Porsche 917K

• Note: the Porsche 917K is a late-1960s/early-1970s endurance prototype — a historic, mechanically simple car with no electronic aids, no ABS, no TC, no diff adjustability beyond a basic mechanical LSD, and fixed-rate springs with limited setup scope in AC. Values below reflect that reality rather than a modern GT3 car.

TYRES

• Compound: Historic Slick (only option)
• Front: 21.0 PSI cold (target hot ~26 PSI)
• Rear: 21.0 PSI cold (target hot ~26 PSI)
• No tyre blankets available for this era car — expect a genuine cold out-lap; build heat gradually for 2-3 laps before pushing.

ELECTRONICS

• TC: None fitted
• ABS: None fitted
• Engine braking: Fixed (no adjustment)
• Brake bias: Adjustable mechanically — see below

SUSPENSION

• // FRONT
• Ride Height: 95 mm
• Wheel Rate FL / FR: 58000 N/m / 58000 N/m
• ARB: 12000 N/m
• Brake Torque Multiplier: 100%
• Brake Bias: 54%
• // REAR
• Ride Height: 100 mm
• Wheel Rate RL / RR: 62000 N/m / 62000 N/m
• ARB: 8000 N/m
• Diff Preload: 60 Nm
• Diff Coast: 0.4
• Diff Power: 0.3

DAMPERS

AERO

• Front wing: fixed (no adjustment, low-drag long-tail style body)
• Rear wing: 2 (mid setting, balances Zolder's medium-speed corners against the long back straight)
• Downforce level: Low-Medium — this car relies on mechanical grip and ride height more than wing angle
• Brake ducts: N/A (not modeled on this car)

KEY SETUP NOTE

• The 917K has a notoriously nervous rear end at high speed due to its rearward weight bias and era-correct aero — at Zolder's fast Butte kink and the run toward the final chicane, any mid-corner lift or aggressive trail-braking rotation can snap into oversteer with little warning; keep rear ride height slightly higher than front and favor a touch more rear ARB stiffness than instinct suggests to tame this, sacrificing a little rotation for predictability under braking.

TRACK GUIDE

• Turn 1 (Terlamenbocht): Late braking rewards here, but the 917K's long wheelbase means you must brake in a straight line — any trail-braking rotation attempt on the slicks will snap the rear loose; brake earlier than you think, turn in clean.
• Sector 2 esses: This is where lap time is won — carry momentum through the direction changes smoothly; sudden steering inputs unsettle the rear-engined weight transfer badly.
• Butte (fast kink before the back straight): Flat in top gear if committed