{"product_id":"polarstar-fusion-engine-drop-in-kit-gen3-v2-m4-m16-uk-spec-red-low-flow-poppet-red-nozzle","title":"Polarstar Fusion Engine Drop-in Kit GEN3 — V2 (M4\/M16) — UK Spec (Red Low-Flow Poppet, Red Nozzle)","description":"\u003cdiv style=\"background:#edfaf1;border-left:4px solid #27ae60;padding:12px 16px;border-radius:0 6px 6px 0;margin:0 0 16px;font-size:13px;\"\u003e\n\u003cstrong style=\"color:#1a6b3a;\"\u003ePolarstar Fusion Engine Drop-in Kit GEN3 — V2 (M4\/M16) — UK Spec (Red Low-Flow Poppet, Red Nozzle) — \u003c\/strong\u003e Polarstar Fusion Engine Drop-in Kit GEN3 for V2 (M4\/M16) gearboxes — pre-configured with the Red Low-Flow Poppet and Red Nozzle for UK site limits. The original HPA system that started the category in 2011, still the benchmark for adjustability.\u003c\/div\u003e\n\u003cp\u003eThe Fusion Engine launched in 2011 as the first new HPA system in over two decades and won Popular Airsoft's Best HPA Engine award the very first year the category existed. Most other engines on the market trace their lineage back to ideas the Fusion pioneered: dual-solenoid control, full CNC aluminium chassis replacing the entire gearbox, FCU-controlled fire modes, and adjustable poppet\/nozzle restrictors for velocity tuning.\u003c\/p\u003e\n\u003cp\u003eThis V2 GEN3 kit is configured specifically for UK site limits. The Red Low-Flow Poppet restricts the firing air volume to bring velocity down into legal territory while keeping the engine's response time and ROF intact. The Red Nozzle is matched to the poppet for consistent behaviour at lower pressures. If you ever take the rifle abroad to a higher-energy site, swapping to a less-restrictive poppet\/nozzle combination raises the velocity ceiling without any other build changes — the Fusion has 6 colour-coded nozzle options that shift the adjustment range in large increments.\u003c\/p\u003e\n\u003cp\u003eWhere the Fusion still wins against newer engines is the breadth of adjustment in a single build. Maximum cyclic ROF is 30+ RPS in standard configurations. Adjustable velocity, independently adjustable poppet (firing air) and nozzle (feeding), and a full closed-bolt firing cycle for maximum accuracy. The closed-bolt design also makes it less sensitive to hop-up configuration than open-bolt engines, so existing AEG hop chambers and inner barrels typically just work.\u003c\/p\u003e\n\u003cp\u003eThe kit ships as a complete drop-in: lightweight CNC aluminium chassis, FCU, switchboard, wire harness, and all the platform-specific components needed for V2 M4\/M16 installation. It's a full replacement for your AEG gearbox — gears, piston, motor, the lot — so no leaking cylinders, no stripped gears, no broken pistons. A 7.4V to 9.6V LiPo or NiMH battery is needed for the FCU (not included).\u003c\/p\u003e\n\u003ch2 style=\"font-size:16px;color:#1B3A6B;margin:18px 0 8px;\"\u003eSpecifications\u003c\/h2\u003e\n\u003ctable style=\"width:100%;border-collapse:collapse;font-size:13px;margin:0 0 18px;\"\u003e\n\u003ctr style=\"background:#1B3A6B;color:#fff;\"\u003e\n\u003cth style=\"padding:7px 12px;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"padding:7px 12px;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eEngine\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003ePolarstar Fusion Engine GEN3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eConfiguration\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eUK spec — Red Low-Flow Poppet + Red Nozzle pre-installed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003ePlatform\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eV2 gearbox AEG (M4 \/ AR-15 style)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eChassis\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eFull CNC-machined aluminium — complete gearbox replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eFiring cycle\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eClosed-bolt (highest accuracy)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eVelocity (test data)\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003e550 FPS @ 0.20g @ 120 PSI with Black Poppet \/ Blue Nozzle \/ 6.05 × 375mm barrel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eVelocity range\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eWidest of any Polarstar engine — 6 nozzle colours for large adjustments\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eRate of fire\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003e30+ RPS achievable in most configurations\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eAir efficiency\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003e~400+ shots from 13ci\/3000 PSI tank @ 1.5J on 0.28g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eHop-up compatibility\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eWorks with standard AEG hop chambers and inner barrels\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eMag compatibility\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eTokyo Marui-compatible M4\/M16 AEG magazines (mid-caps, hi-caps, low-caps)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eIn the kit\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eEngine, FCU, switchboard, wire harness, V2 install components\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003ePower\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003e7.4–9.6V LiPo or NiMH for FCU (not included), HPA tank + regulator separate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003cdiv style=\"background:#1B3A6B;color:#fff;padding:12px 16px;border-radius:6px;margin:18px 0 0;font-size:13px;\"\u003e\n\u003cstrong style=\"color:#fff;\"\u003e💡 Titan Forge Airsoft tip:\u003c\/strong\u003e The Fusion is still favoured by long-time HPA technicians for its breadth of adjustment and field-proven reliability — if you've owned an HPA rifle before and want maximum tuning headroom, this is the engine to choose. New to HPA? The \u003ca href=\"\/products\/polarstar-f2-hpa-engine-bundle\" style=\"color:#cdd6f4;\"\u003eF2 Bundle\u003c\/a\u003e is smaller, lighter, and more air-efficient. Browse \u003ca href=\"\/collections\/hpa-engines\" style=\"color:#cdd6f4;\"\u003eour full engine range\u003c\/a\u003e for comparison.\u003c\/div\u003e","brand":"Polarstar","offers":[{"title":"Default Title","offer_id":55566073201016,"sku":"3264397133","price":499.95,"currency_code":"GBP","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0562\/8097\/3450\/files\/PolarstarFusionEngineDrop-inKitGEN3-TitanForgeAirsoft-1.webp?v=1779266933","url":"https:\/\/www.titanforgeairsoft.com\/products\/polarstar-fusion-engine-drop-in-kit-gen3-v2-m4-m16-uk-spec-red-low-flow-poppet-red-nozzle","provider":"Titan Forge Airsoft","version":"1.0","type":"link"}