Photography by the Author
There is an almost limitless list of sensor types out there available for our use, most of which are already being used in applications where necessary. International-level motorsports facilitates bigger-budget race cars, which begets more technology budget, which means more data logging. Technology from Formula One has been trickling down to sportsman level racing for decades, and nothing has changed. So let’s take a look at what those guys have been using, and what’s making its way into our world.
One of the sensors we see being used on many road-racing cars that are just starting to be used in drag racing are tire temperature sensors. Some of these can display the temperature differences across the width of the contact patch of the tire, which helps a tuner set air pressures, and can also help the driver know when his burnout is near a target temperature for launch. After all, we’re looking for consistent performance, right? These same sensors can often be used to measure track temperature as well, which is an excellent data point for a tuner when configuring power management, or potentially as an adjustment to drivetrain power output in real time, just before and during a pass. There are already engine management systems out there ready to handle these duties, and more arriving each year.
Another helpful data point is electrical current and voltage. Not just battery voltage, but the current required to fire an ignition coil. Some power distribution modules can report data for each device drawing electrical power from the battery or charging system; it’s very easy to spot a failing electric fuel pump or clogged fuel filter by monitoring the amperage required to drive the pump. Greater amperage means the pump is working harder, and we’ve seen this method catch a minor issue before it becomes an engine-destroying problem more than once, recently. Check to see if the power distribution module you’re considering supports data logging at this level, as it can really come in handy!
The next sensor we see gaining popularity is the laser ride height sensor. Common in road racing, these have extra value in high-powered, drag-racing cars as something that can spot a wheelie quickly, and with the right powertrain management system, do something about it! Beyond wheel-stand protection, these can be used to monitor and evaluate aerodynamic downforce at high speeds. We’ve seen one car that experienced 600 pounds more down force at 200 mph than expected, which increased front tire weight beyond their rated loads—a potentially dangerous situation averted!
How about a steering angle sensor? We’ve seen these gaining popularity on drag racing cars already, as this data can tell you about driver inputs (whether the car is tracking straight down the course), the effects of crosswind on chassis control, and more.
We talked with Chris Delgado of Prospeed, in Houston Texas, about a new custom drag car management system he’s developing based on a MoTeC M130 series ECU. MoTeC makes it possible for companies like Prospeed to develop their own customized firmware for specific applications to suit their customers. Chris has been working all year on a new system aimed strictly at drag racers looking to maximize data capture and automate as many functions as possible. His package starts with the Motec M150 ECU itself, which has a large number of Analog inputs as well as multiple CAN network interfaces to be able to talk to a large variety of third party systems onboard.
Chris has his system installed on one of his customer cars to test functions from new sensors such as a 6-axis accelerometer, which reports data such as pitch, yaw, roll, and X, Y and Z acceleration forces (like a typical 3-axis sensor commonly used). In addition to the normal fluid temps and pressures, wheel speeds, and GPS speed, Delgado’s system logs and reports data such as “acceleration force at a given position on track” or “speed at any given point during the pass” (imagine having incremental speed and ET data at any point you’d like to compare) and high sample rate engine speeds that actually show crankshaft RPM rising and lowering with each combustion cycle—a handy way to spot a single cylinder misfiring. With accurate crankshaft and camshaft position data, the tuner can go right to the misfiring cylinder as observed in his datalogs.
Chris’ system adds more than just physical sensors to the data; it’s monitoring internal functions within the M150 ECU itself, such as boost control PID values during a pass to help fine tune or diagnose pneumatic boost control systems. Delgado’s top of the line system includes a customized MoTeC PDM30 power distribution module, which reports data via CAN network to the M150 ECU such as device voltage and current. You can use this data to spot a faulty injector, coil, or boost solenoid. Having this level of detail really helps a remote tuner who can connect via Internet and make handle the data analysis without even being at the track, with the car! All told, Chris’ system is logging a staggering 508 channels of data. To help avoid information overload, custom channels can be created to monitor multiple other channels at once; for example, creating a warning whenever fluid temps or pressures exceed preset maximums or minimums that can vary during the course of a run: “Oil pressure of 20 psi may be fine at warm idle, but during the run at 8,500rpm, we need a minimum of 120 psi and have it give me a warning if we exceed those limits.” This system already helped Chris catch a tire rubbing against the chassis on a customer test car, and set an alarm for the driver to see in real time, and as temps rose well past the comfort range.
In closing, it’s clear that data capture for drag racers is only going to provide more and more channels, and savvy racers will need to keep up the pace. The good news is that all this technology will come down in price as time goes on. Integration of engine controls with displays and data loggers will make complicated systems easier to use and present more insightful data to the racer. The future is now!
Scott Clark is an independent tuner who works with a variety of different engine management and data capture systems. He focuses on engine and powertrain electronics, and has tuned engines in a variety of venues including land-speed and drag racing, Engine Masters Challenge and stationary engines in the oil fields. Scott also teaches EFI tuning classes, hosts instructional webinars and the RealTuners Radio podcast – www.realtuners.com.