When the sport of organized drag racing first came to be, data acquisition consisted of what the driver could remember, and what his crew thought they saw as a car made laps on the track. Then came the advent of video recording equipment that was affordable and a whole new world opened up. A team was able to take a recording of a car making a run down the track, rewind it, watch what the suspension was doing, hear the engine note on the hit and downtrack, replayed over and over until the team was able to plot a course of action based on the perceived performance of the car.
And then datalogging equipment showed up on the market, and all of a sudden, instead of guessing at what was thought to be happening, actual data could be recorded, then dissected and dissected again. Dataloggers took the perceived data acquired through the use of video and turned it into real, measurable data produced by the car, rather than what was interpreted by the crew members sight.
Spencer Eisenbarth and Ron Armstrong formed Competition Systems Incorporated, the parent company of Racepak, to build data acquisition systems that could survive in the harsh environment of a race vehicle. In fact, their first partnership came about when Armstrong was trying to develop a system for the Unlimited Hydroplane he was piloting at the time back in the mid-’80’s. The development of that initial system has turned into a complete lineup of data acquisition parts and pieces that are capable of recording every single operating parameter on your car, and subsequently turning it into data for your interpretation.
It’s been said that a data acquisition system is a necessity in a drag car, and we’re here to tell you exactly why. We enlisted the help of Racepak’s Roger Conley in dissecting the Racepak lineup, where you’d want to start, and what parts and pieces are necessary to begin a new era of tuning your machine.
The company offers four different dataloggers that can be used for drag racing that offer varying levels of ability depending upon what the end-user requires for their particular combination. Three of the units – the Sportsman, V300SD, and V500SD – are standalone logger systems, while the fourth, the LDX, is a dash display and logger system, that we recently profiled in this article.
As the LDX is not Racepak’s traditional logger, but an all-in-one unit that combines the display capabilities with a built-in logger, it doesn’t offer the same types of features that the standalone units supply.
“The LDX Logger Dash is an entry-level data logger and dash display that’s 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 LDX is expandable to allow the user to add some of Racepak’s V-Net sensors to measure other parameters and serves as an excellent replacement for a traditional playback-style tachometer. For a racer that’s looking to monitor more than the basic-level sensors included with the LDX, stepping up to one of the company’s standalone loggers is the next step to learning how to tune a car based on data interpretation.
If you make a change, you can see the change in the data, and then see how the car responded to the change at any point on the track. – Roger Conley, Racepak
The Sportsman Series datalogger is designed to meet every requirement a typical sportsman racer might have, including a dual-axis G-meter to record both acceleration and lateral G’s.
It’s built in a lightweight composite housing and will measure up to 21 channels of data, six of which are user-programmable through Racepak’s V-Net CANbus system. It’s also upgradable using Racepak’s 2 or 4-channel upgrade packages to cover a maximum of 18 V-Net channels.
The Sportsman Series does have limitations, namely in the number of channels that are available for recording, and that it’s unshielded and cannot be used in a magneto application. “All of the dataloggers monitor engine RPM, driveshaft RPM, and battery voltage right out of the box. They have a driveshaft collar to monitor driveshaft RPM, with the sensor and wiring in the box,” says Conley.
“The way these systems are designed, you should be able to take them right out of the box, hook them up and use them. We include a USB-to-serial adapter and an SD card reader for the dataloggers that use those cards, so you shouldn’t have to go out and buy anything at that point.”
The Sportsman system also has an internal 12-volt event logger that can monitor a smaller nitrous system or other input such as a transbrake’s application.
It also has the ability to access eight EGT sensors without maxing out the logger’s channels. This system is targeted toward the weekend bracket racer who’s looking for consistency and performance, but may not be searching for every last bit of elapsed time from their car.
“The Sportsman series logger was designed for a first-time user. The Sportsman logger is something that’s best used in naturally-aspirated cars, and power-adder cars running high 8’s or slower – that’s the target market,” says Conley.
