Performance Chip: Tweaking the Mercedes Power Train

German automaker Mercedes-Benz is among the major movers in the car industry. Backed by its campaign in the race circuit, from the Paris to Rouen tour circa 1890 to the Formula One series, Mercedes-Benz is often associated with the vaunted supercars that have since come out of its production shop. Among these are the Mercedes-Benz SLR McLaren, which stands for “super light racing,” and the 1996 Mercedes-Benz model that the company has developed with car modification expert RENNTech, billed as the world’s fastest sedan. But, since Mercedes-Benz has diverse markets, even its marquee models are rolled out of the shop set up for average driver expectations and standard driving conditions.

Since the race specs of the Mercedes-Benz have little use in typical drive applications, the car’s engine is tuned for street use. However, this does not mean that Mercedes-Benz engines are letdowns. In most cases, the engine is simply re-tuned. Engine tuning is the process of streamlining engine operations toward its maximum power output. It generally involves the delivery of air and fuel into the combustion chamber, and the timing of the spark that lights up the burn material. As both of these engine operations are directed by the Mercedes-Benz electronic control unit, tweaking the delivery and spark timing systems simply involves the replacement of the stock fitted ECU chip.

The ECU chip contains the engine’s lookup tables, which keeps the required engine operation input in a given drive application. When you rev up the Mercedes-Benz, the car’s ECU measure the values gathered by a network of car sensors, like the oxygen sensor, air mass meter, etc. The ECU chip then feeds the ECU with information on the appropriate fuel injection rate based on these values. By replacing the ECU chip with a performance chip, the lookup tables can be optimized to extract the maximum amount of horsepower and torque from the Mercedes-Benz.

The performance chip equips the Mercedes-Benz with a streamlined engine operation. During full throttle drives, for example, the performance chip increases fuel injection in response to the rush of air in the cold air intake system. Since an air to fuel mixture follows a set ratio, a rush of air can disarm the power production. More air consequently can accommodate more amount of fuel. The performance chip tunes the lookup tables in the ECU toward increased production output.

In addition, the spark timing may also be altered to harness more horsepower. A spark that is generated during an appropriate time boosts power production and prevents fuel waste. Engine misfire, on the other hand, doesn't just waste fuel: it may also result in engine damage, like busted HT leads, fume buildup in the exhaust system, etc. Unlike car manufacturers, who place emphasis on issues like reliability, mileage and emissions control, most manufacturers of performance chips utilize more aggressive settings in the fuel and spark timing maps of their performance chips to further tweak the engine.

The Mercedes performance chip is a plug-and-operate part of an ECU. It requires no car modifications, which often include the tedious task of changing carburetor jets and distribution curves.