Custom BMW JB4 Map 6 Tunes

Euro Tuning History

The Euro tuning scene originally started gaining steam in the 1970’s, which is when legendary Euro tuning companies like Alpina (BMW), ABT (Audi/VW) and Brabus (Mercedes-Benz) first emerged. The 1980’s-1990’s is considered the golden era of Euro tuning, and when more modern engine control units became common, opening the door for aftermarket ECU recalibration. This is also when piggyback units started gaining popularity, especially systems like the Greddy E-Manage and the APEXi AFC, which allowed enthusiasts to control fuel delivery, ignition timing, and even boost levels for turbocharged cars.

Piggyback systems were an alternative to chip tuning, also known as chipping, which required the ECU to be physically removed from the vehicle to access its internal components. Though chipping was considered by some to be superior to piggybacks, chipping was not without risks. There were also warranty concerns and chipping was highly frowned upon for leased cars. In order to chip tune, the ECU was removed from the vehicle, sent to a chip tuner and carefully opened. After evaluating the circuitry, the chip that stored the engine control data, usually an EPROM (Erasable Programmable Read-Only Memory), was carefully de-soldered from the ECU. The chip was either replaced with a newly programmed one or the factory chip was reprogrammed with an EPROM programmer and soldered back in.

In the 2000’s, OBD-II flashing revolutionized tuning, allowing performance shops and eventually the driver to quickly and easily reprogram the ECU without any physical modification. In 2020, BMW started locking the more complex Bosch ECU’s, which required a bench unlock to OBD flash. The next generation BMW G chassis (and some ///M model F chassis) cars that were built in 2021 or later now require a specialized FEMTO ECU unlock to OBD flash tune. Going nearly full circle back to the the 1990’s and early 2000’s, this FEMTO unlock requires removing the ECU from the vehicle and sending it overseas to be unlocked.

Why JB4 ?

NXTGEN Custom Map 6 for S58 M4 Competition

Vehicle modifications: (FBO) Cat-less downpipes, full exhaust, front mount intakes and a custom transmission tune.

A worthy platform in the FEMTO age

At NXTGEN Automotive we’ve been a part of the Euro tuning world for 20+ years. As enthusiasts, we were a part of the debates between chipping and piggybacks. We gladly adopted flash tuning and then eventually had our cars locked. As die-hard enthusiasts over the decades, one thing has always remained constant. The never ending desire to tune our cars and the associated cat and mouse game between the tuning community and automobile manufacturers.

We’ve had numerous versions of chip tunes, piggybacks and flash tunes on our personal and shop vehicles. We fully understand that in a perfect world, the absolute best tuning method is a quality flash tune. In the age of FEMTO, flash tuning is not a viable option for many enthusiasts who wish to add power. In our professional experience, the JB4 is the best piggyback available, and one of the most affordable and accessible power adding modifications for the B58 and S58 platforms that require a FEMTO unlock.

JB4 advantages | the best one yet

  • The smoothest and most consistent power delivery on B58 and S58 motors we’ve ever experienced from a piggyback.

  • One of the most effective and popular tuning systems for BMW on the market, for several generations.

  • Off the shelf and customizable maps, allowing users to switch between different levels of performance and customize numerous parameters for their specific vehicle.

  • Extensive data logging capability, which enables drivers to record engine parameters, including boost pressure, AFR, ignition timing, throttle position, fueling, etc.

  • Allows for on-the-fly adjustments to boost levels, fueling, and other parameters. This real-time tuning flexibility is a major advantage over many piggyback systems that require manual changes or even physical access to the tuning box.

  • Constantly monitors engine parameters, such as AFR (Air-Fuel Ratio), boost pressure, and temperatures, and can revert to stock settings if any issues arise. For example, if the JB4 detects knock (pre-ignition), excessive heat, or any other anomaly, it can automatically reduce boost or even deactivate itself to protect the engine.

