Low Stock
Jack Engine 1
Jack Engine 2
Jack Engine 1Jack Engine 2

PolarStar JACK HPA Engine Conversion Kit – Programmable High-Performance AEG Upgrade

$274.99

Upgrade your AEG with the PolarStar JACK HPA Engine Conversion Kit, featuring programmable fire modes, instant trigger response, adjustable velocity, and reliable single-moving-part operation. This efficient, high-performance HPA system is ideal for CQB, outdoor play, and competitive airsoft builds.

Order today for same-day fulfillment • Estimated delivery Oct 3–4
  • Secure Checkout
  • SHIPS SAME DAY
  • 14 DAY RETURNS

Benefits:

  • Instant HPA Trigger Response Instant HPA Trigger Response
  • Programmable Fire Modes Programmable Fire Modes
  • Adjustable FPS and Rate of Fire Adjustable FPS and Rate of Fire
  • Efficient, Low-Maintenance Design Efficient, Low-Maintenance Design
  • Broad AEG Gearbox Compatibility Broad AEG Gearbox Compatibility

Frequently Bought Together

Complete your setup with the most common add-ons.

PolarStar Fusion Engine Nozzle for M4/M16

$22.99

PolarStar HopUp “Thing” TDC Chamber for V2 M4 AEG & HPA Rifles

$69.99

PolarStar Complete O-Ring and Screw Set for JACK (MP7 Excluded)

$7.99

PolarStar Heavy Poppet Spring for FE/F2

$2.99

PolarStar Light Poppet Spring for FE/F2

$3.49

PolarStar JACK HPA Engine Conversion Kit

Upgrade your AEG with the PolarStar JACK HPA Engine, an affordable electro-pneumatic conversion system engineered for fast trigger response, adjustable performance, reliable operation, and simplified maintenance.

Product Overview

The PolarStar JACK replaces your AEG’s mechanical gearbox components with a programmable HPA system. Its compact drop-in cylinder design uses only one moving component—the nozzle, which also functions as the poppet valve. This streamlined construction delivers strong airflow, rapid response, consistent shooting, and dependable operation with fewer wear-prone parts.

Velocity is adjusted through input pressure and FCU settings, allowing the JACK to accommodate CQB, outdoor, and competitive airsoft requirements. In a standard M4 configuration, PolarStar reports adjustment from below 280 FPS to approximately 500 FPS with 0.20g BBs, depending on barrel length, bore, pressure, and tuning.

Features & Benefits

  • Programmable semi-auto, full-auto, and burst fire modes

  • Instant trigger response with adjustable rate of fire

  • Up to approximately 30 rounds per second

  • Efficient design capable of 1,000+ shots from a 13/3000 tank

  • Easy velocity adjustment without changing nozzles

  • Durable, low-maintenance single-moving-part design

  • Filter fitting helps protect the internal HPA system

Specifications

  • System: Electro-pneumatic HPA engine

  • Maximum Velocity: Approximately 500 FPS at 130 PSI with 0.20g BBs

  • Maximum Rate of Fire: Approximately 30 RPS

  • Fire Control: Programmable FCU

  • Manufacturer: PolarStar Airsoft

Compatibility

Available for multiple center-line-nozzle gearbox platforms, including V2 M4/M16, V3 AK, M249, ARES, VFC HK417/G28, TAR-21, KAC LMG, and M60 configurations. Select the correct model for your replica.

What’s Included

JACK HPA engine, installed filter fitting, FCU, switchboard, wiring harness, and model-specific conversion components. HPA tank, regulator, air line, and FCU battery are sold separately.

Installation

Gearbox disassembly, engine alignment, FCU setup, and performance tuning are required. Professional installation is recommended for optimal reliability and air-seal performance.

Common Product Questions

Find quick answers about our airsoft products, shipping and policies.

Can LA Airsoft install this part for me?

Yes. We can build and upgrade Hi-Capas, AAP platforms, and rifles. Choose your base gun and parts, then add the appropriate tech service.

The current custom-build service states that builds are normally completed in approximately 3 to 5 days, with the team reviewing the selected parts for compatibility.

Do I need tools or gunsmithing?

That depends on the upgrade. Simple external parts may be straightforward, but internal upgrades can require disassembly, reassembly, adjustment and testing.

If you are not comfortable working inside your airsoft gun, our team offers professional tech and custom-build services.

How quickly will my order ship?

Orders without preorder items are typically packed the same day when placed before 4:30 p.m. Central Time. Please note that occasional delays can occur during especially busy periods or when staffing is limited.

How should I maintain this product?

Regular maintenance helps preserve performance and reliability. Keep the product clean, follow the manufacturer’s lubrication instructions, and properly manage batteries, gas systems, and internal components. More advanced repairs or internal servicing should be handled by an experienced airsoft technician.

Will this part fit my platform?

Compatibility is product-specific. Check the brand, model, size, and platform named in the product description, such as Tokyo Marui Hi-Capa 4.3 or 5.1, AAP-01, Umarex/VFC Glock, or a particular AEG gearbox type.

Similar-looking parts are not always interchangeable, so contact our team with your exact model if you are unsure.

Will this part increase my FPS?

Not every upgrade increases FPS. Some parts are designed primarily for reliability, cycling speed, weight reduction, or gas efficiency. When a product has a tested FPS claim, it should be stated in the listing.