BMW M340i (Gen 2 B58) Remapping and Tuning

Unlock the full potential of your BMW M340i (Gen 2 B58) with Onyx Performance, based in Slough, Berkshire, just outside West London. Whether you’re new to tuning or looking to extract the maximum performance from your G20/G21 M340i, we offer expert remapping, servicing, upgrades, and vehicle security solutions tailored specifically for your B58-powered BMW.

Our bespoke tuning packages are designed to increase power, enhance throttle response, and improve overall drivability, while maintaining the renowned reliability of the Gen 2 B58 engine.
Visit our shop to find tuning packages.

BMW M340i (Gen 2 B58) Stage 1 & Stage 2 – Power Gains

Stage 1 – Power Gains:

• Stock Power: 374HP / 500Nm
• Stage 1 Remap: 440HP / 620Nm
• Hardware Required: None

Our Stage 1 remap provides instant power and torque gains without requiring any hardware modifications. The optimised ECU calibration enhances throttle response, gear shifts, and turbo efficiency, while ensuring the smooth and reliable operation of your B58 engine.

Stage 2 – Power Gains:

• Stock Power: 374HP / 500Nm
• Stage 2 Remap: Up to 480HP / 700Nm
• Hardware Required:
  • Decat Downpipe or High-Flow Sports Catalyst
  • Upgraded Air Intake System
  • Onyx Stage 2 Gearbox Software (Highly Recommended for Automatic Models)
  • Spark Plug and Ignition Coil Upgrade (Recommended for Stage 2 tuning to ensure optimal ignition and reliability under increased boost pressure)

Stage 2 builds on Stage 1 with essential hardware upgrades to improve airflow, cooling, and turbo efficiency, unlocking even greater power and sharper throttle response.

Looking for Even More Power?

For enthusiasts seeking maximum performance, we offer Stage 3 tuning packages featuring hybrid turbo upgrades, high-pressure fuel pumps, and supporting modifications for even greater power and torque.

📞 Call us on 01753 439321 to discuss Stage 3 options!

Why Choose Onyx Performance?

At Onyx Performance, we specialise in BMW M340i (Gen 2 B58) tuning and provide a range of services to ensure your BMW operates at peak performance while maintaining reliability:

✔ Rolling Road (Dyno) Testing for precise power measurement
✔ Data Logging and Diagnostics to ensure optimal engine performance
✔ Before and After Performance Printouts
✔ Engine Smoke Tests to check for Boost/Vacuum Leaks
✔ Optional Features: Overrun Crackles, Speed Limiter Removal, and Catalyst Fault Code Deletes

Our expert team ensures your BMW M340i G20/G21 delivers improved power, torque, and response, while maintaining engine safety as a priority.

Exhaust Upgrades for BMW M340i (Gen 2 B58)

Enhance the sound and performance of your M340i with a high-performance exhaust system:

🔥 Decat Downpipes – Improves turbo efficiency and exhaust flow for maximum power
🔥 High-Flow Sports Catalysts – Reduces backpressure while remaining emissions compliant
🔥 Cat-Back Exhaust Systems – Enhances exhaust tone and sound quality
🔥 Resonator Deletes – Adds a sportier, aggressive exhaust note

Pairing Stage 2 tuning with a decat downpipe or high-flow sports catalyst allows for maximum power gains and an enhanced exhaust note.

Servicing and Maintenance for BMW M340i (Gen 2 B58)

Keeping your BMW M340i (Gen 2 B58) in peak condition is essential for long-term reliability. At Onyx Performance, we offer:

🔧 Routine Servicing: Oil changes, filter replacements, and essential inspections
🔧 Brake Repairs and Upgrades: OEM replacements and performance brake kits
🔧 Suspension Maintenance: Checks and optimisations for handling and ride comfort
🔧 Diagnostics and Fault Repairs: Advanced system scans to prevent potential issues

With our expertise in BMW B58-powered models, you can trust Onyx Performance to maintain and enhance your vehicle with precision and care.

Styling, Performance Upgrades & Vehicle Security

Elevate your BMW M340i (Gen 2 B58) with custom styling, performance upgrades, and vehicle security solutions tailored to your needs:

Styling and Performance Upgrades:

🏁 Aero Kits & Carbon Fibre Components – Aggressive styling and improved aerodynamics
🏁 Lowering Springs & Coilovers – Enhanced handling and stance
🏁 Big Brake Kits – Superior stopping power for track and road use

Vehicle Security Solutions:

Protect your BMW M340i (Gen 2 B58) with state-of-the-art security solutions, ensuring peace of mind:

🔒 Autowatch Ghost Immobilisers – Prevents key cloning and unauthorised starts
🔒 MetaTrak Trackers – Live GPS tracking with mobile app integration
🔒 Scorpion Track Systems – Motion alerts and driver recognition for ultimate protection
🔒 Fleet Trackers – Ideal for multiple high-value vehicles with monitoring features

Our security systems are professionally installed to provide seamless integration and maximum protection.

What Our Customers Say

⭐ “Stage 1 completely transformed my M340i! It’s quicker, smoother, and more responsive. Fantastic service from Onyx Performance!”
– Nathan B., London

⭐ “Stage 2 tuning with the decat downpipe and gearbox software took my M340i to a whole new level. The power delivery and exhaust sound are incredible!”
– Arjun K., Birmingham

Opening Hours and Contact Information

📍 Visit Us:

• Location: Slough, Berkshire
• Opening Hours:
  Monday–Friday: 10 AM–6 PM
  Saturday: 10 AM–3 PM
  Closed Sundays
• 📞 Phone: 01753 439321
• 📧 Email: info@onyxperformance.co.uk

About Onyx Performance

At Onyx Performance, we specialise in high-quality tuning, remapping, servicing, upgrades, and security solutions for BMW M340i (Gen 2 B58), ensuring maximum performance, reliability, and safety.

Our experienced team is committed to providing the best tuning solutions in the UK for high-performance BMWs.

Flexible Finance Options

💳 Spread the cost of your BMW M340i tuning, performance upgrades, and security solutions with our flexible finance plans, available over 4 monthly payments.

✅ All prices include VAT
✅ No hidden fees
✅ Simple application process

Contact Onyx Performance

Transform your BMW M340i (Gen 2 B58) today with Onyx Performance. Whether you’re looking for Stage 1 or Stage 2 remapping, performance exhaust systems, styling enhancements, or vehicle security solutions, our expert team is here to help.

📞 Call us now on 01753 439321 to book your tuning service or discuss Stage 2 and security options!