{"product_id":"arrow-71860ak","title":"Arrow Thunder Aluminium Slip-On Silencer KTM RC 390 (2017-2020) 71860AK","description":"\u003cp\u003eThe Arrow Thunder 71860AK is a road-legal slip-on silencer engineered for everyday riders who want a genuine upgrade without compromise. Weighing just 2.03 kg and carrying a full E-number type approval, it slots neatly into the daily commute or weekend canyon run while noticeably sharpening throttle response on the KTM RC 390.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eLightweight aluminium canister at 2.03 kg keeps unsprung mass low and improves throttle response\u003c\/li\u003e\n\u003cli\u003eE-number road approval means no MOT worries or insurance headaches — ride it straight from the box\u003c\/li\u003e\n\u003cli\u003eIntegrated DB killer keeps sound levels within legal limits for everyday street use, removable for track days\u003c\/li\u003e\n\u003cli\u003eCarbon end cap adds a motorsport finish without the full-carbon price premium\u003c\/li\u003e\n\u003cli\u003eStainless steel internals resist heat and corrosion for long-term reliability\u003c\/li\u003e\n\u003cli\u003eCan be paired with an Arrow header to form a full exhaust system for further gains\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eBuild Quality\u003c\/h2\u003e\u003cp\u003eArrow has constructed the Thunder canister from aerospace-grade aluminium, a material chosen for its combination of rigidity and low weight rather than simple cost-cutting. The 270 mm body handles the thermal cycling of spirited street riding without warping or discolouring. Internal components are fabricated from stainless steel, ensuring consistent flow characteristics and resistance to the condensation that shortens the life of cheaper alternatives. The carbon end cap is not a cosmetic stick-on but a structural part of the outlet assembly, adding durability where heat and vibration are at their most intense.\u003c\/p\u003e\u003ch2\u003ePerformance on the Road\u003c\/h2\u003e\u003cp\u003eWith a 54 mm inlet diameter and a 50 mm outlet, the Thunder is sized to complement the RC 390 single-cylinder's natural power band rather than simply evacuate exhaust gases faster. The result is a broader spread of mid-range torque that suits real-world riding — overtaking on A-roads, filtering in traffic, and carrying corner speed on track days alike. The DB killer ships fitted as standard, satisfying noise regulations without permanently strangling the exhaust note; removing it for private track use takes minutes.\u003c\/p\u003e\u003ch2\u003eFitment \u0026amp; Compatibility\u003c\/h2\u003e\u003cp\u003eThis slip-on is a direct replacement for the standard silencer on the following model:\u003c\/p\u003e\u003cul\u003e\u003cli\u003eKTM RC 390 — model years 2017, 2018, 2019, 2020\u003c\/li\u003e\u003c\/ul\u003e\u003cp\u003eInstallation requires the Arrow connecting pipe 71667MI (sold separately). Without this link pipe the slip-on will not fit the OEM header. For a full exhaust conversion, the 71860AK can be combined with an Arrow header to replace the entire system from the cylinder head back.\u003c\/p\u003e\u003cp\u003ePlease note: the primary product image has been composited for illustrative purposes as Arrow had not released a dedicated photograph for the RC 390 fitment at the time of listing. The product itself is exactly as described here and carries the full Arrow specification for part number 71860AK.\u003c\/p\u003e\u003ch2\u003eSpecifications\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003ePart number: 71860AK\u003c\/li\u003e\n\u003cli\u003eWeight: 2.03 kg\u003c\/li\u003e\n\u003cli\u003eCanister material: aluminium\u003c\/li\u003e\n\u003cli\u003eEnd cap material: carbon\u003c\/li\u003e\n\u003cli\u003eInternal components: stainless steel\u003c\/li\u003e\n\u003cli\u003eCanister length: 270 mm\u003c\/li\u003e\n\u003cli\u003eInlet diameter: 54 mm\u003c\/li\u003e\n\u003cli\u003eOutlet diameter: 50 mm\u003c\/li\u003e\n\u003cli\u003eRoad approval: E-number type approved\u003c\/li\u003e\n\u003cli\u003eDB killer: included (fitted as standard)\u003c\/li\u003e\n\u003cli\u003eRequired link pipe: Arrow 71667MI (sold separately)\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Arrow","offers":[{"title":"Default Title","offer_id":53168798400778,"sku":"71860AK","price":346.29,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7831\/0410\/files\/71860AKfff.png?v=1780815710","url":"https:\/\/inter-pace.com\/pt\/products\/arrow-71860ak","provider":"Inter-Pace","version":"1.0","type":"link"}