The D22 Navara YD25 is fitted from factory with a wastegated turbocharger. While reliable and simple, the wastegated setup offers a narrower usable power band compared to modern VNT (Variable Nozzle Turbo) systems.
Upgrading the turbo is one of the most effective ways to improve drivability and increase power potential on the YD25 platform.
Factory Wastegated Turbo
The factory turbo is mechanically controlled and responds predictably. For mild builds, there are several direct bolt-on high-flow options available that:
- Increase airflow over stock
- Support moderate tuning
- Improve top-end performance
These are suitable for basic performance upgrades while retaining the simplicity of the wastegated system.
However, the power delivery remains relatively linear and does not dramatically broaden the torque curve.
Upgrading to a D40 YD25 VNT Turbo (Recommended Upgrade Path)
A more substantial and worthwhile upgrade is converting to a VNT turbo from the D40 Navara YD25.
This conversion provides:
- Faster spool
- Stronger low-RPM torque
- Wider and more usable torque band
- Improved drivability
- Greater overall performance flexibility
Important: Use the “Standard Output” D40 Setup
When performing this upgrade, it is recommended to use the standard output D40 YD25 VNT turbo.
The “high output” D40 version uses an electronic VNT actuator, which adds complexity and requires more advanced integration to function correctly.
The standard output version uses a vacuum-actuated VNT system, which is much easier to integrate into the D22 platform.
What Is Required for the Conversion?
To complete the D40 VNT conversion, you will typically need:
- D40 exhaust manifold
- D40 standard output VNT turbocharger
- Appropriate oil feed and return lines
- Custom or modified dump pipe
- Aftermarket boost control solution
Because the D22 does not have factory VNT control strategies, an aftermarket boost control system is required, such as:
- Tillix kit
- Dawes valve
- HPD VNT controller
- Similar mechanical or electronic VNT control solutions
Proper tuning is essential after conversion.
Benefits of the VNT Conversion
Compared to the factory wastegated setup, the VNT turbo provides:
- Stronger low-end response
- Broader torque curve
- More usable mid-range power
- Better towing performance
- Improved drivability
For daily driving and touring applications, the improvement in response and flexibility is often more noticeable than peak power alone.
Aftermarket Support and Future Upgrades
Converting to a VNT setup also opens up significantly more options in the aftermarket.
Once on a VNT platform, you gain access to:
- Larger performance VNT turbos
- High-flow VNT upgrades
- Broader turbo sizing options
This creates a stronger pathway for higher power builds compared to remaining on a wastegated system.
Summary
- Factory turbo is wastegated
- Direct bolt-on high-flow upgrades are available
- Converting to a D40 standard output VNT turbo is the preferred upgrade path
- High output D40 electronic actuator versions are not recommended for simple swaps
- Manifold, turbo, oil lines, and custom dump pipe are required
- Aftermarket boost control is necessary
- VNT conversion opens up greater future upgrade potential
For the D22 YD25, the VNT conversion is often the best balance between drivability, torque improvement, and future performance potential.