  • For vehicles equipped with wideband O2 sensors, the JB4 integrates the sensor’s feedback to further refine the tune. It uses this feedback to adjust fuel trims and ensure optimal performance and engine safety.

  • Can be configured to handle different fuel types, including E85 blends and port injection setups. This allows for even greater power gains, particularly in turbocharged engines. The ability to adjust fuel parameters to account for these fuels is a unique and powerful feature.

The NXTGEN Advantage

Like flash tunes, the JB4 offers both off the shelf (OTS) maps and a customizable map 6. Also similar to flash tunes, maps customized to your specific vehicle are always superior to off the shelf maps. The reason being, every car is different and will operate and perform differently, even if they are the exact same make, model, year, engine and trim. In addition to normal variation in factory tolerances, location, weather, fuel type and modifications will also make a difference in how a car performs. By honing in vehicle specific parameters, we can provide a more powerful and smoother map vs any off the shelf options. There is no doubt that OTS maps and flash tunes make a notable difference over stock, but the real magic happens when a vehicle specific, data driven approach is taken.

JB4 OTS Map 5, 2024 M4 Competition X Drive

E30 fuel, intake and custom transmission tune.

Across the power band, this OTS map 5 (red arrow) creates more useable power, which is especially evident in the mid range. With the pedal 100% depressed throughout the pull (yellow arrow), there are numerous throttle closures (blue arrow). Additionally, there are some timing corrections and the ignition timing could be tighter (green arrow).

OTS vs Our Map 6

(Map 5) E30 fuel, intake and custom transmission tune.

(Map 6) E30 fuel, intake, gapped down spark plugs and custom transmission tune.

When comparing the OTS map 5 vs our customized map 6, you will see:

  • Reduced throttle closures, both in frequency and the amount of closure. While totally eliminating throttle closures during all driving situations is unlikely, a well dialed in tuning solution will reduce them and provide smoother and more efficient power delivery. Most stock cars will have some throttle closures throughout the power band, but these can absolutely be exacerbated by Jb4. During logging, our shop M4 has always had some throttle closures near the top of the power band, both stock and with various maps. We have reduced the amount of closure, kept it closer to the targeted boost and eliminated many others introduced in the OTS maps with our custom map 6.

  • Increased boost resulting in more power and a stronger feeling vehicle.

  • More advanced ignition timing, also increasing power, efficiency and performance.

  • Less lean operating conditions, especially while using ethanol blends.

These differences result in smoother, more powerful and efficient feeling vehicle, which is also operating under better parameters that are based upon your vehicles specific characteristics. While the JB4 does not specifically overwrite or directly control any of the ECUs functions, map 6 does allow for the adjustment of numerous settings that directly impact many of these parameters. When properly dialed in by those who understand the Jb4 and these various parameters, the results are usually very noticeable vs stock or off the shelf maps.

We ran 3 back to back draggy tests on the same stretch of road, in the exact same conditions and with the same tank of fuel. Why 0-60? The majority of our customers are not spending most of their time at the drag strip or the race track. Therefore, 0-60 is a good real-world test to see how our car is progressing and driving in typical conditions. While our shop M4 felt noticeably quicker with the off the shelf map 5, our custom map 6 was an even more significant step up in power and performance.

Enthusiasts and Professionals

When it comes to custom tuning solutions, the landscape is a bit of a mixed bag. Ranging from direct messaging strangers and blindly sending them Zelle or Venmo payments, to larger-scale corporations and everything in between. At NXTGEN Automotive, we are both passionate enthusiasts and skilled, reliable professionals. We are a full-fledged corporation who has been in business for decades, and we’ve designed, developed, manufactured and sold millions of dollars of our own custom automotive solutions, worldwide. Since the founding of NXTGEN, Inc., we have spent nearly a million dollars on our own vehicles to develop and test the products we make. We use our own vehicles to hone in these solutions, and test them extensively in the real world before ever offering them to the public.

Map 6 FAQs

  • No,

    At this time we only offer our custom map 6 tuning services for automatic vehicles.

