| Weistec Horsepower | 546 |
| Weistec Torque | 675 |
| Manufacturer | Weistec |
| Street legal in all the US States | Yes |
| Engine Family | S55 |
| Stock Horsepower | 425 |
| See more | |
| year | make | model | trim | engine |
|---|---|---|---|---|
| 2020 | BMW | M2 CS | 7AT (F87) | Twin Turbo 3L I6 (S55) |
| 2020 | BMW | M2 CS | 6MT (F87) | Twin Turbo 3L I6 (S55) |
| 2021 | BMW | M2 Competition | 7AT (F87) | Twin Turbo 3L I6 (S55) |
| 2020 | BMW | M2 Competition | 7AT (F87) | Twin Turbo 3L I6 (S55) |
| 2019 | BMW | M2 Competition | 7AT (F87) | Twin Turbo 3L I6 (S55) |
| 2018 | BMW | M2 Competition | 7AT (F87) | Twin Turbo 3L I6 (S55) |
| See more | ||||
Product Description
The S55 was BMW M's boldest reinvention of the M3 platform in a generation. After two full generations of high-revving naturally aspirated V8 power, BMW M threw open a new chapter for the F80 M3 and F82 M4, returning to an inline-six architecture but wrapping it in twin turbochargers for the first time. The engineering underneath is genuinely special: the S55B30 pairs a dedicated mono-scroll turbo with each bank of three cylinders, runs forged pistons and connecting rods built to handle serious cylinder pressure, and uses a closed-deck block that lets it hold far more of that pressure than the single-turbo N55 it's related to. BMW clearly believed in this architecture, later bringing a detuned version of the same engine to the M2 Competition and M2 CS, giving that compact coupe the same core engine as its bigger M3/M4 siblings.
Weistec's S55 calibration takes that already remarkable platform to a genuinely different level, and it does it with a software-only recalibration: every factory protection strategy, from knock control to thermal management to OEM diagnostics, stays fully active exactly as BMW engineered it. Built with the same rigor and validation process as BMW's own calibration engineers use, it refines fueling, ignition, and boost targets to unlock what the factory left on the table, taking the S55 from 425 horsepower and 406 lb-ft to an exhilarating 546 horsepower and 675 lb-ft on the same factory turbos and fuel system. W.1 is CARB EO-certified and 50-state legal, so that jump in output comes with zero compliance compromise.
Related Items
How Do You Get Your BMW S55 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 tune4
Free Add Ons
Want it louder?
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?
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
See the full tuning process →
Pick Your Tuning Method
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.
Fitment not confirmed
This part is not confirmed to fit your selected vehicle.