{"product_id":"spark-exhaust-stainless-tube-70mm-500mm","title":"Spark Exhaust Stainless Steel Tube Ø 70 × 1.2 mm 500 mm Universal G9009","description":"\u003cp\u003eSeventy millimetres, and the first step up in wall thickness since the twenty-eight. At this size a tube stops being a pipe and starts being a body.\u003c\/p\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eStraight exhaust tube, AISI 304 stainless steel.\u003c\/li\u003e\n\u003cli\u003eØ 70 mm outside, 1.2 mm wall thickness.\u003c\/li\u003e\n\u003cli\u003e500 mm long.\u003c\/li\u003e\n\u003cli\u003eThicker wall than the 32 to 60 mm sizes.\u003c\/li\u003e\n\u003cli\u003eSpark part number G9009, made in Mantova, Italy.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eWhy 1.2 mm Here\u003c\/h2\u003e\u003cp\u003eA one millimetre wall is entirely adequate for stiffness at seventy millimetres. What it is not adequate for is noise: a large-diameter thin tube radiates sound through its own wall, and past sixty millimetres that becomes audible as a metallic ring layered over the exhaust note.\u003c\/p\u003e\u003cp\u003eTwo tenths of a millimetre of extra wall raises the panel's natural frequency and damps it. It is a small change with a disproportionate effect.\u003c\/p\u003e\u003ch2\u003eWhat Gets Built From It\u003c\/h2\u003e\u003cp\u003eSilencer bodies, pre-silencer boxes, expansion sections and the large-volume chambers that a custom system uses to control noise without a restriction. Seventy millimetres is rarely a gas path in its own right — it is the shell around one.\u003c\/p\u003e\u003ch2\u003eRolling an End\u003c\/h2\u003e\u003cp\u003eIf you are making a silencer body, the ends have to close. That means either a spun cap, a rolled edge or a machined end ring, and all three are easier at 1.2 mm than at 1.0: thicker material tolerates being worked without splitting.\u003c\/p\u003e\u003ch2\u003eWeight Goes Up Fast\u003c\/h2\u003e\u003cp\u003eA 500 mm length at 70 × 1.2 weighs close to a kilogram. Diameter and wall both count, and at this end of the range the material becomes a real part of the finished weight rather than a rounding error.\u003c\/p\u003e\u003ch2\u003eBends\u003c\/h2\u003e\u003cp\u003eSpark bends this diameter at 30°, 45° and 90°. Bending 70 mm at home is not realistic without proper tooling; the wall will collapse on the inside of the radius long before the tube reaches the angle.\u003c\/p\u003e\u003ch2\u003ePerforated Core, Separately\u003c\/h2\u003e\u003cp\u003eA silencer body built from this tube needs a perforated inner tube and packing to be a silencer rather than a resonator. Spark does not sell either as a catalogue article, so plan that part of the build around what your workshop can source — the outer shell is the easy half.\u003c\/p\u003e\u003ch2\u003eOrdering\u003c\/h2\u003e\u003cp\u003eOne 500 mm length per article, supplied uncut.\u003c\/p\u003e","brand":"Spark Exhaust","offers":[{"title":"Default Title","offer_id":53617861689610,"sku":"G9009","price":33.77,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0949\/7831\/0410\/files\/65c4e5324c987_2bae6bd3-57d8-41be-8271-c8b013a01c66.png?v=1788362744","url":"https:\/\/inter-pace.com\/en-cl\/products\/spark-exhaust-stainless-tube-70mm-500mm","provider":"Inter-Pace","version":"1.0","type":"link"}