    Our process always includes us designing and refining our custom products and services on the vehicles we own and have direct access to. The NXTGEN shop does not currently have a manual transmission B58 or S58 vehicle.

  • This is something that we strongly advise against. The entire basis of our customized map 6 tunes is that they are customized to your vehicle.

    When we provide you baseline map 6 numbers, that is not the tune, but the starting point. We will then dial it in based on how your vehicle reacts and the associated logging.

    The important thing to remember is that no two cars will operate exactly the same. Someone else’s map 6 calibration could be far too aggressive for yours, or possibly even less effective than an OTS map.

    No matter what, if you are not very carefully logging and revising the parameters of someone else’s map 6 for your vehicle, it is risky.

  • Yes.

    While a transmission tune is not required to run a JB4, it is needed for our tunes. Most current flash tunes adjust the factory torque limiter, so it is even more important with the Jb4.

    Even with an OTS JB4 map, it is extremely beneficial. The reason being, the stock transmission tune is not calibrated to allow much more power than stock to the powertrain. Flash tunes adjust the limiters and transmission tunes even further refine the power delivery. In order to make notable gains with a piggyback, you really need to adjust the limiter via a transmission tune.

    When you tune the engine to increase power and torque, the transmission needs to handle that extra power efficiently. A transmission tune adjusts shift points, shift firmness, and overall behavior to match the new power profile of the engine. Without a transmission tune, the factory settings might not optimize the way power is delivered to the wheels, leading to inefficient performance or even mechanical stress.

    Raising the torque limits of the transmission will also reduce throttle closures and allow you get the full power potential from your tune. The enhanced shift logic can be very transformative in all driving situations and driving modes.

    The example logs and times we show will always include a transmission tune, and it has transformed our vehicles as much as the JB4 tune.

  • This is a very common question, and it is not a simple yes or no answer.

    For our S58 tunes, we strongly recommend that you gap your plugs down as directed when you purchase our customized tuning solutions. In order to achieve the results we demonstrate for the S58, gapping down spark plugs is required to match our posted results and example logs.

    The NGK 96206 that is OEM in the S58 motor is the same plug that is used in most other current model 4 and 6 cylinder BMW vehicles. The amount of boost a tuned S58 makes is quite a bit more than a stock 330i, yet the factory plugs and gap remain essentially the same.

    The advantages and reasons for gapping down with our S58 tunes are:

    • Preventing spark blowout: if the spark plug gap is too wide, the intense pressure can blow out the spark before it can ignite the air-fuel mixture, causing misfires and a loss of power. Reducing the gap helps ensure the spark remains strong enough to ignite under these higher pressures.

    • Ensures a strong spark with richer or leaner mixtures: gapped down spark plugs ensure the spark can ignite these altered mixtures effectively, especially under higher loads or higher RPMs where the combustion dynamics are different than stock.

    • Combustion efficiency: after a tune, the engine's increased power often requires a stronger or more precise spark to ensure complete combustion. If the gap is not properly adjusted, you may experience incomplete combustion.

    When it comes to the B58 model tunes, the spark plug gap is more dependent upon fuel type, location and modifications.

    Where a 93 tune in a cooler climate may perform well at the stock gap, without blowout. A more aggressive ethanol tune in a warm climate that has lower quality fuel, would likely benefit from gapping down.

  • Yes, it is recommended to change spark plugs more frequently than the factory recommended intervals when running tunes.

    When tuning an engine, spark plug life can be reduced for several reasons, mainly due to the increased demands on the ignition system and the more extreme operating conditions.

    This is especially true when running ethanol blends and when plugs have been gapped down, both of which reduce spark plug life faster.

    Our general rule of thumb is, change your plugs at half the factory recommended interval. Therefore, plugs that are factory recommended to be changed every 60k miles should be done at roughly 30k miles, unless your specific situation requires something different.

    Additionally, if your plugs are at or above half of the factory recommended change interval at the time of tuning, it is best to change them out.