For automotive enthusiasts and racers looking to gather crucial performance data, the Racepak Obd2 Interface, particularly the CL1 model, is a popular choice. It promises seamless data acquisition by plugging directly into your vehicle’s OBD2 port. However, users, especially those with pre-2008 vehicles, might encounter compatibility issues. This article delves into these challenges and explores solutions to ensure you get the data you need, regardless of your car’s age.
The initial excitement of plug-and-play data logging can quickly turn into frustration when the Racepak device fails to connect. One user, “jh36,” experienced this firsthand with their ASA Camaro project. Despite expectations of “full data mining ops” using the Racepak CL1 and a seemingly compatible OBD2 port, the unit blinked green, connected to a phone, and then shut down repeatedly. This issue highlights a critical limitation: Racepak OBD2 interfaces, like the CL1, are often designed with 2008 and later OBD2 systems in mind.
Understanding the OBD2 Compatibility Issue: CAN Bus and Older Vehicles
The root of the compatibility problem lies in the evolution of OBD2 protocols. As “Keith Tanner” pointed out in the forum discussion, the Controller Area Network (CAN) bus system became mandatory for OBD2 in vehicles manufactured in 2008 and later in many regions. Before 2008, while OBD2 was standard, manufacturers had the option to use different communication protocols. This difference is crucial because Racepak’s OBD2 interface is often designed to communicate via CAN bus.
This limitation isn’t always clearly stated in product specifications, which can lead to confusion. As “adam525i” noted, the absence of this detail on Holley’s (Racepak’s parent company) site is a significant oversight. Confirmation of this limitation came directly from Racepak support, as reported by “jh36,” and is also subtly indicated in product descriptions stating compatibility with “2008- or later model vehicle.”
Vehicles older than 2008, like the ASA Camaro project car, may use different OBD2 communication protocols, such as J1850, or lack the necessary CAN bus infrastructure on their OBD2 port pins. This is why simply plugging in a Racepak OBD2 interface into an older vehicle might result in connection failures.
Solutions for Connecting Racepak to Pre-2008 Vehicles
Despite the OBD2 compatibility hurdle, there are alternative methods to get your Racepak data logger working with older vehicles. The most commonly suggested and effective solution is to bypass the OBD2 port for certain data and tap into the vehicle’s tachometer signal.
As suggested by both “Pete. (l33t FS)” and “Paul_VR6,” tapping into the tachometer output provides a reliable RPM signal. For older GM ECUs, like the one in “jh36’s” ASA Camaro (GM #12480054), a tach output signal at 4 pulses per crank revolution is typically available. This signal, similar to that from a traditional coil, can be used by the Racepak device to capture engine speed data.
While this method primarily addresses RPM data, Racepak devices often have additional analog input channels. These can be used to connect to other sensors directly, gathering data like temperature, pressure, or even signals from aftermarket ECUs if OBD2 connectivity is not feasible. For comprehensive data logging beyond basic engine parameters when using older vehicles, direct sensor connections may be necessary.
It’s also important to consider the specific ECU in your vehicle. Race ECUs, as “Keith Tanner” mentioned, might not even support standard OBD2 protocols due to regulatory reasons and focus on proprietary CAN streams. In such cases, consulting Racepak directly about interfacing with non-standard ECUs is crucial. Racepak devices can sometimes be configured to read CAN broadcasts from certain aftermarket ECUs, expanding compatibility beyond standard OBD2.
Key Considerations for Racepak OBD2 Interface and Older Vehicles
- Verify OBD2 Port Pins: Ensure pins 6 and 14 (CAN High and CAN Low) are populated in your vehicle’s OBD2 port, especially for pre-2008 models. Lack of these pins indicates a non-CAN based OBD2 system, likely incompatible with Racepak’s OBD2 interface.
OBD2 connector pinout diagram highlighting pins 6 and 14 for CAN bus high and low for Racepak OBD2 interface
- Tach Signal as an Alternative: For RPM data on older vehicles, tapping into the tachometer signal is a reliable workaround when OBD2 CAN communication is not possible.
- Direct Sensor Connections: Utilize Racepak’s analog input channels for capturing data from various sensors directly, expanding data logging capabilities beyond OBD2 limitations.
- Consult Racepak Support: For non-standard or race ECUs, always reach out to Racepak support for guidance on the best connection methods and compatibility options.
- Check ECU Specifications: Identify your ECU type and specifications to understand its OBD2 protocol support and potential compatibility with Racepak interfaces.
Conclusion
While the Racepak OBD2 interface offers a convenient data logging solution for many vehicles, compatibility with pre-2008 models, especially those lacking CAN bus on the OBD2 port, can be a challenge. Understanding the limitations and exploring alternative connection methods like tach signal tapping and direct sensor inputs is key to successfully using Racepak data loggers with a wider range of vehicles. Always verifying your vehicle’s OBD2 system and consulting Racepak support will ensure you choose the right approach for your data acquisition needs.
