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At Xatrix, we recently had the pleasure of working on one of BMW’s most exclusive modern M cars—the G80 M3 CS. With only a limited number produced worldwide, the M3 CS is already an incredible machine straight from the factory. However, for those seeking more performance, sound, and driving engagement, there’s always room for refinement!
The BMW G80 M3 CS is the lightest and most track-focused version of the M3 in its generation. It builds on the M3 Competition xDrive with a 40kg weight reduction, thanks to extensive use of carbon fibre across the roof, bonnet, front splitter, rear diffuser, and bucket seats. Under the bonnet, it houses the S58 3.0L twin-turbo inline-six, producing 543 BHP and 650Nm of torque, making it the most powerful M3 ever produced.
However, for our customer, the factory setup still had room for improvement—especially in terms of sound and power delivery. That’s where we stepped in.
The first stage of our tuning process involves unlocking the factory ECU to allow for advanced tuning. For this M3 CS:
For this build, the customer opted for our custom Stage 1 tune, which does not require additional hardware upgrades. Our Stage 1 tune safely increases power while keeping factory reliability intact.
One of the standout features of BootMod3 is switchable mapping, which allows the driver to change performance levels on the fly using the cruise control buttons. For this particular setup, we configured four unique map slots:
Additionally, we enabled Rolling Anti-Lag in Map 3, allowing for enhanced launch control and performance tuning.
Since this M3 CS had extremely low mileage, we decided to postpone dyno testing until the car has more miles on the clock. Instead, we:
At Xatrix, we take precision tuning seriously. While we currently use an off-site 4WD hub dyno, we plan to bring our own dyno in-house by early next year to streamline our tuning process.
To complement the tune, we installed several high-performance components, ensuring maximum efficiency and power gains
The Akrapovic Evolution Line Titanium Exhaust System with Catted Downpipes was chosen for its exceptional weight reduction and optimised exhaust flow. Made from high-quality titanium, it not only enhances performance but also produces an aggressive yet refined exhaust note. The catted downpipes provide improved turbo spool while maintaining emissions compliance, making it a perfect balance between performance and practicality.
For the tuning process, Bootmod3 Flashing Software was utilised. This industry-leading BMW tuning software enables real-time map switching, rolling anti-lag, burble adjustments, and remote tuning capabilities, offering unmatched flexibility and control.
We meticulously selected and tested these products to deliver top-tier performance without compromising reliability.
With these upgrades, the M3 CS now produces approximately 675HP and 850Nm of torque, delivering an exhilarating experience on both road and track. The combination of reduced weight, improved power, and a more aggressive sound profile makes this one of the most thrilling G80 M3 CS builds we’ve worked on.
Thinking of enhancing your M3 CS? Check out the performance parts used in this build and start your own tuning journey today!
Have a project of your own that deserves the spotlight? We’d love to see it! Tag us on Instagram (@mlperformanceuk) or send us an email at info@mlperformance.co.uk, and your ride could be our next featured build!
