BMW E90 M3 ECU Tune
$899.00
Product Description
The S65B40 that powered the E90/E92/E93 M3 might be the most remarkable engine BMW has ever built. Rather than evolve the outgoing S54 inline-six, BMW gave the fourth-generation M3 a completely different weapon: a 4.0L naturally aspirated V8 with individual throttle bodies and a race-bred pedigree drawn directly from the S85 V10 in the E60 M5. The block was cast at the same foundry that produced BMW-Sauber's Formula 1 engines, and the finished unit somehow weighed less than the six-cylinder it replaced despite gaining two cylinders. Its 8,400 rpm redline still stands as the highest of any cross-plane-crank V8 ever installed in a production car, and the engine was named International Engine of the Year in its class five years running. Few engines in this class have ever earned a reputation this legitimately.
Weistec's calibration for the S65 is a software recalibration built on top of what is already a motorsport-derived factory design. It's engineered to respect the individual-throttle-body induction and the factory's knock protection, thermal management, and OEM diagnostics rather than override them. Developed with the same validation discipline as BMW's own calibration work, the tune wakes up roughly 25 additional horsepower and 25 lb-ft of torque from this engine's factory hardware, and on a unit this special, that gain lands like exactly the next chapter it deserves.