{"product_id":"spark-exhaust-db-killer-grid-o-45mm","title":"Spark Exhaust dB Killer Grid-O 45 mm Open Universal G9988","description":"\u003cp\u003eForty-five millimetres through a fifty-one and a half millimetre body. There is barely a wall left — which is exactly the point of this article.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003edB killer for Spark Grid-O silencers.\u003c\/li\u003e\n\u003cli\u003eØ 51.5 mm outer, 45 mm internal bore.\u003c\/li\u003e\n\u003cli\u003eOpen type, no perforation.\u003c\/li\u003e\n\u003cli\u003eThe widest and least restrictive of Spark's four Grid-O inserts.\u003c\/li\u003e\n\u003cli\u003eStainless steel, removable.\u003c\/li\u003e\n\u003cli\u003eSpark part number G9988, made in Mantova, Italy.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eThree Millimetres of Wall\u003c\/h2\u003e\u003cp\u003eForty-five inside a fifty-one and a half body leaves about three millimetres all round. That is as little restriction as an insert can offer while still being an insert, and it is why this one costs sixty euro: a thin section in stainless takes more care to make than a thick one.\u003c\/p\u003e\u003ch2\u003eWho Needs the Widest One\u003c\/h2\u003e\u003cp\u003eLarge-capacity machines, and venues whose limits are generous. On a big four or a large V-twin the narrower Grid-O inserts cost real mid-range, and if the machine only needs two or three decibels shaved off, the 45 does it without the penalty.\u003c\/p\u003e\u003cp\u003eIt is also the sensible first purchase if you do not yet know how far over the limit you are. Start wide, measure, go narrower if you must.\u003c\/p\u003e\u003ch2\u003eThe Family Ladder\u003c\/h2\u003e\u003cp\u003e32, 38, 40, 45. Four bores, one body, one silencer family. Owners who run the same machine at different circuits sometimes carry two of the four; the swap takes minutes and needs a screwdriver.\u003c\/p\u003e\u003ch2\u003eWhy All Four Are Open\u003c\/h2\u003e\u003cp\u003eBecause the Grid-O ends in a woven titanium mesh across the whole outlet, and the mesh is already doing acoustic work. A perforated insert behind it would restrict without adding much attenuation, so Spark builds all four as plain bores.\u003c\/p\u003e\u003ch2\u003eSixty Euro, and Why\u003c\/h2\u003e\u003cp\u003eThe most expensive of the four Grid-O inserts, because it is the hardest to make. A three-millimetre wall in stainless has to be machined and finished without distorting, and there is less material to hold while that happens.\u003c\/p\u003e\u003ch2\u003eOrdering\u003c\/h2\u003e\u003cp\u003eOne per silencer. If the case came to you without an insert, send us the exhaust's article number rather than guessing — the four look identical from outside and only the bore separates them.\u003c\/p\u003e\u003ch2\u003eApproval\u003c\/h2\u003e\u003cp\u003eUnaffected. A racing Grid-O stays a racing article with any insert fitted, and a homologated exhaust belongs in the configuration Spark tested it in.\u003c\/p\u003e","brand":"Spark Exhaust","offers":[{"title":"Default Title","offer_id":53617783505162,"sku":"G9988","price":33700.0,"currency_code":"XOF","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7831\/0410\/files\/69f8abc19f203_e4efc8de-ace4-45dc-b025-b33e35f849c6.png?v=1788354100","url":"https:\/\/inter-pace.com\/en-ci\/products\/spark-exhaust-db-killer-grid-o-45mm","provider":"Inter-Pace","version":"1.0","type":"link"}