The company’s flagship product, the V300SD, is the most popular unit by far, and offers the majority of the features offered by the company. Like the Sportsman Series, it logs engine and driveshaft RPM, lateral and acceleration G’s, along with battery voltage. In addition, it adds the capability with a dedicated high-speed port to monitor shock velocity and travel sensors. The V-Net connection in the V300SD will monitor up to 56 channels of data, and when combined with the four digital, four analog, and three internal channels, gives the V300SD a total capacity of 67 channels of data.
The V-Net channels in the V300SD will sample up to 100 times per second, while the four analog hard-wired channels are capable of up to 1000 cycles per second. The digital inputs will handle RPM, switch contacts, and timing intervals at 1000 Hz, allowing a massive amount of data to be run through the system and recorded for dissection after each run.
One item Conley stressed during our conversation is that Racepak offers interface units that can be implemented with all of the popular engine management and ignition systems on the market.
“In today’s world, what’s happening is that we make these interface units, and most guys if they’ve never had a datalogger, will migrate to the Sportsman Series because it’s under $1,000, thinking it will be fine. They don’t realize that they can connect with an MSD Power Grid and log up to 12 channels right out of the box. Or the popular EFI systems, which will add up to 13 to 20 channels of data that they’ll stream to our loggers. These events all interface through the V-Net, which take up the corresponding number of channels – in many of these cases a V300SD will be much more appropriate,” he explains.
Where this comes in handy is when a user is building an EFI system for use with the car — they only have to buy one water temperature sensor with the EFI system, and can forgo the purchase of a separate Racepak water temperature module – the information can be transported right through the V-Net to the Racepak logger.
“For expansion, we use our V-Net system, and all of the V-Net sensors are interchangeable no matter which logging system you own. For example, if a customer purchases a Sportsman system and outgrows it, all of the V-Net stuff stays on the car and can plug right in to the next step, so you’d only be changing the box and harness to grow your system. All of the pressures, temperatures, EGT sensors, those can all stay in the car,” says Conley.
The V500SD logger is targeted more at a professional-level racer, and in conjunction with that market, offers all of the same features of the V300SD but has the capability to monitor 56 V-Net channels, 8 digital channels, 4 analog channels, and 3 internal channels. And, believe it or not, there are racers who actually monitor that many channels of data.
“Take for example a racer running a SmartWire, an MSD Power Grid, and a BigStuff3 – you’ll max a V300SD out instantly. You have to remember, with a turbocharged car, you have all of the EFI channels to look at. They’re all running a Power Grid, so you have four or five channels there, guys are looking at boost pressure before and after the intercooler, inlet temperatures, eight EGT’s, O2 sensors, transmission pressures and temperatures – sometimes in multiple places in the transmission,” says Conley.
In addition to all of the channels the V500SD can monitor, it brings with it the ability to interface directly with Racepak’s SmartWire System, which we recently detailed for even more total datalogging capability. The SmartWire interface adds another 64 channels of datalogging to the V500SD for an absolute total of 135 total channels – or more channels than the average user can comprehend. The V500SD also has USB direct communication that plugs into the USB port on your laptop, meaning that there is no need for a USB-to-Serial adapter.
Another neat feature on this top-shelf unit is the optional Bluetooth upgrade that includes a matched Bluetooth dongle for seamless integration that allows the user to monitor the recorded functions in either graph format or on eight virtual gauges while the vehicle is running. It can also be equipped to monitor overall timing or individual cylinder timing on those vehicles using the proper programmable ignition system, like the MSD Power Grid.
The G-Meter And Driveshaft Speed
“People need to understand how important the G-meter is, even on an entry-level combination. A drag race, by definition, is an acceleration contest between two vehicles. It’s one of the most important sensors you can have. If you told Austin Coil [John Force’s former crew chief] he’d have two sensors to monitor on a car, he’d choose driveshaft RPM and the G-meter. Your goal as a heads-up racer is to get the driveshaft to increase speed as fast as it possible can without losing traction. That’s how you get maximum acceleration throughout the entire run,” says Conley.
Measurement of driveshaft speed is just as important – it will tell you whether you’re losing traction and whether the driveshaft speed is increasing throughout the run properly.
