Frequently asked questions
A baseline tune is the first tune you’ll get after sending in your car’s stock file (also called a “read file”). It makes only small changes from the original settings, and most features won’t be turned on yet—like DMS, launch control, or auto start-stop preferences.
This tune is mainly used to:
Act as a starting point for future tuning.
Make sure everything works after installing new parts (like upgraded turbos or injectors).
Think of it like a safety check. It doesn’t add power—it just makes sure your car is running smoothly and safely before making more significant changes.
Aftermarket parts that can be attached to the vehicle without opening the engine or requiring major modifications.
Typically, these parts are "upgrades" for same-type OEM components that provide greater benefits than the original part (example: Intercooler).
Ultimately, these upgrades contribute to a more efficient combustion process that results in greater power production from the original, unmodified engine.
A "full bolt-on" car is one that has most or all of the available bolt-ons installed.
To find out which bolt-ons we recommend, please see our FAQ: Are there any recommended modifications?
A file that tells VCM Scanner or the TDN App which data points to monitor and record during a data log.
If using the TDN App, these will be configured for you when your baseline tune is sent.
If using VCM Scanner, the channels file will be sent via email with your baseline tune. You must load this file before logging.
This is a tune that has gone through the initial Data Logging and Tune revision process.
When complete, you'll receive an email stating: "Your tune is now complete."
What this means: Our tuner has determined there are no opportunities for further improvements based on your data logs, tuning goal, fuel type, modifications, etc.
What this does not mean: No further changes can be made. You can request refinements anytime, including adjustments based on your experience over time.
Digital tokens used to license your vehicle’s ECU/TCU for tuning. You need a certain number of credits to unlock your vehicle for flashing custom tunes.
Once unlocked, you can flash the ECU an unlimited amount of times with the same device.
See Credits 101 from HP Tuners for more information.
A custom tune is built using your vehicle’s stock calibration and the information you provide during checkout or in your tune request (such as fuel type and performance goals). It is tailored specifically to your setup and driving needs.
See: What's the difference between a custom tune and off the shelf (OTS) tune?
A data log is a recording of your vehicle’s performance data—such as RPM, throttle position, boost pressure, and more—during specific driving conditions. These logs help your tuner understand how your car is running and what changes may be needed to improve performance.
Data logs can be created using either the TDN App (mobile method) or VCM Suite Beta (laptop method). During the tuning process, your tuner will request specific types of logs, like a 3rd or 4th gear pull at wide open throttle (WOT). You may also record and submit logs to show how your vehicle responds to previous tune changes or to request new adjustments.
An info log is a diagnostic file that captures operational data from your tuning hardware and software, and from your vehicle.
These are generated automatically when a user clicks the "Gather Info Log" option from the Tools Menu in the TDN App, or the blue "i" icon in VCM Suite. Users must then share the info log via email or screenshot.
Info logs are useful for identifying potential causes of error and should be included any time technical support is requested.
MPVI devices (such as MPVI2+, MPVI3, MPVI4) are tuning tools from HP Tuners. They connect to your vehicle’s OBD2 port and allow you to read, write, and log data using HP Tuners software (VCM Suite Beta - laptop, or TDN App - mobile).
Compatibility of MPVI with specific vehicles varies by generation.
MPVI devices are also capable of editing unlocked tunes, which does not apply to ZFG Custom Tunes since they are locked.
A full-throttle acceleration in a specific gear, used to gather performance data. Commonly requested during the tuning process to assess engine behavior under load.
In most cases, reaching the requested gear is achieved by manually downshifting. Specific RPM within a gear can be achieved by letting off the throttle or applying more throttle.
In vehicles without manual mode or paddle shifters, you can reach a requested gear by applying throttle selectively.
Please note: The gear will automatically change if RPM rise too high or too low once a gear is manually commanded.
A measurement of how many times an object rotates a full 360 degrees in one minute.
In the context of an engine, RPM measures the number of times the crankshaft completes a full rotation in a minute. This is a key indicator of engine speed and is used in conjunction with gears to determine vehicle performance.
RTD devices (such as RTD+, RTD3, and RTD4) are tuning tools created by HP Tuners. They connect to your vehicle’s OBD2 port and allow you to read, write, and log data using HP Tuners software (VCM Suite Beta - laptop, or TDN App - mobile).
Compatibility of RTD with specific vehicles varies by generation.
This is your vehicle’s original factory tune. You read this file using your tuning hardware. It’s used to build your baseline and custom tunes.
When your stock calibration is read via TDN App, a copy is stored for you to access and flash at any time. This file typically appears as "Restore" on the TDN App.
When your stock calibration is read via VCM Suite Beta, a copy of the resulting file should be stored in a secure location in case you'd like to flash back to it in the future.
A tune tequest is required every time your tune needs action.
These serve as placeholders in our "queue" and are processed in the order received.
All tune requests are submitted in Tuning Central on the ZFG website or in the ZFG App.
Tune requests...
Notify your tuner that a file has been synced to the TDN App and is pending review.
Provide a place to attach files from VCM Suite in addition to other relevant sources such as Dragy.
Define and share your goals, questions, tuning preferences, contact information, and more.
Ask questions about your tune(s) or plans for the vehicle.
Get feedback directly from our tuner.
In context of the initial tuning process:
Each time your tuner reviews a data log and makes changes, you receive a new version of your tune - a tune revision.
Tune revisions are typically labeled in sequence such as "Rev01" and "Rev02". Their titles may include other identifying information such as VIN, fuel type, and tuning goal.
In context of future needs:
Changes or adjustments made to a completed tune also constitute "tune revisions."
The sequential numbering of these revisions usually follows the sequence of previous revisions. For example, if your completed tune was Rev02, then your next tune revision will be Rev03.
This is ZFG Racing’s portal or hub for all tune-related needs.
It’s the main way to communicate with your tuner. Everything submitted here goes directly to your tuner for review, in order of receipt.
It's where you'll...
Submit Tune Requests
Access instructions for tuning
Find software such as VCM Suite Beta
View Tuning Central at this link.
A software package from HP Tuners used for laptop-based tuning. It includes VCM Editor and VCM Scanner, and may required for reading, writing, and logging your vehicle’s data. This software package is typically required for MPVI devices that are not TDN-compatible.
Additionally, your tuner may request that you use this software instead of the TDN App for data logging in some circumstances.