Lamborghini Sian FKP 37 Tuning Guide — Best S2 Setup

Class Range: S2 | Base Horsepower: 819hp | Drivetrain: AWD | Weight: 1,595kg | Best Class: S2

The Sian is Lamborghini's first hybrid supercar — more precisely, the first production car to use a supercapacitor. Unlike the Revuelto with its true PHEV system and three motors, the Sian's hybrid setup is simple: a naturally-aspirated V12 making 785 hp plus a 48V electric motor making 34 hp, with the supercapacitor storing brake-recovered energy and releasing it under acceleration. 819 hp total. In FH6 the supercapacitor system is simplified — you don't feel the charge-discharge rhythm, and the electric assist feels like it's always on. That hides the real car's biggest point of debate (the supercapacitor's pros and cons), but it also turns the Sian into a pure, easy-to-drive AWD supercar in FH6.

With 1,595 kg, AWD and 819 hp, its power-to-weight ratio is close to the Countach's, but the chassis tuning is clearly sportier — the Sian's suspension is stiffer than the Countach's and the steering is quicker. In S2 you'll face the holy trinity of the P1, 918 and LaFerrari, and the Sian's tactic is to play to its strengths and hide its weaknesses: avoid high-speed corners (it can't match the P1's active aero), and win the low-to-medium-speed corner exits (AWD traction crushes RWD). Most S2 circuits have more low-to-medium-speed corners than high-speed ones, and the Sian turns that corner-exit edge into a real lap-time advantage in those sections.

On the tuning side, the Sian's biggest weakness is its front axle — 819 hp sounds scary, but the electric motor only contributes 34 hp, and there's no independent front-axle motor. So on turn-in the front wheels rely purely on mechanical grip, with no torque distribution helping out. Understeer is still an issue, just not as bad as the Countach (because the Sian is sportier overall). Fixing understeer is priority number one, followed by using the AWD advantage to maximize corner-exit acceleration.

Best Tuning Setup by Class

The stock 819 hp is enough for S2 — the Sian's strength isn't raw horsepower but corner-exit acceleration. If you're going to upgrade, do the suspension and tires first, and touch the engine last. The NA V12 is more reliable than a turbo, and the money spent on boost is better spent on weight reduction.

Tuning Parameters — The Details Matter

Tire Pressure

Front: 31.5 PSI, Rear: 30.5 PSI. The pressures run close to the Countach's — similar weight distribution (roughly 43:57 rear-biased) — but the Sian's stiffer suspension lets you run pressures slightly higher. Front 31.5 PSI guarantees front-axle steering response on turn-in, while rear 30.5 PSI works with the AWD to give a large rear contact patch on corner exit.

Gearing

Final Drive Ratio: 3.65 (S2). The Sian's 7-speed ISR gearbox is from the same family as the Countach/Aventador, with slower single-clutch shift logic. The gearing should exploit the V12's high-rev advantage — an 8,000+ RPM redline means you can run shorter ratios than a turbo car for better corner-exit acceleration without worrying about hitting the limiter. 3.65 gives the best low-speed corner-exit performance on S2 circuits, with a top speed around 350 km/h.

Alignment

Camber: Front -2.5, Rear -1.8. The front setting is as aggressive as the Countach's, for the same reason — understeer. Rear -1.8 is enough for the Sian because its rear suspension geometry is more advanced than the Countach's (rear-wheel steering helps). Toe: Front -0.1, Rear 0.1. Slight front toe-out speeds up turn-in, rear positive toe stabilizes. Caster: 7.5.

Anti-Roll Bars

Front: 33.0, Rear: 30.0. The Sian's body control is better than the Countach's, but the bars still need to run stiff. Front 33 is the main weapon against understeer — a stiff front bar limits outer front wheel compression, preserves negative camber, and boosts front-axle grip on entry. Rear 30 can't be too soft, otherwise under acceleration the rearward weight shift lifts the inside rear wheel off the ground.

