SKU: 42830320392

McLaren JB4 Performance Tuner for M838T Engines - Burger Tuning

Sale price$629.55 Regular price$699.50
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  • CAN

Ships within 48 hours · Estimated delivery Aug 25 - Aug 30

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Description

McLaren JB4 Performance Tuner for M838T Engines - Burger TuningInstant Horsepower and Torque Gains The JB4 is a plug and play McLaren tuner that plugs into easy to access sensors in the engine bay and works with your factory ECU tuning to remap your boost, timing, and fueling for optimal performance and reduced turbo lag. It features a 64mhz processor allowing sensors to be sampled 800 times per second using dedicated 10 bit digital to analog converters, ensuring smooth and powerful performance. No ECU flash

Instant Horsepower and Torque Gains

The JB4 is a plug and play McLaren tuner that plugs into easy to access sensors in the engine bay and works with your factory ECU tuning to remap your boost, timing, and fueling for optimal performance and reduced turbo lag. It features a 64mhz processor allowing sensors to be sampled 800 times per second using dedicated 10-bit digital to analog converters, ensuring smooth and powerful performance. 

No ECU flash needed and compatible with locked 🔒 ECUs

Unlike other tuning systems, the JB4 includes a fully programmable CANbus system, upgradable firmware, and data logging capability. CANbus allows the JB4 to take into account pedal input, throttle position, gear, engine speed, air/fuel ratio, fuel trims, ignition advance, knock, and many other factors and incorporate those into the performance mapping. It can also read/delete fault codes, includes unique safety features such as keeping boost pressure low until oil and water is up to temperature to provide proper engine and turbo lucubration and drop to a low boost map if the engine starts to overheat, run lean, excessively knock, or over boost. 

The JB4 offers a lot more performance, functionality, and safety than your average performance chip.

The default JB4 map1 runs 4psi over stock peak and tuned maps including stock and valet mode can be selected on the fly using a BMS diagnostics cable or JB4 mobile smartphone adapter.

Installation is very discrete, and it quickly removes without a trace when needed. Includes maps for 91 octane, 93 octane, and E85 (ethanol fuel) mixtures. Fuel economy during normal driving is unchanged. Compatible with all driving modes. Made in USA. 5 year warranty.

Wirelessly Connect to your JB4: Our all-new JB4 PRO smartphone connection is included and wirelessly connects the JB4 BMW tuner to your Bluetooth 4.0 compatible iOS or Android device. This option allows you to record and analyze vehicle and tuning data, change JB4 performance maps, and update JB4 firmware as we release free newer versions with updates, more powerful maps, and new features under development. Our new adapter fits fully inside the JB4 enclosure for enhanced weather protection and a more streamlined look. The JB4PRO Free app features an intuitive easy-to-use interface, help buttons, and advanced log analysis tools that can estimate the performance of your car and help identify any tuning concerns. For more info on how to use the JB4PRO free app click here.

McLaren JB4 Features and Benefits

• Improves 0-60 times and 1/4 mile times
• The JB4 offers a lot more performance, functionality, and safety than your average performance chip
• Quick Plug & Play Installation
• Includes the rugged JB4 billet aluminum enclosure for protection
• CANbus OBDII integration offering unrivaled tuning features and performance
• Improved performance over non-integrated chip tunes
• Runs as smoothly as stock, this is how your vehicle should have come from the factory
• Compatible with all driving modes
• Fuel economy unchanged during normal driving
• Compatible with JB4 Mobile for smartphone logging, tuning changes, and adjustment
• 91 octane fuel or better required for performance gains
• Ethanol (E85) compatible tuning maps
• Able to read/delete fault codes
• Not VIN locked and can be removed without a trace and resold down the road
• Made in the USA
• 5 year warranty

Vehicle Fitment

McLaren
•  all M838T engine variants, McLaren MP412C,570s,570GT,600LT,650S, and more.

