Pre-Order ETA November 2026

ARES HPA ENGINE FOR AIRSOFT M4 V2 GEARBOXES

Single-Sided Selector • CNC Aluminum • EFCS • Adjustable ROF & Trigger • V2 M4 Compatibility

AEG TO HPA CONVERSION // CNC ALUMINUM ENGINE // ELECTRONIC FIRE CONTROL // TUNABLE PERFORMANCE

Transform a compatible M4 AEG into a dedicated HPA platform with the ARES HPA Engine for Airsoft M4 V2 Gearboxes – Single-Sided Selector.

Designed as a complete drop-in HPA conversion system for compatible Tokyo Marui and ARES-spec Version 2 M4 gearboxes, the ARES engine replaces the traditional mechanical AEG power system with a precisely controlled pneumatic setup.

Featuring CNC aluminum construction, Electronic Fire Control System (EFCS), adjustable trigger sensitivity, adjustable rate of fire, semi and full-auto modes, and an operating pressure range of approximately 4–12 BAR, the ARES HPA Engine gives experienced airsoft players a highly tunable foundation for custom HPA builds.

01 // COMPLETE V2 AEG TO HPA CONVERSION

The ARES HPA Engine is designed to replace the conventional components responsible for firing a compatible Version 2 AEG.

Instead of relying on a motor, gears, piston, and main spring to generate each shot, the HPA engine uses regulated compressed gas and electronically controlled operation.

This provides the foundation for the characteristics that make HPA systems so popular: consistent output, responsive operation, reduced mechanical complexity, and extensive tuning capability.

The system is intended for compatible M4 platforms using Tokyo Marui or ARES-spec Version 2 gearbox architecture.

Fitment should always be confirmed before installation, particularly with heavily modified or non-standard receivers and gearboxes.

02 // CNC ALUMINUM CONSTRUCTION

At the heart of the ARES system is a CNC-machined aluminum housing.

The lightweight metal construction provides a durable foundation for the engine while avoiding unnecessary weight inside the rifle.

Because an HPA engine eliminates many of the traditional moving components found in an AEG drivetrain, the internal operating system is significantly different from a conventional gearbox.

The streamlined design helps reduce the mechanical wear associated with gears, pistons, and high-speed motors while creating a strong platform for long-term HPA use when correctly installed and maintained.

03 // ELECTRONIC FIRE CONTROL SYSTEM

The ARES HPA Engine incorporates an Electronic Fire Control System (EFCS) to manage trigger input and firing operation.

Electronic control provides a precise interface between the trigger and HPA engine, allowing the system to deliver responsive and consistent operation.

The engine supports both semi-automatic and full-automatic firing modes, giving players flexibility for different airsoft environments where those firing modes are permitted.

This single-sided-selector model is specifically configured for compatible M4 builds using the appropriate selector arrangement.

04 // ADJUSTABLE TRIGGER SENSITIVITY

Trigger feel can make a major difference in an HPA build.

The ARES system allows trigger sensitivity to be adjusted, giving players the ability to fine-tune how the engine responds to trigger input.

This makes the platform adaptable to different playing styles, from players who prefer a conventional trigger response to builds focused on faster, more responsive operation.

Adjustments should always be made gradually.

Extreme settings can lead to irregular cycling or inconsistent operation, so small incremental changes are recommended when tuning the system.

05 // ADJUSTABLE RATE OF FIRE

The electronic system also provides adjustable rate-of-fire (ROF) control.

This allows the firing characteristics to be configured around the player’s needs and field requirements rather than being dictated by a traditional motor-and-gear combination.

The ability to electronically tune ROF is one of the major advantages of an HPA conversion for players who enjoy optimizing their equipment.

Always configure firing modes and rate of fire within the rules established by your local airsoft field.

06 // TUNABLE OPERATING PRESSURE

The ARES HPA Engine is designed around an adjustable operating pressure range of approximately 4–12 BAR, or roughly 58–174 PSI at the engine specification level.

However, the pressure delivered by your airsoft HPA regulator must always remain within the safe operating limits specified for the complete system and its individual components.

The supplied safety guidance specifically states:

Never raise regulated supply pressure above 120 PSI.

