Many customers ask for ways we can upgrade engine power output. We have many tricks in our bag, but one of the most effective methods is software. Since about 1990, we've enjoyed the early Bosch Motronic fuel injection system. It was the first time we had the luxury of having programmable chip tuning in the VW/Audi line. Since then, technology has come a very long way.

Before I discuss the current level of software tuning, I'd like to take a moment to familiarize you with what exactly a "chip" is. A chip is a term used to describe a small integrated circuit containing software. It's usually mounted in some fashion (plugged into a socket or surface mounted) to the printed circuit board of an engine Electronic Control Unit (ECU). The ECU is the "brain" that controls the fuel injection system of the engine, and a host of other critical systems not related to fuel injection. Newer vehicles have an ECU for every sub-system (ABS, Steering, climate control, etc.). When we talk about a chip in the performance context, we're talking about an actual chip that is modified with new software. This new software is programmed into the chip on the engine ECU, and the result is more engine power than the original factory software provided.

To make more power, the software upgrade does a few things of note. In naturally aspirated engines, the key to making more power is advancing the ignition timing. In turbocharged engines, the key to making more power is usually raising the level of boost (compressed air) and retarding the ignition timing below stock values. When doing this, the fuel quality must be improved to at least 91 octane (avg. RON+MON). Timing isn't the only value that changes. Air/Fuel ratios are also taken into consideration. Fine tuning the fuel being injected has a very dramatic affect on power output. Too much fuel causes fouled spark plugs, poor fuel economy, numb throttle response, and loss of torque. Too little fuel causes high exhaust gas temperatures (EGT), which can lead to exhaust valve failure or piston damage. If the engine is run too lean on fuel, catastrophic failure can occur. In the end, more fuel is safer than less fuel. It's a careful balancing act of ignition timing, Air/Fuel ratio, EGT, and boost pressure (if applicable). When all these values are set to ideal conditions, the engine makes more power than stock. When you purchase a chip, that's the idea. A good performance chip offers more power, better fuel economy, and improved drive-ability in everyday situations.

As vehicles become more dependent on computer controls, it's easier to rely on software to make changes in performance. The beauty of software is in its precision and ability to use an array of sensors to manage systems. Adaptation is constantly occurring as the ECU's processors receive inputs from sensors (coolant temperature, engine speed, mass-air flow, etc.) and react. Fuel injection has evolved to the point where we have an electronic On Board Diagnostic system designed to alert humans to potential areas of concern. An alert is known as a Diagnostic Trouble Codes (DTC). The DTC is stored in the software coding of the ECU and can easily be retrieved by a service technician when using a scan tool. You can also think of the OBD system as a method for communicating with the engine ECU via a scan tool or hand held computer.

The method of reprogramming the engine ECU with new software has evolved. I think this is simply a reflection of the emerging technologies offered by automakers. It's also a testament to some very intelligent aftermarket engineers who are truly dedicated to developing new technologies themselves. I'd love to explore this further, but discussing OBD communication protocols, BUS systems, binaries, and ECU addresses is not within the scope of this article. In the past, we would physically change the main chip located on the ECU and replace it with one programmed with performance software coding. To do this, we had to remove the ECU from the vehicle and open it up. These days, things have changed. The current method of reprogramming ECU engine software involves a more advanced process. This new process is less intrusive. It's called serial programming, and we use the existing OBD diagnostic port in the vehicle to do it. Using a special cable and computer, we write new performance software into the ECU with it remaining in place. This is a software only approach, so no hardware is changed at all. We don't have to remove the ECU using the serial programming method. This means that none of the factory hardware has been physically altered. We're simply overwriting some areas of the ECU and writing new software to other areas.

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