Racepak offers two different display dashes that are designed for drag racing, and interface directly with any of the three datalogging systems – the UDX and the IQ3. “For drag racing, we offer these two dashes. The IQ3 is a display-only dash, and the UDX is offered as a display dash, as a replay dash where a guy can just buy one and use it like a playback tachometer, and the logger dash, which is the LDX.
The UDX display dash utilizes a larger form-factor and gives the user four different screens with 20 programmable displays to monitor the most critical of engine functions. Each page is displayed at the push of a button, and the engine RPM sweep bar is always in place. A shift-light output is standard and the light can be programmed right on the screen. There are also warning lights on either side of the green-backlit LCD that are programmable for either low- or high-threshold warnings for the function of your choice. The UDX has pre-populated screen definitions that can’t be customized – you just check boxes in the software to set each item on the screen using Racepak’s definition.
The IQ3 is the top-line display dash product. It offers the same four screen options as the UDX, but with a total of 28 programmable displays. The smaller form-factor has a corresponding smaller RPM bar, allowing more room on the screen’s real-estate for sensor-monitoring. It offers the same features as the UDX but adds user-defined progressive shift light capability built right into the dash, a gear indicator, and can even be configured between metric and Imperial measurements for those of you across the pond. The IQ3 uses a bright blue backlight for comfortable viewing in all situations. The IQ3 differs from the UDX in that you can tag each display channel yourself and type in your own definition for each value.
Both the IQ3 and the UDX offer plug-and-play installation with the Racepak V-Net and the dataloggers detailed here, and we can attest to their simplicity of operation as we’ve used both units on more than one occasion.
What Sensors Do I Need?
As there are four different combinations a drag car can have – naturally-aspirated, nitrous-injected, turbocharged, and supercharged – each combination will typically monitor different sensors to achieve the maximum tuning advantage and performance.
A naturally-aspirated car will use a group of basic sensors in operation. Driveshaft RPM and acceleration are a given, and if there’s a vacuum pump, the racer will want to monitor pan vacuum, fuel pressure, and air/fuel ratio.
In comparison, a nitrous car will use the same group of sensors, but add bottle pressure into the group. “Measurement of exhaust gas temperatures is also very important for a nitrous racer, because the racer really needs to be able to see what’s going on in each cylinder. The EGT is more of a diagnostic tool than a tuning tool in those applications,” says Conley.
Turbocharged or Supercharged
Turbocharged and supercharged racers use a similar group of sensors to one another. Measurement of boost is critical, as is an interface with the engine management system, along with EGT’s – those are the main things to monitor for racers with those combinations.
Chassis Tuning Through Sensors
Another area where a racer can gain great insight into the performance of their car is by setting the datalogging system up with some or all of the various chassis monitoring sensors that Racepak offers.
“Shock travel gives information about how the shock or strut is responding as the car is moving down the track. If you’re making shock adjustments, you’ll be either slowing down or speeding up the shock in either compression or extension – you’re changing the rate of those items. So if you make a change, you can see the change in the data, and then see how the car responded to the change at any point on the track,” says Conley.
Another item Racepak offers is a ride height sensor, which measures exactly that – the distance between the sensor and the ground, from 0-15 inches. This comes in handy in a situation where the front wheels are picked up off the ground – in those instances, a shock travel sensor becomes maxed out and therefore unable to display any further data until the wheels come back to earth.
“Ride height sensors can even be mounted on the rearend housing, so that when the car launches, you can see exactly how much the suspension is compressing the tire. When you start making adjustments, you can see how the chassis responds to changes and plants the tire,” he explains.
As you can see, there are a multitude of options to set up your first datalogging system. From the LDX logger dash to the full-on V500SD, Racepak offers an absolute ton of options to monitor every single function of each system within the car. Don’t be overwhelmed – knowledge is power, and with the inclusion of a Racepak system in your car, you’ll be well on your way to being a more informed racer that can make tuning decisions based on actual operating conditions observed on the racetrack instead of taking a stab in the dark at what you think is happening.