G80, G81, G82 (2021 – Present)

We bring the ultimate performance potential of the BMW M3 and M4 to life. The latest generations, G80, G81, and G82, are engineering marvels that redefine what it means to drive a high-performance vehicle. The M3 and M4 both feature aggressive styling, cutting-edge technology, and an exhilarating driving experience straight from the factory.

Whether you have the classic sedan (G80), the versatile touring (G81), or the sleek coupe (G82), our expert tuning services can elevate your BMW to new heights. From precision engine tuning on our Mustang 4wd dyno to installing aftermarket parts, JF Automotive is dedicated to unlocking the full potential of your M3 or M4.

Experience enhanced power, sharper handling, and a driving experience that truly reflects your passion for performance. 


JFA Stage 1 Tuning – 600BHP

With the latest Bosch ECUs, traditional tuning methods are currently not viable due to enhanced security measures implemented from mid-2020. All G-Series M3 and M4 models from this period onward feature these new, highly secure ECUs. Fortunately, FEMTO in Finland can unlock the ECU, allowing us to perform our expert tuning.The process involves sending the ECU via a secure courier, typically taking 10-14 days to complete.

We provide three convenient options for unlocking your ECU:


You can send us your ECU for unlocking. If you have the means to store your car during this time, we’ll provide you with easy-to-follow instructions for removing the ECU, which takes about 10 minutes. Once you send us the ECU, we’ll manage the unlocking process with FEMTO.


You can bring your G-Series M3 or M4 directly to us. We’ll take care of the entire tuning process while you use one of our courtesy cars.


For added convenience, we offer a paid collection and redelivery service for your vehicle using our transporter. We’ll handle everything, so you don’t have to worry about a thing.

Please note this dyno graph shows raw data measured at the wheels. Our system then calculates drivetrain losses to produce engine power figures.

We meticulously fine-tuned the ECU using our in-house Dyno and extensive daily driving with our development car. The power output can be adjusted through the BMW Drive selection modes, allowing quick adaptation to various driving conditions.

Once unlocked, we apply our latest UK fuel calibration using the Bootmod3 firmware, which includes several custom features.

Switchable Maps

Our default Map Slot settings, which can be instantly changed using the Cruise Control buttons, include:

  • -Map 1: Stock tune – 542bhp / 479lb-ft
  • Map 2: 95 Octane normal unleaded fuel – approximately 590bhp and 530lb-ft (Stage 1)
  • Map 3: 97/99 Octane Super unleaded fuel – approximately 620bhp with over 550lb-ft (Stage 1)
  • Map 4: Valet Mode

Drivers can switch between these maps using the Cruise Control buttons or by selecting a new map slot within the BM3 App.

Recalibrated Driver Display

All our remaps include recalibrating the Driver Display to show the engine’s new power and torque figures.

Vmax Removal

Our remaps remove the top speed limiter, allowing you to exceed 155mph on de-restricted motorways or at track events.

Custom Exhaust Valve Control

Our remaps adjust the exhaust valve to enhance the exhaust note and reduce drone when cruising, especially beneficial for cars with performance exhausts or downpipes.

Optional Cold Start Removal

We offer the option to remove the Cold Start process that causes the engine/exhaust to produce a loud noise while the ECU warms up the CATs for emissions. This is particularly useful for cars without CATs.

Optional Pops & Bangs/Burbles Adjustment

You can tailor the amount of burbles produced on the overrun. Switch between OEM or custom levels using the phone app, or turn them off completely. All our remaps feature a burble setup similar to the CSL/CS models, providing a pleasant sound in Sports mode.

Adjustable Torque Per Gear

Using a Bluetooth Interface and Phone App, drivers can easily adjust the amount of torque delivered to the wheels with a simple slider. We provide a good default setting for the first 3 gears, but drivers can request more or less torque in 1st, 2nd, 3rd, and 4th gears onwards. This is ideal for managing traction on slippery surfaces or optimizing performance with grippier tyres.


JFA Stage 1 Tuning Module - 600BHP

This tuning package for the G80, G81, G82 (2021 – Present) BMW M3 & M4 utilises the Speed Buster Tuning Module, delivering 600BHP and 760Nm.

We achieve this through a fully recalibrated engine management system (Speed-Buster Module) that significantly boosts both power and torque.

Extensive testing on the road and our Mustang 4WD dyno has allowed us to enhance power and torque, not just at peak values but across the entire rev range, improving drivability and expanding the power band.

The tuning process takes about 2-3 hours. We also offer optional before and after power assessments for an additional fee.

