{"product_id":"bmw-s85-e60-m5-e63-m6-100-equal-length-headers","title":"BMW S85 E60 M5 \/ E63 M6 100% Equal Length Headers","description":"\u003cp\u003eThe V4 Equal Length Header continues from the worldwide success of the V3, designed using 3D scans of the engine and engine bay in CAD to achieve the most efficient possible layout. Designed and built in-house at Infinity Design's own facility.\u003c\/p\u003e\u003cp\u003eWhere the V3 was close to equal length, the V4 primaries are now 100% equal length, giving a marginally smoother tone. The larger overall volume benefits stock engines, bolt-on builds and larger-displacement 5.5L–5.8L engines alike. Each primary has a 730 mm centre-radius length and steps from 42 mm up to 45 mm near the collector, feeding an enlarged F1-style slip-on collector built from 45 mm pipework.\u003c\/p\u003e\u003cp\u003eCNC-machined flanges taper internally from the oval cylinder-head ports to the 42 mm primary O.D. for a smooth transition, joined with full-penetration argon-purged welds. Fitment and head-stud access have been improved, with all nuts reachable using normal workshop tools when the primary fitting sequence is followed.\u003c\/p\u003e\u003cp\u003ePlease allow approximately a 6-week lead time, as each header is manufactured to order at the Infinity Design facility.\u003c\/p\u003e\u003ch3\u003ePerformance Testing\u003c\/h3\u003e\u003cp\u003eThe V3 consistently gained 30–40 hp on many cars worldwide on independent dynamometers; no additional power is expected from the V4, which focuses on perfecting equal-length geometry, volume and fitment. An ECU tune is required.\u003c\/p\u003e\u003ch3\u003eFeatures\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e+30–50 hp with a supporting tune (V3-proven gains)\u003c\/li\u003e\n\u003cli\u003e100% T304 stainless steel construction\u003c\/li\u003e\n\u003cli\u003e100% equal-length stepped primary design (42 mm → 45 mm)\u003c\/li\u003e\n\u003cli\u003e730 mm centre-radius primaries with enlarged F1-style collector\u003c\/li\u003e\n\u003cli\u003eCNC-machined internally tapered flanges\u003c\/li\u003e\n\u003cli\u003eFull-penetration argon-purged welds\u003c\/li\u003e\n\u003cli\u003eECU tune required\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Infinity Design","offers":[{"title":"Default Title","offer_id":49607479132298,"sku":"INF-S85-H-V4","price":5706.0,"currency_code":"NZD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0688\/4599\/4122\/files\/Infinity_V4_Header_7_c6cedb81-6d20-4849-847b-2bb843345876.jpg?v=1782660971","url":"https:\/\/qjipdu-tf.myshopify.com\/products\/bmw-s85-e60-m5-e63-m6-100-equal-length-headers","provider":"SBX Performance","version":"1.0","type":"link"}