Porsche 911 GT2 RS Tuning Guide — Best Setup for FH6

Tuning Parameters & Reasoning

Tire Pressure — 32.5 PSI Front / 31.5 PSI Rear

The GT2 RS carries 1470kg with a roughly 39/61 weight distribution — that's over 890kg sitting on the rear axle at rest, and significantly more under acceleration. The rear tires are doing double duty: they're handling the weight, the power, AND the lateral grip, which means they generate enormous heat. The 31.5 PSI rear pressure is slightly lower than the front to maximize the contact patch under combined loading — when you're cornering AND accelerating simultaneously (which is basically every corner exit in this car), the rear tires need every square millimeter of rubber touching pavement. The 32.5 front pressure keeps the front tires responsive for turn-in without understeering. On hot tracks, monitor rear tire temps — if they're hitting orange after two laps, drop to 31.0 rear and add a cooling lap between push laps.

Final Drive — 3.50

The GT2 RS's seven-speed PDK has short lower gears and a tall seventh — you'll rarely use seventh on any circuit except maybe the Mulsanne Straight. A 3.50 final drive (slightly shorter than stock) keeps second through fifth in the meat of the powerband where the twin turbos are fully spooled. The flat-six makes peak torque from 2500 to 4500 RPM and peak power at 7000 — that's a narrow effective range for a 700hp engine. The 3.50 ensures you're landing in that 4500-7000 window after every upshift. Any shorter and first gear becomes unusable (you'll just spin), any taller and you're falling out of boost on technical sections. The PDK shifts fast enough that the slightly increased shift frequency isn't a time penalty.

Camber — -2.8 Front / -2.4 Rear

Rear-engine cars need more front camber than you'd expect because the light front end doesn't naturally load the outside tire as aggressively as a front-engine car. -2.8 degrees up front is aggressive but necessary — at S2 grip levels, the strut front suspension loses camber under compression, and without this much static negative camber the outside front tire rolls onto its shoulder mid-corner. The rear at -2.4 is also aggressive, but the 911's rear multilink has a better camber curve than the front struts, so slightly less static camber is needed. The key insight with 911 camber: you're using it to control understeer on corner entry (where the light front end wants to push) and oversteer on corner exit (where the heavy rear wants to step out). These numbers balance both phases.

Anti-Roll Bars — 34 Front / 32 Rear

The 911's rear weight bias means the rear naturally wants to roll more than the front — physics doesn't care about your lap times. The 34mm front bar fights the understeer that would otherwise dominate corner entry by keeping the front chassis flat and loading the outside tire properly. The 32mm rear bar is stiff enough to control body motion without making the inside rear lift — when that inside rear lifts on a 911, you lose all the mechanical grip that the rear-engine layout provides, and the car transitions from planted to spinning faster than you can countersteer. The 2mm stagger here is actually larger than it looks on paper because the rear bar is fighting against 60% of the car's weight. If the car feels pushy on entry, add 1mm to the rear bar before touching front camber.

Springs — 800 lb/in Front / 760 lb/in Rear

At 1470kg the GT2 RS isn't the lightest S2 car, and the rear weight bias means the rear springs need to be substantial. The 800/760 split with a front bias is deliberate: you need the front stiff enough to resist dive under braking (the front end is light and dives easily, which unweights the rear and triggers the pendulum effect), and the rear stiff enough to control squat without being so stiff that it skips over bumps. The relatively small 40 lb/in split reflects the fact that spring rate isn't the primary tool for managing the 911's weight distribution — that's what the anti-roll bars and damping are for. On circuits with heavy curbing (think city street circuits), drop both ends by 50 lb/in for compliance.

Damping — Rebound 9.5/9.0, Bump 6.0/5.5

The GT2 RS has a lot of mass to control, and the rear-engine layout means that mass has leverage over the chassis. High rebound damping is essential to stop the car from oscillating after every input — in a 911, a single bump can trigger a weight transfer cycle that takes multiple oscillations to settle, and each oscillation is a moment where the rear tires are loading and unloading unpredictably. The 0.5 stagger favors front control because the front end's job is to point the car — if the front oscillates, your steering inputs are fighting chassis movement instead of directing it. The bump settings are moderate because the GT2 RS already has stiff springs — too much bump and it'll skate instead of gripping. If the car feels floaty over crests (a classic 911 problem), add 1.0 to front rebound and test again.

Aerodynamics — 90% Rear Wing

The GT2 RS's rear wing isn't decorative — at 90% setting it's generating real downforce that counteracts the rear-engine car's natural tendency to lift at high speed. The 90% (not 100%) setting is intentional: at max downforce the aero balance shifts too far rearward and you get high-speed understeer as the front end goes light. At 90% the front-to-rear aero balance stays neutral through the speed range. The front splitter should be matched to provide balanced downforce. For pure top-speed runs (highway racing, drag strips) drop the wing to 50%, but understand that above 280 km/h the rear end will feel light and sketchy — that's the 911's natural aerodynamic lift showing through.

Brakes — 50% Bias / 120% Pressure

This is the single most important setting on the GT2 RS, and the one that most people get wrong. The rear-engine layout means there's enormous weight over the rear axle, and under hard braking that weight distribution shifts closer to 50/50. Running the typical 60% front bias means you're massively underusing the rear tires' braking capacity — the rear brakes are just along for the ride while the fronts do all the work. Shifting to 50% bias makes the rear tires contribute meaningfully to deceleration, which shortens braking distances and — crucially — stabilizes the car under braking. A 911 that's braking only with the front tires is an unstable 911. 120% pressure gives you consistent pedal feel and enough clamping force for repeated heavy stops. In wet conditions, bring the bias back to 54% front — the reduced grip means the weight transfer under braking is less dramatic.

Differential — Accel 75% / Decel 50%

The GT2 RS needs aggressive differential settings because it's trying to put 700 turbocharged horsepower through two rear tires while carrying 60% of its weight over those same tires. The 75% accel lock ensures both rear tires work together on corner exit — without it, the inside rear lights up immediately and the car either spins or the traction control kills your exit speed. The 50% decel lock is higher than most cars because the 911's rear weight bias makes it naturally oversteer under trail braking — the locked rear axle resists the rotation, keeping the car stable when you're deep in the brake zone and turning in simultaneously. This is the stability secret for the Widowmaker: a locked diff on decel turns what would be snap oversteer into a controlled, predictable rotation. If you're drifting (and yes, rear-engine drifting is a unique kind of chaos), run 85/65 but understand the car will be a handful everywhere else.