Unlock the Full Potential of Your Vehicle with the JFA Speed-Buster Tuning Module

Transform your driving experience with the JFA Speed-Buster Tuning Module, designed to maximise your BMWs performance safely and efficiently. This module guarantees enhanced power, precision, and reliability, raising your M3’s or M4’s output to 600BHP and 760NM of torque.

Custom-Tuned Performance

Each JFA Speed-Buster Tuning Module is precisely tailored to your specific vehicle. Featuring a multi-channel loom, our modules deliver personalised performance improvements that align seamlessly with your car’s capabilities.

Easy Installation

Enjoy the simplicity of our Plug & Play system, designed to fit each type of vehicle. The installation process is quick and straightforward, taking only a few minutes. If you prefer expert installation, our UK-based support team is ready to assist you at our facility.

Trust and Reliability

  • 30-Day Money-Back Guarantee: Feel secure with the option to return the product if you’re not completely satisfied.
  • Made in Germany: Our modules are crafted with German engineering, known for its quality and innovative designs.
  • Over 20 Years of Expertise: Benefit from two decades of specialised experience in vehicle tuning.
  • 2-Year Warranty: Your investment is secure with our comprehensive warranty.

Why JFA Speed-Buster?

Choosing JFA Speed-Buster means you value quality. We maintain our product development and manufacturing in Germany, unlike many competitors who outsource to reduce costs. This commitment ensures high standards of quality and enables us to offer superior products globally.

Our modules do more than just increase power—they also boost your vehicle’s efficiency and torque by up to 30%, while protecting the engine’s integrity. Featuring genuine connectors and specially developed software, our tuning modules integrate effortlessly, resembling factory-installed components.

Please note this dyno graph shows raw data measured at the wheels. Our system then calculates drivetrain losses to produce engine power figures.



Do you offer a 12 month warranty?

Coming soon…

What is motorsport use?

Motorsport-exclusive components are explicitly designed for track use. While they can be installed on any vehicle, it’s important to note that using such parts renders the vehicle unsuitable for road use and may result in MOT failure.

Will the lifespan of my engine be reduced?

No! Our remaps are designed specifically to improve the performance of your vehicle whilst remaining within the tolerances of your vehicles’ components.

Sadly, in attempt to achieve ‘big numbers’ some other companies over tune engines, placing excessive stress on the engine, transmission, cooling systems, etc, leading to reduced life span and reliability of the vehicle. We pride ourselves in producing reliable remaps which do not over stress your vehicle but still produce impressive results.

What is covered with the 30-day money back guarantee?

In any case where a customer is dissatisfied with any ecu remap software supplied, within thirty days of the supply date, the customer can request their money back. In order for any refund to be processed, the customer must present their vehicle to our workshop and allow our technicians to restore the vehicle to its original state. On successful completion JF Automotive will refund the cost of the remap to the customer.

No refund can be granted unless the vehicle is returned to the original state by JF Automotive. The 30-day money back guarantee only applies to stage 1 remaps and does not apply to other services like pops and bangs, parts or dyno sessions.
If another modification is purchased alongside a tuning file, which relies on a remap to operate, only the cost of the file is covered by this guarantee. We reserve the right to withdraw this 30 day money back guarantee.

Read full Terms and Conditions

Can the remap be reversed?

Absolutely. We offer this service free of charge if the vehicle is brought back to us. We’ll be very surprised if that’s what you want after taking one of our remap products, however in the case of lease cars some customers prefer to put the car back to standard before returning the car. You might want it back to standard if you are visiting a dealer for warranty or service work, again we will do this for free. Should you lose your tuning files due to dealer actions or parts failure we will be happy to re-install the map onto your car free of charge where possible.

What if a main dealer wipes the map with a software update?

No problem, simply bring the vehicle back in and we will take a fresh read of your ECU and write you a new map file free of charge. We offer this as part of our lifetime software support.

Do I need to notify my insurance company?

Whilst the remap is undetectable to dealer equipment, you should notify your insurance company of any modification to your vehicle. Many insurance companies do not penalise you for upgrades of this nature, particularly if you’re tuning for increased economy however a failure to disclose modifications may invalidate your policy. You may wish to enquire with your insurer if the modification will affect your policy prior to choosing one of our services.

Why we don't you offer ECU remapping for £200?!

We get asked, “Why do some tuners charge as little as £150?” There are a few factors as to why we do not offer remapping for £100-£200!

We supply custom written files for each vehicle that we remap that take in to account condition, milage and customer request of each vehicle. Our services are fully insured with a 30-day money back guarantee and lifetime support for the tuning software supplied. We constantly invest in the most up to date tuning and diagnostic equipment and software and we offer a quality service to all our customers.

Overall our custom supplied tuning software is of the highest standard that we know of, so if you want the best of the best, choose JF Automotive.

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