By Douglas R. Glad
Early hydroplane boat racing was a violent affair. The basic chassis design consisted of a lawn chair perched in an open cockpit behind a 400hp Liberty 12 aircraft engine designed in WWII. We've laughed at historical photos depicting the leather-helmeted jockey engulfed in the plume of spray off the bow and the blast of exhaust from the zoomies. But we still want to try it. As rude as it sounds, this was the environment where RacePak data acquisition was born.
The system first appeared in the early '80s as a method of making pit adjustments to propeller and chassis trim without relying on what the driver may have seen or heard during the run. At the time there was lab data that extrapolated the engine's potential in relation to the propeller, but nothing more. The secret of the fast teams was primitive forms of data acquisition that recorded engine rpm during the run to ensure that the engine was running in the peak of the power curve. The data was recorded on a microchip to be analyzed by the mechanics on a printout.
Obviously, rpm is only one of many important parameters of performance. Twenty years later, proprietors of data acquisition technology have added a magnitude of channels and transcended the boat to the dragster and eventually ended up producing a relatively affordable way for the street guy to monitor the events that occur at the track. Whether in a boat or in a car, the idea is the same: Make the acceleration curve as steep as possible. And that is what data acquisition can help you do.
How Does It Work?The best analogy we've heard is the way Rodger Conley at Racepak explained it: "It's like pointing a video camera at the gauges during a lap."
The difference is that you can't point a camera at the driveshaft and tell how fast it's moving or any other component that doesn't use a conventional gauge. Data acquisition sensors allow you to do these things.
The very core of the Racepak system is what is called a V-net (vehicle network) module. Each module is hard wired to a sensor that feeds information to the system by converting mechanical energy into an electronic signal. That signal is collected by a small chip in the head of each module that processes the incoming information and labels the signals for output. In actuality, the modules are doing much more than this, but the practical application is a series of modules that pass information along a single cable to a data recorder or output device.
The simplest system requires only three modules: a power module, input device (sensor), and output device (gauge). To expand the system and start to record data, sensors can be added in-line with their own modules including the V50, which is the entry-level data recorder. The V50 is small enough to be mounted anywhere and can be plugged into a PC using a serial cable for downloads and analysis.
Space prevents us from touching on the infinite variations of this system, but let's say that if you are really serious about racing, you can order a sensor for nearly every conceivable dynamic on the vehicle and record its actions.
Why It Is UsefulData acquisition isn't for getting the most power out of your engine; it's for getting the most performance and consistency out of your car as a complete package.
The most basic aspects of data acquisition for the street machiner on the strip should be engine rpm versus driveshaft rpm, battery voltage, and fuel pressure. These are the dynamics that can indicate what is actually happening between the vehicle and the track in terms of tire spin and transmission management, while comparatively evaluating underhood variables that could effect engine performance.