Modified M3s have a reprogrammed ECU.
The BMW M3 delivers a lot of performance right from the factory floor. The M3 xDrive produces 510 horsepower (380 kilowatts), and 479 poundfeet (475 Newton-meters), from its twin-turbo 3.0-liter Inline-Six. However, a new Wrench Studios tune takes it to the next level. To test the tune’s efficacy, Carwow YouTube channel will race the stock M3 against its tuned counterpart in drag races.
Wrench Studios was able crack the ECU of the M3 to tune it. This allowed for more power to be extracted from the powertrain. The ECU tune takes the stock output to 600 horsepower (447 kW) or 516 lb-ft (706 Newton-meter) of torque. This is an increase of 90 % and 37 %, respectively. The M3s sound identical to the tune. They share the same eight-speed gearbox as well as the xDrive all wheel-drive system. It weighs in at 1,780 kg (3,924 lbs).
It is immediately obvious what a tune does. The tuned M3 started the race with a slow start. However, it quickly caught up to the stock performance sedan and passed it in the second race. It finished second by 0.5 seconds. The modified M3 completed the quarter-mile in 10.7 seconds. The stock M3 took 11.2 seconds. The stock M3 was unable to keep up with the rolling races.
The last event is the brake test. This is where the BMW sedans differ. The tuned model has steel shoes while the stock model uses carbon-ceramic brakes. The stock model takes nearly the same distance between them to stop completely, while the tuned M3 wins by one nose. Although your mileage may vary, the race shows how software can dramatically improve a car’s performance.