightly from default to reduce mid-corner understeer)
• Brake Torque Multiplier: 100 %
• Brake Bias: 54.5 %
• // REAR
• Ride Height: 60 mm
• Wheel Rate RL / RR: 130000 N/m / 130000 N/m
• ARB: 35000 N/m
• Diff Preload: 60 Nm
• Diff Coast: 0.45
• Diff Power: 0.60

DAMPERS

AERO

• Front Splitter: 4 (of typical 0–6 range), Rear Wing: 5 (of 0–10 range) — trimmed down one step from default for Kemmel/Blanchimont top speed, accepting slightly less stability at Eau Rouge in exchange for straight-line pace on a qualifying lap.

KEY SETUP NOTE

• On a single-lap attack, run the rear wing one click lower than a race setup to maximize Kemmel Straight speed into Les Combes — the Z4's stable high-speed platform through Eau Rouge/Raidillon tolerates this trim even flat-out, but you must commit fully through Raidillon on cold tyres since there's no sighting lap to build temperature.

TRACK GUIDE

• La Source: brake as late as possible but in a straight line — trail brake to the apex, this is the biggest lock-up risk on the lap with cold fronts.
• Eau Rouge/Raidillon: flat in 6th gear if committed early with a straight wheel on entry; any late steering correction over the compression will snap the rear loose — this is where the softer rear ARB and wing trim pay off.
• Les Combes: late, hard brake from Kemmel Straight — use the front aero and brake bias to rotate the car early into the first apex, sacrifice nothing on exit traction for Rivage.
• Pouhon: carries massive speed — trust the front end, this corner rewards the camber/alignment setup more than any other on track; a lifted or lazy entry costs 2–3 tenths alone.
• Stavelot/Blanchimont: both near-flat — the softened rear ARB must still hold the car planted here; if it steps out, dial rear ARB back up 2500–5000 N/m rather than losing wing.
• Bus Stop: late aggressive kerb use is fine on this car's suspension travel — sacrifice a clean line for a tighter radius, the Z4 handles curb strikes well with this damper setup.

TYRES

• Slick (Soft compound for race deg management), Front 22.5 PSI cold / Rear 22.0 PSI cold, settling to ~27 PSI hot. No tyre blankets assumption — first lap treated as warm-up. Optimal operating window: 80–95°C, peak grip ~87°C.

ELECTRONICS

• TC: 3, ABS: 2, Engine Braking: 3 (medium, stability into Les Combes/La Source), Brake Bias: 56.5% front (adjustable in-cockpit, shift to 55.5% as fuel burns off and rears come in)

SUSPENSION

• // FRONT
• Ride Height: 60 mm
• Wheel Rate FL / FR: 145,000 N/m / 145,000 N/m
• ARB: 85,000 N/m
• Brake Torque Multiplier: 100%
• Brake Bias: 56.5%
• // REAR
• Ride Height: 65 mm
• Wheel Rate RL / RR: 130,000 N/m / 130,000 N/m
• ARB: 60,000 N/m
• Diff Preload: 70 Nm
• Diff Coast: 0.4
• Diff Power: 0.5

DAMPERS

AERO

• Front Splitter: 4, Rear Wing: 5 (reduced one step from max for lower drag on Kemmel/Blanchimont while retaining Eau Rouge stability), Brake Ducts Front: 4 / Rear: 3

KEY SETUP NOTE

• Rear wing at 5 (not max) with slightly stiffer rear ARB keeps the car planted through Eau Rouge/Raidillon compression and Blanchimont without sacrificing too much Kemmel top speed — front-end grip is deliberately prioritized via camber/pressure since front tyre temperature (not rear) is the long-run limiting factor on this car.

TRACK GUIDE

• La Source: brake late but straight-line only — trail brake minimally, this car understeers on entry if you ask for rotation and brake simultaneously; get the brake done, then rotate on throttle for the exit onto Kemmel.
• Eau Rouge/Raidillon: full commitment flat in this GT3 at race fuel if the car is stable — stay central, do not lift mid-compression, let the rear squat naturally; any snap here is terminal.
• Les Combes: this is where time is won — late, hard brake from 290+ km/h, car is stable under brakes if bias is correct; trail into the first apex, use the kerb aggressively on exit of the second part.
• Pouhon: commit early with a stable aero platform, trust the front end; a lifted or hesitant entry costs more than a slightly wide exit.
• Bus Stop: ride the inside kerbs hard on entry, the Z4 handles aggressive kerb strikes well with this damper setup; don't scrub too much speed — exit traction onto the pit straight matters for the whole lap.