BMW M240i Stage 1 & Stage 2 ECU Remapping

BMW M240i Stage 1 & Stage 2 ECU Remapping – Power Upgrades in Slough

BMW M240i Stage 1 & Stage 2 ECU Remapping

The BMW M240i, powered by the incredible B58 3.0-litre turbocharged straight-six engine, is already a thrilling compact performance car. However, with Stage 1 and Stage 2 ECU remapping, we can unlock even more power, sharper throttle response, and stronger mid-range acceleration – transforming your M240i into a true driver’s machine. At our Slough workshop, we specialise in precision ECU tuning tailored specifically to your car’s setup and driving style.

Our Stage 1 ECU remap is perfect for a standard or lightly modified M240i, delivering impressive horsepower and torque gains without sacrificing reliability. The tuning also refines throttle control and turbo spool, making the car more responsive in all driving situations, from city cruising to track days.

For enthusiasts chasing maximum performance, our Stage 2 ECU upgrade combines our advanced remap with key hardware upgrades such as a high-flow downpipe, uprated intercooler, and performance intake. This setup allows the B58 engine to run cooler, breathe better, and maintain peak power output during sustained high-performance driving – perfect for those who want their M240i to deliver relentless pace on road or track.

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Why Choose Onyx Performance?

As Seen on Carwow

We’ve been proudly featured on Carwow – a testament to the quality, professionalism, and performance-focused results that set us apart. Watch our feature here to see us in action.

Expertise You Can Trust

With years of experience and deep technical knowledge, our team understands performance vehicles inside and out – from custom remaps to high-end servicing.

Advanced Workshop & Tools

We operate from a state-of-the-art facility in Slough, equipped with cutting-edge diagnostics, dyno testing, and industry-leading tools for accurate, high-quality work.

Tailored Solutions for Every Vehicle

We don’t believe in one-size-fits-all. Every car gets a bespoke approach, ensuring the best results whether it’s a remap, upgrade, or routine service.

Trusted Nationwide

Performance enthusiasts from across the UK come to Onyx because they know they’ll receive premium-quality workmanship, careful attention to detail, and honest advice.

Complete Care, All in One Place

From tuning and servicing to tyres, trackers, and immobilisers – we offer a full suite of services under one roof, all with a strong focus on safety, reliability, and top-tier customer support.

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Book Your BMW M240i Stage 1 or Stage 2 Tuning in Slough

Experience the full potential of your BMW M240i with our custom Stage 1 and Stage 2 ECU remapping. Using dyno-tested software and precision calibration, we deliver safe, reliable, and exciting performance gains. Book your appointment at our Slough workshop today and feel the difference.

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Why Choose Onyx Performance for Servicing?

Experts in Performance Cars

We know how to properly care for performance, modified, and luxury vehicles. Our team has the skills and experience to handle specialist requirements confidently.

Correct Service Schedules

Every service follows the exact schedule recommended by your vehicle’s manufacturer, helping maintain performance and protect your warranty.

Quality or OEM Parts

We only use high-quality aftermarket or original manufacturer parts, ensuring long-lasting reliability and top-level performance.

Full Vehicle Inspection

Our service goes beyond just changing oil. We inspect all key systems to keep your car safe, smooth, and road-ready.

Honest Advice, No Surprises

With transparent pricing and expert recommendations, you’ll always know what your car needs – no upselling, no hidden fees.

Fast, Trusted & Tracked

We offer quick turnaround, maintain service records, and send reminders – that’s why customers travel to us from across the UK.

Frequently Asked Questions

What gains can I expect from Stage 1?

Stage 1 tuning typically adds 50–70 bhp and a strong torque increase, making acceleration much quicker.

Do I need any hardware upgrades for Stage 1?

No – Stage 1 works perfectly with stock components, though high-octane fuel is recommended for best results.

What’s required for Stage 2?

Stage 2 requires performance parts such as a sports downpipe, larger intercooler, and upgraded intake.

Will tuning affect reliability?

When done correctly with supporting hardware, our ECU remaps are safe and maintain engine reliability.

Can you provide before/after dyno runs?

Yes – we offer dyno testing to prove real-world power and torque gains.

Is this tuning detectable by BMW?

Yes – performance tuning can be detected by dealer diagnostic tools, which may affect warranty status.

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