More pressure should never be treated as automatically meaning better performance. Correct HPA tuning involves balancing operating pressure, system settings, barrel configuration, BB weight, and field velocity requirements.

07 // HIGH AIR EFFICIENCY

Efficient use of air is one of the key goals of a well-designed HPA system.

The ARES engine is optimized to provide consistent output while reducing unnecessary air consumption, helping players make better use of their available tank capacity.

Actual efficiency will depend on the rifle configuration, pressure setting, electronic tuning, barrel setup, firing habits, and environmental conditions.

Careful tuning is therefore important when building an efficient and consistent HPA platform.

08 // 11.1V LIPO POWERED ELECTRONICS

Although compressed air provides the energy used to fire the BB, the ARES engine still requires a battery to power its electronic control system.

The electronics are designed to operate using an 11.1V LiPo battery.

Depending on the specific version, the electronic connection may use T-Dean or XT30, so always verify the connector supplied with your exact engine before selecting a battery.

The battery powers the electronics—it does not replace the external regulated air source required for HPA operation.

WHY CHOOSE THE ARES HPA ENGINE?

✓ COMPLETE HPA CONVERSION

Designed to convert a compatible Version 2 M4 AEG gearbox platform to HPA operation.

✓ CNC ALUMINUM CONSTRUCTION

Lightweight and durable housing provides a solid foundation for a custom build.

✓ EFCS ELECTRONICS

Electronic fire control manages trigger input and firing operation.

✓ ADJUSTABLE TRIGGER

Fine-tune trigger sensitivity around your preferred response.

✓ ADJUSTABLE ROF

Electronic rate-of-fire adjustment provides additional control over the rifle’s setup.

✓ SEMI + FULL AUTO

Supports multiple firing modes where permitted.

✓ HIGH AIR EFFICIENCY

Designed to deliver consistent operation while minimizing unnecessary air consumption.

✓ V2 M4 COMPATIBILITY

Built around compatible Tokyo Marui and ARES-spec Version 2 M4 platforms.

Is professional installation recommended?

HPA conversions require correct fitment, air-system setup, electronic configuration, and chronograph testing. If you are unfamiliar with HPA installation, having the engine installed and tuned by a qualified airsoft technician is strongly recommended.

TUNING NOTICE // SMALL ADJUSTMENTS MATTER

The ARES HPA Engine is mechanically and electronically adjustable.

Extreme settings can negatively affect performance and may result in irregular cycling.

For best results, adjustments should be made in small, incremental steps, with the rifle tested after each change until a reliable balance between responsiveness, consistency, and stability is achieved.

Always chronograph the rifle after performance adjustments and remain within your field’s FPS and joule limits.

⚠ HPA SAFETY // HIGH-PRESSURE AIR REQUIRES PROPER HANDLING

HPA equipment stores compressed gas at very high pressure and requires appropriate equipment, inspection, and handling.

Never introduce oil into an HPA tank fill valve.

Only have HPA tanks filled by properly trained personnel using suitable equipment. Keep the tank protected from impacts and securely stored during transportation.

Follow the tank manufacturer’s hydrostatic testing requirements and expiration dates.

Always use a properly rated airsoft regulator and compatible air line, and never exceed the safe pressure rating of the lowest-rated component in your system.

When finished playing, follow the equipment manufacturer’s procedure for safely shutting down and depressurizing the system.

FINAL WORD // TAKE CONTROL OF YOUR HPA BUILD

The ARES HPA Engine for Airsoft M4 V2 Gearboxes – Single-Sided Selector gives experienced builders a highly tunable foundation for converting a compatible M4 AEG to HPA.

With its CNC aluminum construction, EFCS electronic control, adjustable trigger sensitivity, adjustable rate of fire, semi/full-auto capability, efficient pneumatic operation, 11.1V LiPo-powered electronics, and V2 M4 compatibility, the ARES engine provides the flexibility needed for everything from responsive competitive builds to carefully tuned field rifles.

Build it correctly. Tune it carefully. Chronograph it for your field.

ARES HPA // EFCS CONTROL // V2 M4 COMPATIBILITY // TUNED YOUR WAY