In this technology-driven hobby that we all partake in, data, as they say, truly is king. The team at Racepak has been providing the ability for advanced data acquisition to professional motor racing since the mid-1980’s. Since that time, not only has their technology grown by leaps and bounds, but it has trickled down to the automotive enthusiasts and grass roots-level drag racers that form the very core of our industry.
Our upgraded UDX Replay Dash, now with data logging capability, mounted up in our ’65 Mustang. In the meter you can see the sweeping RPM tachometer readout, along with a digital readout of the engine RPM. At top left is our air/fuel ratio, while water temperature, oil pressure, and air temperature are displayed in order along the bottom. Multiple pages can be programmed if you have additional sensors, allowing you to see every channel in real-time or Min-Max Recall Mode right no the dash.
Racepak’s UDX line of programmable, plug-n-play digital dashes are part of this entry-level approach to delivering data into the hands of racers, providing them with invaluable information about their vehicles in an affordable and relatively easy-to-learn package.
“The LDX Logger Dash is an entry-level data logger and dash combined, that’s intended for hobby racers, weekend warriors, and bracket racers,” explains Racepak’s Roger Conley. “It’s a unit that’s set up for cars that don’t require or have a G-meter, so it’s a perfect fit for grassroots bracket and index racers.”
The Logger Dash At A Glance
With four screens, 20 programmable displays, warning lights and function buttons, shift light and shift point programming, and best of all, stand-alone functionality, the UDX line offers a great way for racers and street-strip enthusiasts to monitor a wide array of functions in their vehicles. What’s meant by standalone is that, unlike higher-end dashes used by professional race teams that require Racepak’s advanced data recorders to gain the information shown on the dash, the UDX dashes can be used without a separate recorder.
It’s a unit that’s set up for cars that don’t require or have a G-meter, so it’s a perfect fit for grass roots bracket and index racers. - Roger Conley
Racepak has three distinct versions of UDX dashes, beginning with a Street (display only with street car options, like turn signals), Replay (display and replay), and Display Only (which is designed for use in conjunction with V-series recorders). A fourth dash, with data logging capability, is offered as an upgrade to the Replay model, which plays back the data gathered on the most recent pass on the dash. We’ve been utilizing this very model in our Project Biting The Bullitt street/strip ’65 Mustang.
The Logger dash takes this functionality a step further, with the ability to download the recorded data from the dash to a computer for analysis using Racepak software. In essence, you can have much of the same data at your fingertips that more fully-featured data recorders offer the racer.
Logger Dash features:
• Engine RPM • Drive shaft RPM • Oil pressure • Water temperature • External warning indicator output • Internal warning indicator light • Six gear shift light output • V-Net port for expansion of up to 32 additional channels • Minimum and Maximum recall • Electro luminescent(EL) back light
Racepak's V-Net Technology
The Racepak UDX dashes are compatible with the company’s revolutionary V-Net technology that allows one to transmit up to 12 sensors through a single cable in what Racepak compares in simple terms to a power strip. Each V-Net cable features a V-Net module that contains scaling and calibration values, the name of the channel, and other sensor-specific information that creates a “smart sensor.” The LDX dash includes a specific port on the rear of the unit for V-Net sensors, of which 32 can be connected simulateneously.
“The Logger dash is a relatively simple approach to data acquisition, because it’s an all-in-one unit that doesn’t require the hassle of mounting a data logger in the car and then buying a dash,” says Conley. “Of course in being an all-in-one, it also brings a much more attractive price point to the racers that it appeals to most. But the key to this dash, like all of our V-Net products, is that it’s expandable to include a range of sensors, either at the time of purchase or later down the road. It’s fully compatible with the plug-n-play V-Net system.
