Unlocking the Full Potential of the G87 M2

The G87 M2 is already a standout in BMW’s performance lineup, delivering raw power and sharp handling straight from the factory. Yet for serious enthusiasts, the pursuit of more horsepower is never truly satisfied. With the right combination of parts and software, the G87 can gain over 100 wheel horsepower without sacrificing reliability or daily drivability. This article details how pairing an ESS Tuning engine calibration with an Akrapovic exhaust system creates one of the most effective and widely respected upgrade paths for this chassis.

The key lies in the synergy between optimized fueling and ignition timing through the ECU, combined with drastically improved exhaust flow that reduces backpressure. By stacking these two upgrades, owners can achieve power levels that rival far more expensive builds, all while retaining factory-like manners for street use.

The G87 M2: A Performance Foundation Built for More

Under the hood, the G87 M2 uses the S58 engine—a twin-turbocharged 3.0-liter inline-six that already pushes around 453 horsepower and 406 lb-ft of torque in stock form. BMW engineered this powerplant with forged internals, a closed-deck block, and dual VANOS variable valve timing, giving it substantial headroom for modification.

However, the factory calibration leaves significant performance on the table due to emissions regulations, fuel quality tolerances, and torque limitations in lower gears. The stock exhaust system also creates a notable bottleneck, especially in the downpipe and mid-pipe sections. Understanding these stock limitations is the first step toward building a properly balanced high-horsepower setup that can handle sustained track use or spirited back-road driving.

ESS Tuning: Precision Calibration for Maximum Output

ESS Tuning has been a trusted name in BMW engine management for decades, known for their meticulous dyno development and emphasis on safety margins. Their tuning solutions for the G87 M2 go far beyond simple boost increases.

How ESS Software Unlocks Horsepower

ESS engineers rewrite the ECU tables controlling boost pressure, fueling, ignition timing, throttle mapping, and vanos actuation. Specifically for the S58, their calibration adjusts the following key parameters:

  • Boost targeting – Raises peak boost while ensuring wastegate control remains stable and responsive.
  • Fuel injection timing – Optimizes DI (direct injection) strategies for higher flow injectors (stock ones have margin) to support increased air mass.
  • Torque request limits – Removes the factory torque limitations in low gears, allowing full engine output without electronic intervention.
  • Cooling system controls – Activates the electric cooling pump and fan earlier and more aggressively to manage heat soak in high-demand situations.

This approach typically yields 80-100 additional horsepower at the crank on pump fuel (93 octane), with significant gains in the mid-range where it matters most for daily driving and club racing. ESS also offers ethanol fuel maps for those seeking even more output with Flex Fuel kit compatibility.

Installation and Safety Features

ESS provides a handheld flash tool that connects to the OBDII port. The process takes about 15 minutes and is fully reversible. The tune includes comprehensive monitoring for knock, intake air temperature, and exhaust gas temperature. In the event of extreme conditions, the software will safely pull timing rather than risk engine damage.

Importantly, ESS tuning is designed to work with multiple exhaust configurations, but the real magic happens when you pair it with a free-flowing system like Akrapovic.

Akrapovic Exhaust Systems: Engineering That Breathes Performance

Akrapovic is a Slovenian exhaust manufacturer renowned for motorsports pedigree and titanium construction. Their exhaust systems for the G87 M2 are no exception, offering significant weight savings and measurable horsepower gains even without a tune.

Key Design Features of the Akrapovic Setup

  • Titanium and Inconel construction – Reduces weight by roughly 40-50% compared to the stock steel exhaust. The G87 M2 Akrapovic system saves approximately 15 kg (33 lbs) in total.
  • Larger diameter piping – Increases cross-section area, cutting backpressure and allowing the turbochargers to spool more efficiently.
  • Valve-controlled mufflers – Retain factory exhaust valve functionality, giving the driver control over volume and drone. In Comfort mode the car remains civilized; in Sport Plus it delivers a race-inspired soundtrack.
  • Optimized Y-pipe and downpipes – The system eliminates restrictive primary cats (if a sport cat or catless downpipe version is selected) while maintaining emission compliance with optional catalyst.

On a completely stock G87 M2, an Akrapovic exhaust alone can add 10-15 horsepower and 15-20 lb-ft of torque, especially in the upper RPM range. But the real benefit comes when it acts as a low-restriction channel for the increased exhaust flow generated by the ESS tune.

The Synergy of ESS + Akrapovic: Why the Combo Works So Well

A simple ECU tune on a stock exhaust will yield nice gains, but the stock downpipe and muffler will still create a bottleneck. Conversely, a free-flowing exhaust without revised fuel and boost maps cannot fully exploit the improved airflow. Only when both components are paired do they generate a multiplicative effect.

How the Components Complement Each Other

  • ESS tune raises boost and advances timing – This forces a larger volume of air through the engine, which must be expelled efficiently.
  • Akrapovic exhaust reduces backpressure – The S58 turbos can spin faster and maintain spool at lower RPM, reducing lag and increasing peak flow.
  • Combined result – On the dyno, the ESS + Akrapovic combo consistently produces over 120 wheel horsepower gains (measured at the tires) over a stock G87 M2. This equates roughly to a 27-30% increase in overall power.