What is a JB4?
The JB4 is a plug and play tune available for turbocharged vehicles. The JB4 tuner installs between your car's sensors and its DME/ECU (computer) and manipulates vehicle performance through these connections making your vehicle much faster. While it's not the only tuning system that operates this way, the JB4 separates itself from the competition with much more advanced connection points and processing including CANbus, fuel & spark control, Bluetooth to your smartphone, and a variety of innovative and advanced features not possible with any other system. BMS regularly publishes free mapping and firmware updates adding performance and features as ongoing development allows. In addition, the JB4 system is not VIN locked to your vehicle and can quickly removed and swapped between cars or resold at a later time. Often imitated but never duplicated the JB4 has been the gold standard in plug and play turbocharged performance tuning for over a decade.

Is the JB4 a real tune?

Yes the JB4 is a real tune. By tapping into specific sensors and CANbus for real time vehicle data the JB4 is able to alter your boost, timing, AFR, and/or fuel trims, to a similar degree an ECU reflash would, but without the vehicle ever knowing its been tuned. The result is safe, smooth, and significant power and torque gains while retaining your factory safety systems and without having to unlock/flag your ECU. 


Dragy Results


 


Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
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Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 42830320392

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J. Randle
Bozeman, US
★★★★★ 5
Love them
Color: Pink & Beige, Size: Medium/Large(fits size 8 to 11)
I wear a size 11.5 in ladies shoe and these just barely fit. Butttt after I put lotion on my feet and slipped these on and left them on for about 30 mins. It left my feet really soft! They work great as intended. Would buy again
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Reviewed in the United States on January 31, 2026
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Vonda Kioultzopoulos
West Palm Beach, US
★★★★★ 3
Effective but may be uncomfortable
Color: Pink & Beige, Size: Medium/Large(fits size 8 to 11)
I have eczema on my feet and use a prescription cream that I leave on overnight. I often have a problem sleeping in socks but the silicone feels cool on my feet. The only drawback I have is the opening of the socks feel very tight around my ankles making them uncomfortable on me. I wish the opening was a bit more flexible.
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Reviewed in the United States on September 20, 2025
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Tessy
Louisville, US
★★★★★ 1
Burned my already sensitive feet, too big
Color: Pink & Beige, Size: Medium/Large(fits size 8 to 11)
Feels icky, and the heat gets trapped and literally felt like my feet were being burned by these. The bottoms of these feel prickly and they are way too big. You have to sit still and cannot walk in them.
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Reviewed in the United States on April 22, 2026
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Ms. Mac
Grantham, US
★★★★★ 5
Just as good as paraffin wax
Color: Pink & Beige, Size: Medium/Large(fits size 8 to 11)
I might prefer these socks over paraffin wax. They are comfy and very moisturizing. I use these socks once a week to keep the heels and soles of my feet moisturized between pedicures. I rinse with warm, soapy water then hang to dry. They are hard to walk in, but there's a saying printed in the socks that's says something to the effect of "take a break, stay off your feet" lol I love that as a reminder to put my feet up and relax
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Reviewed in the United States on April 9, 2026
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SKI
West Palm Beach, US
★★★★★ 5
Love these!
Color: Pink & Beige, Size: Small(fits up to size 7)
Love these! As I write this review, I’m sitting in my recliner with these on. I have had other silicone socks in the past and would like to share a few of the things that I have learned. These fit great! The others were 2-3 sizes too big because you could not order a size. I wear a size 7 women’s shoe. I got the smaller size. I walked around my apartment in my old ones and they got kinda yucky. Now, I sit in my recliner, put them on and chill for a few hours. I now take them off and put in a ziplock bag so they stay nice and clean (no cat hair!). I use them once a week usually on Saturday or Sunday as I’m a working girl. Also, I use Auqaphor before I put them on and put cotton socks on after I’m finished. Your feet will be SO soft. This is not a one and done…I do this every week especially during sandal season! I know this was lengthy and I hope you got some tips.
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Reviewed in the United States on April 25, 2026

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