“We see a lot of people buying the Replay dash initially for instrumentation and to replace a replay tachometer,” Conley continued, “but as they get more familiar with the unit, they upgrade to the LDX so they can download the information and view the data in more detail. Regardless of the type of car you have, there’s just no good reason not to have data acquisition available to you because, especially in drag racing, there’s no such thing as the perfect run — you can always use data to make improvements, whether it’s performance, consistency, or both.”
When you flip the dash over, you’ll find four ports that provide the connectivity needed for a range of setup options. The first of these, Port A, is used to connect the power source for the dash. Port B connects the shift light and warning light outputs, while the Serial Port is used to program the dash and download the recorded data to a computer.
Here you can see a glimpse of our wiring schematic on the back side of the dash. The large plug at left is our V-Net cable, which is transferring channel data from our air/fuel wideband (Racepak AF1), and our intake pressure and intake air temperature sensors, which are wired into the USM. The AF1 and our USM box are “daisy-chained” and plugged directly into the back of the dash. The built-in channels (oil pressure, engine RPM, driveshaft RPM, and water temperature) all use a single wire connection that’s part of a bundle plugged straight into a port on the back of the dash.
The last port is intended for connecting as many as 32 additional analog or digital input sensors into the dash. This is done utilizing Racepak’s V-Net modules, which can be daisy-chained in any order (as many as 32 of them) using a V-Net extension cable connected to the V-Net port on the dash. This allows you to measure something like exhaust gas temperature, and can be configured into the dash using the DataLink II PC software programming kit or the ‘Scroll Mode” function within the dash.
To accomplish this, we’re using a USM (Universal Sensor Module), which can handle up to four sensors, of which the channels can be configured for a 0-5V sensor output, Racepak coolant temp, GM air/coolant temp, square/non-square wave RPM, a voltage event, or a ground event. With the USM, we can use our own 0-5V sensors to connect four additional inputs to the dash, including intake air temperature. In our setup, we have our USM box connected via V-Net, with our Racepak AF1 wide-band connected via the same V-Net chain, with everything then going into the dash directly.
The cable shown at left, which looks similar to a headphone cord, is used to convert the outgoing connection from the dash to a serial cable to connect to our laptop computer to transfer the recorded data and to setup the dash's display. At right is the driveshaft speed sensor and collar, mounted just forward of the pinion yoke.
We’ve also installed a driveshaft collar and sensor just forward of the pinion yoke, which provides us with valuable wheel speed data, which we can then use to determine wheel spin. When plotted on the computer, this channel should, on a good pass, show a smooth, linear increase. Large, quick spikes naturally indicate the presence of wheel spin.
Display Modes At A Glance
Among the useful on-dash features is the Min-Max Recall, which provides you with a quick snapshot of the maximum values for reach sensor recorded during a pass down the track.
The LDX dash has six display modes: Setup, Real-time Mode, Scroll, Min – Max Recall, Recording, and Playback.
Like the Replay dash, and of particular usefulness for racers wanting a quick snapshot of their run, the Min-Max Recall allows for a quick look at the minimum and maximum values of each connected channels. From RPM to oil and water temperature, to intake manifold temperature (if you so choose to connect such a sensor/channel) can all be viewed quickly right on the dash display.
In Record Mode, the dash will record all channels except warning indicators, and with one megabyte of internal memory, can store a maximum of 200 seconds of continuous recording. Once recorded, the data be played back on the dash or, as the logging feature provides, through Racepak’s DataLink PC software on your laptop or desktop computer.
As mentioned above, the LDX dash uses Racepak’s DataLink II PC software to download data from the dash itself, and it does so using a supplied serial communications cable that connects to the serial port on the rear of the dash. Before you can begin logging any data, you must first set the dash up through its configuration file. This file, accessed through DataLink, modifies the setup and allows one to edit the parameters for each of the devices/channels that you have connected and plan to record.
This configuration includes the basics, such as the name, the serial number, input number, V_Net ID, and sensor type for each channel, along with more detailed setup parameters including channel scaling (the calibration factors for the sensor), defining how DataLink will graph the data, and modification of the user-settable options for each device. Racepak’s documentation walks through this process in greater, step-by-step detail than we can go into in the confines of this story, but these are the main ingredients of the configuration process.
