Understanding the McLaren 720S

The McLaren 720S, introduced in 2017 as the successor to the 650S, represents a quantum leap in supercar performance. At its heart lies the M840T engine: a 4.0-liter twin-turbocharged V8 that delivers 710 horsepower and 568 lb-ft of torque from the factory. This powerplant is mated to a seven-speed seamless-shift gearbox that sends power exclusively to the rear wheels. The car’s carbon-fiber MonoCage II chassis keeps curb weight at just 2,815 pounds, resulting in a power-to-weight ratio that rivals far more expensive hypercars.

Yet for track-day veterans and amateur racers, stock performance is rarely enough. The 720S’s engine management system is notoriously conservative, leaving significant headroom for tuning. With the correct road course setup—optimizing not just the engine but also the vehicle’s chassis and aerodynamics—owners can extract an additional 50 horsepower at the wheels. This increase transforms an already blistering machine into a true track weapon, shaving seconds off lap times while maintaining reliability.

Key Components of a Road Course Setup

A proper road course setup for the 720S involves more than a simple software flash. It requires a holistic approach that balances power delivery, cornering grip, braking stability, and thermal management. Below we examine the five most impactful modifications that contribute to the coveted 50 hp gain.

Suspension Tuning

The 720S employs a double-wishbone front and multi-link rear suspension system with adaptive dampers. For sustained track use, the standard absorber tuning is optimized for compliance rather than high-frequency response. Recalibrating the damper curves using McLaren’s own Proactive Chassis Control II software can reduce body roll and improve transient response. Many aftermarket specialists offer reflashed ECU maps for the damping control module that provide firmer compression and rebound settings without sacrificing steering feedback.

Additionally, upgrading to adjustable coilovers from trusted brands such as Öhlins or KW Suspensions allows for precise ride-height and corner-weight adjustment. Lowering the center of gravity by 10–15 millimeters improves aerodynamic efficiency and reduces weight transfer during braking and acceleration. A properly corner-weighted 720S will exhibit more balanced tire wear and predictable handling at the limit.

Weight Distribution and Reduction

Stock 720S models have a static weight distribution of approximately 42% front / 58% rear. Moving the battery to the rear luggage area, replacing the heavy factory seats with carbon fiber race seats, and swapping the titanium exhaust for a lighter aftermarket unit can shift the balance to 40/60 or even 39/61. This rearward bias enhances traction out of turns, especially under power.

Weight reduction also directly benefits braking and tire longevity. Every 100 pounds removed yields roughly 1% improvement in acceleration and braking distances. Consider replacing the factory glass windows with Lexan polycarbonate, removing sound deadening, and installing lightweight forged alloy wheels. Companies like McLaren offer carbon ceramic brakes as standard, but upgrading to a larger rotor package with six-piston calipers provides fade-free stopping power.

Tire Selection

No power increase matters if the tires cannot transmit it to the pavement. The McLaren 720S leaves the factory on Pirelli P Zero tires, but for road course use, switching to a semi-slick compound is essential. The Pirelli P Zero Trofeo R or Michelin Pilot Sport Cup 2 R offer significantly more lateral grip and higher temperature tolerance. These tires feature a softer rubber compound and a tread pattern optimized for dry track conditions.

Proper tire pressures also play a critical role. Starting pressures around 30 psi cold for the front and 28 psi cold for the rear work well on most circuits. Monitoring tire temperatures with a pyrometer after hot laps allows fine-tuning of camber alignment to ensure an even contact patch. A well-chosen tire set can reduce lap times by 2–3 seconds on a typical 2-mile circuit.

Engine Mapping and ECU Tuning

The single largest contributor to a 50 horsepower increase is a refined engine control unit (ECU) calibration. The M840T engine uses a Bosch MED17.1 ECU that manages boost pressure, fuel injection timing, ignition advance, and variable valve timing. Factory boost levels rarely exceed 14 psi, but the engine internals (forged connecting rods, cast aluminum pistons) can safely handle up to 20 psi with proper fuel and cooling.

Aftermarket tuners such as Riley Motorsports, VF Engineering, and MAST Performance offer custom ECU maps tailored to specific octane ratings. A Stage 1 tune on 93-octane fuel typically yields 30–40 wheel horsepower, while a Stage 2 tune with supporting mods (downpipes, intercooler) pushes gains to 50–60 hp. The key is optimizing the fuel-air ratio to avoid detonation. Many tuners also adjust throttle response maps to eliminate the factory’s artificial torque limitation in first and second gears.

For those wishing to monitor engine parameters in real time, a datalogger or piggyback system (like the Syvecs S6+) provides unlimited control over boost curves and ignition timing. However, all ECU modifications should be performed by specialists familiar with the McLaren CAN bus architecture to avoid triggering error codes or limp modes.

