| Weistec Horsepower | 990 |
| Weistec Torque | 730 |
| Manufacturer | Weistec |
| Street legal in all the US States | No |
| Engine Family | M840T |
| Stock Horsepower | 789 |
| See more | |
| year | make | model | trim | engine |
|---|---|---|---|---|
| 2020 | McLaren | Senna | Base | Twin Turbo 4L V8 (M840TR) |
| 2019 | McLaren | Senna | Base | Twin Turbo 4L V8 (M840TR) |
Product Description
The Senna is McLaren with absolutely nothing held back. Named for Ayrton Senna and built with almost no concession to comfort or everyday usability, it's the lightest McLaren road car since the F1 itself at just 1,198 kg. Its version of the M840T V8 was, at launch, the most powerful internal-combustion engine McLaren had ever put in a road car, making 789 hp with a power-to-weight figure that outran everything else in the lineup. Only 500 were ever built, and every panel and surface on the car was shaped almost entirely by aerodynamics and lap time, not styling.
Weistec's ECU calibration for the Senna is a recalibration of that factory M840T's own software. It works within McLaren's own engineering to extract more from hardware that was already built for extreme use. Knock protection, thermal management, and every OEM diagnostic function stay exactly as the factory designed them. Built to OEM-level standards, it takes this Senna from a factory 789 hp and 590 lb-ft to 990 hp and 730 lb-ft, pushing a car McLaren built with no compromises even further past where the factory stopped.
How Do You Get Your Senna 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
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