In addition, the improved exhaust flow lowers exhaust gas temperatures (EGTs) during sustained high-load runs, which keeps the engine bay cooler and preserves oil integrity. This thermal benefit is often overlooked but critical for track-day reliability.

Step-by-Step Guide to Installing the ESS and Akrapovic Combo

While professional installation is recommended for the exhaust, the ESS tune can be performed by any competent owner. Below is a logical sequence for completing both upgrades.

Tools and Parts Required

  • ESS flash tool (included with tune purchase)
  • Akrapovic exhaust system (choose between sport cat or catless downpipe kits)
  • Standard socket set (10mm, 13mm, 18mm, E-sockets recommended)
  • Jack and jack stands or lift
  • Oxygen sensor socket
  • Torque wrench

Installation Steps

  1. Disconnect the battery – Always isolate the electrical system before working near exhaust components or ECU connections. Let the car cool completely.
  2. Install the Akrapovic exhaust – Begin at the downpipe section, removing the stock downpipes and replacing them with the Akrapovic units. Follow with the mid-pipe and rear muffler. Torque all clamps to spec (typically 25 Nm for titanium clamps). Reconnect oxygen sensors using provided adapters if needed.
  3. Perform a leak check – Start the engine briefly and listen for exhaust leaks at flange joints. Tighten as necessary.
  4. Upload the ESS tune – Connect the ESS flash tool to the OBDII port under the driver’s dashboard. Follow the on-screen prompts: read the current stock file (backup), then flash the Stage 1 or Stage 2 ESS calibration (Stage 2 is preferred with downpipe upgrade). The process takes roughly 12-15 minutes.
  5. Reconnect battery – Reconnect the negative terminal and let the car complete self-learn cycles (turn ignition on for 30 seconds, wait for warning lights to clear).
  6. Test drive and data log – Drive the car gently for 10 minutes to adapt fueling trims, then perform a few full-throttle pulls in 3rd and 4th gears. Monitor boost, fuel trims, and IATs. Using the ESS logging feature, check that no knock events appear.

Expected Performance Gains: Dyno Results and Real-World Numbers

We compiled data from several independent dyno runs on the G87 M2 with the ESS Stage 2 tune (using 93 octane) and the Akrapovic full titanium exhaust (with sport cats). The numbers below are representative averages.

Configuration Peak Horsepower (whp) Peak Torque (wtq)
Stock G87 M2 458 whp 440 wtq
ESS Stage 1 (stock exhaust) 525 whp 510 wtq
ESS Stage 2 + Akrapovic (sport cat) 585 whp 580 wtq

These numbers show a total gain of 127 wheel horsepower and 140 lb-ft of torque over stock. In practical driving, this translates to 0-60 mph times dropping from 3.9 seconds to roughly 3.2-3.3 seconds (using drag radials) and quarter-mile passes in the 10.8-second range at over 125 mph.

The torque curve is especially impressive: over 400 lb-ft is available from just 2500 RPM all the way to redline, making the car feel effortlessly fast in everyday traffic.

Real-World Driving Impressions

Numbers aside, the ESS/Akrapovic combination transforms the character of the G87 M2. The throttle response becomes razor-sharp, with no discernible lag from a standstill. The Akrapovic exhaust adds a deep, metallic note that builds into a howl above 6000 RPM, while still being comfortable for highway cruising thanks to the valve system.

On a closed course, the extra power is immediately felt exiting corners. The faster spool means the turbos are already making boost before the apex, allowing earlier and more aggressive throttle application. The weight savings from the titanium exhaust also improve turn-in response and reduce unsprung mass on the rear axle.

Maintenance and Long-Term Considerations

With a 127+ whp increase, certain supporting measures become wise. We strongly recommend the following:

  • Upgrade engine mounts – The increased torque can cause excessive engine movement, potentially damaging intercooler hoses. ESS and Akrapovic both suggest stiffer mounts for track use.
  • Monitor fuel system health – On very high-output setups (Stage 2+), consider installing a higher-flow low-pressure fuel pump (e.g., from Fuel-It) to maintain pressure at high RPM.
  • Oil cooling – The G87 M2 already has a solid oil cooler, but after multiple hot laps on a summer day, oil temperatures can climb. An aftermarket oil cooler upgrade is recommended if you plan sustained lapping.
  • Spark plugs – ESS recommends reducing the gap on the stock spark plugs by 0.3mm for boost levels above 20 psi. This prevents misfire at high load.
  • Regular data logging – Use the ESS logging capability to keep an eye on long-term fuel trims and knock. This simple step can catch issues before they become failures.

Conclusion: The Benchmark Combination for G87 M2 Performance

The ESS Tuning + Akrapovic exhaust combo is not just a popular choice among G87 M2 owners; it is arguably the most well-rounded, proven path to a legitimate 100+ wheel horsepower increase. The tune safely exploits the S58 engine’s considerable developmental overhead, while the Akrapovic system removes the physical roadblocks that would otherwise limit flow.

Whether you are looking for a more thrilling daily driver or a weapon for track days and autocross, this combination delivers on every front: power, reliability, sound, and weight savings. With proper installation and adherence to the supporting modifications outlined above, you can confidently drive a G87 M2 that rivals cars costing twice as much.

For further reading and to verify these claims, check the official pages of ESS Tuning and Akrapovic, or browse community feedback on the BimmerPost forum G87 M2 section.