Exhaust System Upgrades

Reducing back pressure in the exhaust system is essential for higher engine output. The factory exhaust features restrictive catalytic converters and a resonator that dampens sound but impedes flow. Replacing the downpipes with 200-cell high-flow catalytic converters or full cat-less downpipes reduces restriction and can lower exhaust gas temperatures (EGT). Aftermarket cat-back systems from Capristo, Armytrix, or Akrapovic often use larger diameter tubing (2.75 inches vs. stock 2.5 inches) and reduce weight by 10–15 pounds.

A full exhaust upgrade combined with a Stage 2 tune accounts for approximately 15–20 horsepower of the total 50 hp gain. The improved scavenging effect also helps spool the turbos more quickly, improving throttle response out of slow corners. Additionally, many aftermarket exhausts offer valve control systems that allow the driver to switch between a quieter mode for street use and an open mode for maximum performance on track.

Benefits of a 50 HP Increase

A 50 wheel-horsepower gain in a car that already produces over 600 at the wheels translates into tangible track improvements. On straights, the 720S will accelerate from 60–130 mph approximately 0.6 seconds faster. Corner exit speeds increase by 3–5 mph because the driver can get on the power earlier without overwhelming the rear tires. Lap time reductions of 1.5 to 2 seconds are typical on medium-length circuits.

Other benefits include improved throttle response and a broader torque curve. The tuned engine delivers peak torque earlier in the rev range (around 3,500 rpm vs. stock 4,500 rpm), making it easier to maintain momentum through slower sections. This also boosts driver confidence, as the car feels more urgent and predictable when exiting corners.

The Science Behind the 50 HP Gain

To understand how each modification contributes, consider the engine’s air and fuel flow. The M840T’s twin turbochargers are capable of 22 psi, but the factory restricts them to 14 psi for emissions and durability reasons. A Stage 1 tune raises boost to 17 psi, which alone adds roughly 35 horsepower. High-flow downpipes reduce exhaust back pressure by 40%, allowing the turbochargers to spool faster and maintain higher boost levels at higher engine speeds. This yields another 10–15 hp. Finally, a performance intercooler (or upgraded charge air cooler) reduces intake air temperatures by 20–30 degrees Fahrenheit, increasing air density and protecting against heat soak during long sessions. Together, these enhancements produce the advertised 50 horsepower increase without any internal engine modifications.

Implementation Steps and Choosing a Tuner

Before modifying your 720S, establish a baseline with a dyno run and a track day to log performance metrics. Research tuners who specialize in McLaren vehicles, as generic BMW or Porsche software can damage the unique electronics. Look for shops with proven results, including before-and-after dyno sheets and customer reviews. A reputable tuner will provide a custom calibration tailored to your specific vehicle, rather than a one-size-fits-all file.

Most McLaren tuning specialists recommend the following order: perform suspension and tire upgrades first to maximize grip, then install exhaust modifications, and finally flash the ECU. This sequence ensures the car’s cooling and traction systems are prepared to handle the extra power. Always use 93-octane or higher fuel; for track days, consider blending with unleaded race gas or using an octane booster to prevent knock.

External resources such as 1013MM offer comprehensive McLaren performance packages that include dyno tuning, suspension calibration, and data-logging support. For tire recommendations, consult the Michelin or Pirelli websites for track compound options.

Safety and Reliability Considerations

While the 720S is robust, adding 50 wheel horsepower does place additional stress on the drivetrain. The seven-speed gearbox is built to handle around 800 lb-ft of torque, so a tuned car operating at 650–680 lb-ft is within limits. However, frequent hard launches and full-throttle upshifts can accelerate clutch wear. Consider adding an upgraded transmission cooler if you plan multiple track days per month.

Cooling system upgrades are highly recommended. The factory engine oil cooler and intercooler are adequate for street driving but can reach thermal saturation after 15 minutes of sustained aggression. An additional auxiliary radiator, larger intercooler core, or water-methanol injection system can keep intake temperatures in check. Monitor coolant and oil temperatures with an aftermarket gauge or using the car’s built-in telemetry system. If temperatures exceed 230°F oil or 210°F coolant, back off the pace to allow cooling.

Finally, ensure your tires and brakes are in excellent condition before each event. A 50 hp increase means faster corner entry and exit speeds, placing greater demands on the stopping system. Upgraded brake pads (such as Pagid RS-29) and high-temperature brake fluid (motul RBF 660) are inexpensive insurance that pays dividends in consistency and safety.

Conclusion

Extracting 50 extra horsepower from a McLaren 720S for road course use is not only possible but also practical with a properly balanced package of suspension tuning, weight reduction, tire selection, ECU calibration, and exhaust upgrades. Each modification works synergistically to improve lap times, throttle response, and driver confidence. By focusing on a systematic approach and working with experienced McLaren specialists, owners can unlock the full potential of their supercar while maintaining reliability. The result is a machine that feels even more alive on the circuit—a worthy investment for those who live for the racing line.