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ENGINEERING THE FUTURE OF PERFORMANCE ™
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BMW B58 ECU Tune
Purchase BMW B58 ECU Tune
  • SKU: 05-458-00106-9

    BMW B58 ECU Tune

  • Advertised gains are estimates of HP and Torque “at the engine” calculated from gains as measured on a Dynojet Dynamometer in ideal conditions and typically show the largest possible change.  Actual gains are dependent on the following: Learn More about Crank HP Vs Wheel HP

    Model – Manufacturers use the same engine in multiple model vehicles and often times they are in a different state of tune, for example: 2008 C63 and a 2008 CLK Black Series.  Both have the same engine, but the C63 has 451hp while the CLK63 has 500hp.  Naturally the C63 will show more gains as it starts at a lower level.

    Model Year – Similar to above, as time progresses, Manufacturers tend to slightly increase power output via software from one year to the next or offer “Performance Packages” with increased power.  The engines remain largely unaltered and as a result, final tuned output remains the same, while the gains are lower as the starting point is now higher.

    Fuel – Fuel quality is HIGHLY important with performance vehicles.  Low quality and/or low octane fuel will greatly impact engine output and potentially even engine health.  Top tier brand premium fuels should always be used to achieve the best results possible.

    Drivetrain – All wheel drive has higher drivetrain losses than rear wheel drive.  This results in lower numbers when testing on a chassis dyno.  Wheel/tire size and weight will also impact chassis dyno results

    Weather/Conditions – Temperature, humidity, altitude, and air density all impact engine performance.  Heat, high humidity, and thin air will all work towards reducing engine output

    Engine Health – Higher miles tends to result in increased build up and lower compression which can and will impact engine output.  Properly maintained engines will have better performance than abused or neglected engines.

    Supporting modifications – The highest power levels require supporting modifications.  Depending on the engine, this could mean forged internals, built transmission, upgraded fuel system, 110+ octane race fuel, etc.

  • Stage:
  • $599.00 $599.00

  • Prop 65 warning
    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 www.P65Warnings.ca.gov.

Weistec Horsepower 423
Weistec Torque 434
Manufacturer Weistec
Street legal in all the US States No
Engine Family B58
Stock Horsepower 322
See more
year make model trim engine
2026 Toyota Supra (A90/J29) 8AT Turbocharged 3.0L I6 (B58)
2025 Toyota Supra (A90/J29) 8AT Turbocharged 3.0L I6 (B58)
2026 BMW Z4 M40i 8AT (G29) Turbocharged 3.0L I6 (B58)
2025 BMW Z4 M40i 8AT (G29) Turbocharged 3.0L I6 (B58)
2025 BMW X4 M40i 8AT (G02) Turbocharged 3.0L I6 (B58)
2026 BMW M440i 8AT (G22/G23/G26) Turbocharged 3.0L I6 (B58)
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Product Description



The B58 might be the best inline-six BMW has ever built, and the industry seems to agree. As the six-cylinder member of BMW's modular engine family, it shares the same 500cc-per-cylinder architecture as the B38 and B48, but moves to a closed-deck design with a forged crankshaft, giving it serious bottom-end strength to absorb real boost. Factory output was already strong and refined, and the engine's tuning headroom and durability built a reputation that reached far beyond BMW's own showrooms: Toyota chose the B58 to power the revived Supra, and Morgan built its Plus Six around it. When other manufacturers pick your engine for their own halo cars, you know you've built something special.

Weistec's calibration takes that widely-respected foundation and pushes it further still. Calibrated with the same validation discipline as BMW's own factory work, it extracts more from the B58's closed-deck architecture and twin-scroll turbo without touching knock protection, thermal management, or OEM diagnostics. On an otherwise stock B58, that's roughly 101 additional horsepower and 102 lb-ft of torque, turning one of the best production sixes in the world into something even more special.

BMW B58 ECU Tune dyno graph

How Do You Get Your BMW B58 ECU Tune Tuned?

Follow these steps — this is what your specific vehicle needs and supports.

1

Unlock Check

This ECU requires an unlock first

Modern ECUs are often locked down, especially after a dealer software update, which can block bench flashing or OBD flashing. Our ECU Unlock Service removes those restrictions, is done per ECU, and stays active through most future dealer updates as long as the bootloader isn't overwritten.

Read the full ECU Unlock breakdown →
2

Choose Your Tune Stage

3

Core Improvements

Standard with this tune
  • Increased Horsepower
  • Increased Torque
  • Improved Throttle Response
  • Optimized Fuel and Spark
  • Increased Boost
  • Top Speed Limiter Removed
4

Free Add Ons

Want it louder?

Read more about Burble & Pops →

This tune can have Burble/Pops added or increased on deceleration, at no additional charge. Select an intensity below and we'll add it to your order, or mention it when requesting your tune — through the Cypher+ app, your calibration request form, or when placing your order.

Want to stop the stopping?

Read more about Auto Start-Stop →

Auto Start-Stop can be turned off as part of your ECU tune alone, at no additional charge. Just mention it when requesting your tune — through the Cypher+ app, your calibration request form, or when placing your order.

5

Pick Your Tuning Method

See the full tuning process →
1Selected

Cypher Plus

Order a Cypher Plus and tune your car yourself from your phone, entirely through the MyFlasher app. Watch how it works.

2Selected — Pick return shipping at checkout

Mail It In

Remove your ECU or TCU and mail it to us for tuning. Required for some applications.

3Selected — Pick Will call at checkout

In Person

Bring your vehicle, or just your ECU/TCU, to our Anaheim, CA headquarters. Call 714-202-0005 or email sales@weistec.com to schedule.

4Selected — Order through your local dealer

Cypher Pro Dealer

Visit a certified Cypher Pro Dealer near you. Find one with our dealer locator.

6

Complete The Upgrade

An ECU tune alone won't remove all factory limits or fix how power reaches the ground. Add these to round out the upgrade with no limitations.
Read the full CPC & TCU breakdown →

What is a CPC module?

The CPC (Central Powertrain Control) is a separate control unit that manages things like the active exhaust valves, radiator fan, intercooler pumps, and speed limiter. On many newer Mercedes-Benz vehicles, it also houses torque limiters that can hold back an ECU tune from reaching its full potential.

What is a TCU tune?

A TCU (transmission control unit) tune delivers faster, firmer shifts with higher line pressure, reducing clutch slip and increasing the transmission's torque capacity. It's a worthwhile upgrade on its own, or paired with an ECU tune for a fully sorted powertrain.

Your Total  

Good to Know

  • This is a reflash of your original module, not a stand-alone unit.
  • Power gains vary by vehicle, modifications, fuel, and operating conditions (ambient temperature, altitude, etc.).
  • New or upgraded spark plugs are always recommended when tuning.
  • Product may not be emissions compliant. Check local laws prior to installation.
  • Always use a battery charger during programming.