Springs

Front: 750 lb/in, Rear: 680 lb/in. The Sian's suspension geometry suits stiffer springs — the pushrod suspension's motion ratio makes these numbers reasonable at the wheel. Front 750 supports the front-axle load under heavy braking, while rear 680 runs slightly softer so the rear wheels have travel to absorb road imperfections under acceleration. Ride height: lower by 0.8 inch.

Damping

Rebound: Front 8.5, Rear 7.8. Bump: Front 5.5, Rear 4.8. The Sian's damper tuning is sporty from the factory — rebound needs to be high enough to control the body's dynamic movement (nose dive under braking, squat under acceleration), while bump shouldn't be too aggressive or the tires hop over rough sections. If you run Guanajuato or other extremely uneven circuits, drop front and rear bump by 0.8 each.

Aero

Forza front splitter (cornering bias), rear wing downforce at 70%. The Sian's factory aero borrows the Countach's wedge shape with modern aerodynamics, but in FH6 the stock downforce isn't enough. Rear downforce at 70% delivers a clear tail-stability gain through high-speed corners (200 km/h+). The Sian's top speed is high anyway, and 70% downforce costs about 6-8 km/h of top speed — totally worth it.

Brakes

Balance: 55% Front, Pressure: 108%. The Sian is nearly 200 kg lighter than the Revuelto, so the brake pressure doesn't need to be as aggressive. 55% front balance keeps the tail from wandering under hard braking (the rear wheels also carry a fair share of braking load because of the rearward weight). 108% pressure gives enough initial bite without triggering the ABS constantly.

Differential

Center diff: 60% rear bias. Front diff: Accel Lock 35%, Decel Lock 15%. Rear diff: Accel Lock 65%, Decel Lock 35%. The core difference from the Countach is the more rear-biased center diff (60% vs 55%) — the Sian's chassis is more willing to rotate, and the 60% rear bias makes it feel more like a RWD car on turn-in. The front diff lock runs slightly higher than the Countach's because the Sian has no front-axle motor to distribute torque, so it needs mechanical lockup to guarantee front-axle traction on corner exit.

Best Race Types

Low-to-medium-speed S2 road circuits are the Sian's strongest territory — the more low-speed corners a technical track has, the more obvious the Sian's AWD corner-exit advantage becomes. Highway races are runnable but the strength doesn't show — fighting for top speed on long straights isn't the Sian's game. In the rain it's unbeatable — AWD corner-exit traction crushes every RWD rival in the wet, and a wet race is prime Sian lap-setting time. Skip off-road. Drag racing is worth a shot — the AWD launch makes 0-100 and the 1/4 mile quick, but top speed can't match a top-speed monster like the Jesko.

Tuning Share Codes

The Sian's community in FH6 is more active than the Countach's — it's Lamborghini's first hybrid flagship, after all, and it carries that status. Drop your Sian tune codes below, especially any S2 setup that consistently lands at the front of the lap charts. I'm particularly interested in wet-weather Sian tunes — the AWD's rain potential still feels underexplored.

Common Tuning Mistakes

Assuming the supercapacitor system has special gameplay in FH6. FH6 simplifies the Sian's hybrid system — you don't manage the supercapacitor, it's just always on. Don't waste time strategizing capacitor cycles; put that energy into the chassis.

Over-prioritizing weight reduction and ignoring aero. The Sian's 1,595 kg isn't light but it isn't heavy either. The first weight-reduction stage is useful, but the second stage's PI return drops off a cliff. The same PI spent on the aero kit delivers a far more obvious high-speed-corner lap-time gain than dropping another 30 kg.

Running stock tires in S2 races. The Sian's factory P Zero street tires are nowhere near enough for S2-class roads — semi-slicks are the bare minimum.

Center diff too front-biased. Some people think AWD should be front-biased for stability — the Sian just becomes the king of understeer. 60% rear bias is the floor; 65% is also worth trying.

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