BMW 840i Remapping and Tuning
Upgrade your BMW 840i 340HP with professional Stage 1 and Stage 2 ECU tuning from Onyx Performance in Slough, Berkshire.
The BMW 840i G14/G15/G16 features a 3.0-litre B58 turbocharged petrol engine, delivering smooth power, strong torque and refined grand-touring performance. Our bespoke ECU remapping is designed to unlock additional performance while maintaining the balance of power, drivability and everyday comfort expected from your BMW 8 Series.
Whether you drive the 8 Series Convertible (G14), Coupé (G15) or Gran Coupé (G16), our tuning solutions can enhance acceleration, throttle response and mid-range pulling power.
BMW 840i Performance Figures
Standard Performance
- Power: 340HP
- Torque: 500Nm
Stage 1 Remap
- Power: 430HP
- Torque: 620Nm
- Price: £499.00
Stage 2 Remap
- Power: 470HP
- Torque: 680Nm
- Price: Call for a Stage 2 quote
Performance figures are indicative and may vary depending on vehicle condition, fuel quality, software version and supporting modifications. Final results are subject to vehicle-specific assessment.
Gearbox Tuning
Enhance the driving experience of your BMW 840i with professional gearbox tuning. Depending on the transmission fitted, gearbox calibration can improve shift response, shift timing and torque management for a more responsive and refined drive.
Available options:
- Stage 1 Gearbox Remap: Contact for Price
- Stage 2 Gearbox Remap: Contact for Price
- Stage 3 Gearbox Remap: Contact for Price
Contact our team to confirm gearbox compatibility and the most suitable calibration for your vehicle.
BEFORE TUNING
Before remapping, we recommend ensuring your BMW 840i is in good mechanical condition. Any existing engine warning lights, diagnostic faults, boost leaks or maintenance issues should be investigated before tuning.
Our team can discuss your vehicle’s condition, intended use and performance goals before recommending a suitable remap.
SERVICING AND MAINTENANCE
Regular servicing is essential for maintaining performance and reliability. We recommend keeping engine oil, filters, spark plugs and other service items up to date in line with BMW’s requirements and your vehicle’s usage.
A well-maintained engine provides a better foundation for performance tuning.
EXHAUST UPGRADES
Enhance the sound and character of your BMW 840i with suitable exhaust upgrades. Depending on your chosen setup, options may include upgraded exhaust components and performance-oriented systems.
All exhaust modifications should comply with applicable road-use, emissions and noise regulations.
PERFORMANCE UPGRADES
Complement your BMW 840i remap with carefully selected supporting upgrades. Depending on your performance goals, these may include:
- Upgraded intake components
- Improved charge-air cooling
- Turbocharger and boost-system upgrades
- Supporting hardware for higher-stage tuning
Stage 2 performance typically depends on suitable supporting modifications. We can advise on compatibility and requirements before work begins.
STYLING AND BODY UPGRADES
Personalise your BMW 8 Series with styling enhancements designed to complement its distinctive appearance. Available options may include exterior styling components, wheel upgrades and other appearance modifications, subject to model and fitment compatibility.
VEHICLE SECURITY
Protect your BMW with suitable vehicle security solutions. Contact Onyx Performance to discuss available security enhancements and options compatible with your vehicle.
WHY CHOOSE ONYX PERFORMANCE?
At Onyx Performance, we provide performance tuning solutions tailored to your vehicle and driving requirements.
- Professional ECU remapping for improved power and torque
- Stage 1 and Stage 2 tuning options
- Advice on supporting hardware and gearbox tuning
- Performance upgrades and styling options
- A dedicated team based in Slough, Berkshire
Our aim is to deliver a responsive, enjoyable driving experience with a tuning package suited to your BMW 840i.
REMAPPING IN SLOUGH
Onyx Performance provides BMW remapping and tuning in Slough, Berkshire. Whether you own a BMW 840i Convertible, Coupé or Gran Coupé, contact our team to discuss the available tuning options, vehicle compatibility and expected performance improvements.
Frequently Asked Questions
How much power can a BMW 840i gain from a Stage 1 remap?
The supplied indicative figures increase power from 340HP to approximately 430HP, with torque rising from 500Nm to around 620Nm. Actual results depend on vehicle condition, fuel and software compatibility.
How much power can a BMW 840i gain from a Stage 2 remap?
The supplied indicative figures are up to 470HP and 680Nm. Stage 2 tuning may require supporting hardware, and the exact requirements should be confirmed for your vehicle. Contact us for a Stage 2 quote.
Does my BMW 840i need hardware upgrades?
Stage 1 tuning may be suitable for a standard, healthy vehicle. Stage 2 commonly requires supporting modifications, depending on the calibration and hardware fitted. We will advise on the requirements for your setup.
Can I have the gearbox remapped?
Gearbox tuning may be available depending on the transmission and control unit fitted. Contact our team to confirm compatibility and pricing.
Do you offer dyno sessions?
Yes. Dyno sessions are available for £120.00. Contact us to discuss availability and whether a dyno session is suitable for your vehicle.
Is Stage 3 tuning available for the BMW 840i?
More extensive tuning may be possible with suitable hardware and a vehicle-specific assessment. Stage 3 requirements and pricing depend on the intended power target and supporting modifications.
Does my BMW 840i require an ECU unlock?
ECU access requirements can vary with model year, ECU hardware and software version. Your vehicle should be assessed to confirm the appropriate tuning method before booking.
BOOK YOUR REMAP
Ready to enhance your BMW 840i? Contact Onyx Performance to discuss Stage 1 remapping, Stage 2 options, gearbox tuning and supporting performance upgrades. Our team can help you choose a package that suits your vehicle and driving goals.
Contact Onyx Performance
Transform your BMW 840i 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!
