| Weistec Horsepower | 715 |
| Weistec Torque | 774 |
| Manufacturer | Weistec |
| Street legal in all the US States | No |
| Stock Horsepower | 563 |
| Stock Torque | 605 |
| See more | |
| year | make | model | trim | engine |
|---|---|---|---|---|
| 2020 | Rolls-Royce | Ghost I | Extended Wheelbase | Twin Turbo 6.6L V12 (N74B66) |
| 2019 | Rolls-Royce | Ghost I | Extended Wheelbase | Twin Turbo 6.6L V12 (N74B66) |
| 2018 | Rolls-Royce | Ghost I | Extended Wheelbase | Twin Turbo 6.6L V12 (N74B66) |
| 2017 | Rolls-Royce | Ghost I | Extended Wheelbase | Twin Turbo 6.6L V12 (N74B66) |
| 2016 | Rolls-Royce | Ghost I | Extended Wheelbase | Twin Turbo 6.6L V12 (N74B66) |
| 2015 | Rolls-Royce | Ghost I | Extended Wheelbase | Twin Turbo 6.6L V12 (N74B66) |
| See more | ||||
Product Description
The N74 carries real weight in Rolls-Royce's history: it's BMW's first production turbocharged V12, introduced as the successor to the naturally aspirated N73, and it's an engine BMW builds specifically for Rolls-Royce to reinterpret entirely in its own image. Where BMW's own V12 applications chase a rev-hungry, linear power delivery, Rolls-Royce's engineers calibrate this engine for what the brand calls a magic carpet ride: near-flat torque from just above idle, almost no need to ever approach redline, and a delivery built to feel more like a turbine than a piston engine. The 6.6-liter N74B66 covered here is the version Rolls-Royce entrusted to the Ghost, Wraith, and Dawn, rated from the factory at 563 horsepower and 605 lb-ft.
Weistec calibrates this V12 the same way it approaches every engine in the lineup: entirely in software, built on top of the factory's own engineering. Every factory protection, knock control, thermal limits, OEM diagnostics, stays fully intact, and the tune is developed and validated with the same OEM-level rigor as Rolls-Royce's own calibration work. On this engine that discipline pays off in real numbers: factory output climbs from 563 hp and 605 lb-ft to 715 hp and 774 lb-ft, the same magic carpet ride, now with considerably more magic underneath it.
How Do You Get Your Rolls Royce N74 6.6L V12 ECU Tune Tuned?
Follow these steps — this is what your specific vehicle needs and supports.
Choose Your Tune Stage
Core Improvements
Standard with this tuneFree Add Ons
Pick Your Tuning Method

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

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

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.

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


