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S55 ECU Tune
Purchase S55 ECU Tune
  • SKU: S55-ECU-Tune

    S55 ECU Tune

  • Gains are at the engine or "crank". Actual gains are dependent on the model, model year, fuel octane, engine health, and environmental conditions. Learn More

  • $1,199.99

  • CARB EO: D-691-4
  • Prop 65 warning

    This product can expose you to chemicals including carbon black, silica - crystalline, formaldehyde, and lead which are known to the State of California to cause cancer, and lead, which is known to the State of California to cause birth defects or other reproductive harm. For more information go to

Weistec Horsepower 546
Weistec Torque 675
CARB Exempt ID D-691-4
Manufacturer Weistec
Street legal in all the US States Yes
Engine Family S55
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year make model trim engine
2020 BMW M4 7AT (F83) Twin Turbo 3L I6 (S55)
2019 BMW M4 7AT (F83) Twin Turbo 3L I6 (S55)
2018 BMW M4 7AT (F83) Twin Turbo 3L I6 (S55)
2017 BMW M4 7AT (F83) Twin Turbo 3L I6 (S55)
2017 BMW M4 7AT (F83) Twin Turbo 3L I6 (S55)
2016 BMW M4 7AT (F83) Twin Turbo 3L I6 (S55)
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50 State Legal S55 ECU Calibration per EO # D-691-4.

ECU Tuning Process: How do I get my ECU tuned?


The Weistec S55 tune provides solid gains through out the entire powerband, with signifigant peak to peak gains as well as large mid range gains!  This is on an otherwise 100% stock vehicle, including the air filters!

In addition to the performance gains, there are a couple options available for race vehicles.  First is the "Burble".  The M4 GTS comes from the factory with this in a mild form.  You can choose "Off" "Mild" or "Aggressive" for the "Burble".  Many seem to prefer aggressive, but we gladly will let you choose based on your preference.

The other race vehicle option would be Catalyst Heating.  On race vehicles, many times the catalysts are removed.  In those cases, there is no need for the catalyst heating which would just be making excessive noise on a cold start of the race vehicle.  If you have a race vehicle with the catalysts removed, Catalyst Heating can be disabled.


Cypher | Powered by Weistec

The Cypher is an optional upgrade when purchasing a Weistec tune for your Fxx series BMW. Simply navigate our website to the tune you wish to purchase. On the tune's product page there will be a drop-down menu giving the option to add Cypher to your tune order. From there, the order is processed, and a Cypher tool will be shipped to you

  • No need to send in your ECU / DME computer*
  • Swap tunes file or return the stock within minutes.
*2019 Models manufactured after April 2019 that have recently received a may not work with OBD2 flashing.  All 2020 models require bench flashing at this time

  Weistec S55 ECU Power 

What does all this mean to you?  More power, sharper throttle response, and consistent performance with out sacrificing refinement. 

ECU Tuning Process: How do I get my ECU tuned?

Key Features:

  • Improved Throttle Response

  • Optimized Fuel, Spark, and Boost

  • M4 GTS "Burble" Mild and Aggressive Options (for Race Vehicles only)

  • Disabled Cold Start (for Race Vehicles only)

  • Disabled Speed Limiter