| Weistec Horsepower | 540 |
| Weistec Torque | 400 |
| Manufacturer | Weistec |
| Street legal in all the US States | No |
| Stock Horsepower | 500 |
| Stock Torque | 384 |
| See more | |
| year | make | model | trim | engine |
|---|---|---|---|---|
| 2010 | BMW | M6 | 6MT (E63/E64) | 5.0L V10 (S85) |
| 2009 | BMW | M6 | 6MT (E63/E64) | 5.0L V10 (S85) |
| 2008 | BMW | M6 | 6MT (E63/E64) | 5.0L V10 (S85) |
| 2007 | BMW | M6 | 6MT (E63/E64) | 5.0L V10 (S85) |
| 2006 | BMW | M6 | 6MT (E63/E64) | 5.0L V10 (S85) |
| 2010 | BMW | M6 | 7AT (E63/E64) | 5.0L V10 (S85) |
| See more | ||||
Product Description
The S85 stands alone in BMW M's history as its only production V10, and it might be the most audacious engine the division has ever built: a 5.0-liter naturally aspirated masterpiece for the E60/E61 M5 and E63/E64 M6, directly shaped by BMW's Formula 1 program of the era. Rather than enlarging an existing production engine, BMW M designed the S85 completely from scratch, carrying the high-revving philosophy and individual throttle-body induction of its V10 F1 engines into a road car for the very first time. The result is a genuine engineering landmark: it revved to a screaming 8,250 rpm and made 500 horsepower with no forced induction at all, and it made the E61 M5 Touring the only V10-powered production wagon ever built.
With no turbo to lean on, Weistec's S85 calibration works entirely within that naturally aspirated, high-revving character, refining fueling, ignition timing, and throttle mapping to unlock what this legendary V10 still had in reserve. It's a full OEM-level software recalibration, built with the same validation rigor as BMW's own factory calibration and leaving every factory safety system untouched, and it wakes up a genuine 40 horsepower and 16 lb-ft from an engine that already redefined what a naturally aspirated road car could be.
How Do You Get Your BMW S85 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.