Once you have all of your information and parameters set, you’ll need to send the configuration file for the channel to the dash itself, which as you guessed, is done by connecting the serial cable between your computer and dash and transferring the new information. This process must be repeated each time you wish to make any changes to a specific channel.
Dash Display Properties
Within the DataLink software you can customize the layout of the on-screen display of the dash, in terms of which sensors appears on which pages, where they’re located on the display, and their displayed value ranges.
Along with the parameters for each channel, you can also modify the layout of the dash display through DataLink. The LDX dash has four screens that can be cycled through using the “Display” button on the dash, and these pages and the variables for each channel can be modified to your preferences. Each of the screens are displayed graphically on your computer screen as they are seen on the dash, and by simply selecting the channel, you can alter these values. So if you want to display driveshaft RPM in increments of 250 RPM’s, 500, or some other value, you can do so.
In addition to the many configurable options, you can also configure the trigger values for the warning lights on the dash. You can see that we’ve set -100 (a temperature the sensor will never see as the minimum value and 200 degrees as the warning light trip.
Configuring Record Parameters
Lastly, we come to the record parameters of the LDX dash and the DataLink software. Within the System Options section, you can establish your record length, configure the Record Enable channel (the alternative record triggering method, which we’ll discuss in a minute, and its threshold parameters). You can also configure the Record Start Threshold for this alternative trigger, as well, so if you want it to begin when engine RPM reaches beyond 3,000, you can select the channel and enter the desired RPM value.
Once you have all of your information and parameters set, you’ll need to send the configuration file for the channel to the dash itself, which is done by connecting the serial cable between your computer and dash and transferring the new information. This process must be repeated each time you wish to make any changes to a specific channel.
Logging The Data
Any time the remote record or “REC” button on the dash is pressed, the dash will begin to record. Along with manual triggering, you can also configure the dash with an alternate recording trigger, such as an RPM threshold or value in one of the other monitored data channels. In doing so, you can have the system automatically begin recording as you pull into the water box or at the starting line.
Once the recording begins, it will continue until the maximum record time is reached. This record time, which is factory defaulted at 600 seconds or 10 minutes, can vary based on the number of channels being recorded and their sample rates, all of which is configurable with DataLink. Like the Replay dash, once you begin a new recording, all previous recorded data is erased. For this reason, you will want to download any run data you wish to keep onto your computer after each run.
Here you can see an example data log from a run inside DataLink. You can see our connected sensors (engine RPM, air/fuel ratio, manifold air temperature, and manifold pressure) graphed out.
Like we did in the configuration process, the recorded data is offloaded from the dash in the very same — albeit opposite — manner that we transferred the configuration data, with the use of the serial communications cable. Once uploaded, you can enter the year and track information, as well as race type and race sequence. The system automatically enters the date and time.
Along with real-time replay and Min-Max Recall of the recorded data on the dash display, you can also establish a real-time telemetry session between the dash and DataLink that show real-time information on your computer screen, which is perfect for tuners working on an a chassis dyno, or for those wishing for a more detailed look at their information in much greater detail.
If you already own a Replay dash and opt to send it in to upgrade to an LDX Logger, Racepak will update the internal firmware for the dash, and provides the DataLink II software and required software license key on a flash drive to get you up and running with your data acquisition.
As Conley expressed and racers and tuner the world over will agree, data acquisition is a truly invaluable asset to anyone looking to gain the utmost in performance. Gaining access to the intricate details of a vehicle provides unlimited potential to gain knowledge and better understand what’s going on during a given run, allowing tuners to make exacting adjustments based not on assumption, but real, sound data plotted out in a way that’s catered to their exact needs. And for the grass roots crowd, the LDX Logger dash provides just that.