{"product_id":"spectre-coupler-reducer-4in-to-3-5in-pvc-black","title":"Spectre Coupler\/Reducer 4in. to 3.5in. (PVC) - Black","description":"\u003cp\u003eThe Spectre Coupler\/Reducer 4in. to 3.5in. (PVC) in Black (part number 9741) is a step-down connector that transitions between a 4-inch and a 3.5-inch intake tube, air box outlet, or ducting component in naturally aspirated applications. The 9741 eliminates the need to fabricate a custom adapter or source a hard-to-find OEM reducer, making it a practical solution for cold-air intake builds, air box modifications, and replacement of cracked or deteriorated factory couplers. Included stainless steel worm-gear clamps ensure a leak-free, rattle-resistant connection at both ends. Not for use on pressurized (turbocharged or supercharged) systems.\u003c\/p\u003e\n\n\u003ch4\u003eFeatures and Benefits\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eTransitions from 4-inch to 3.5-inch diameter for intake tube diameter changes\u003c\/li\u003e\n\u003cli\u003ePVC construction is flexible, vibration-resistant, and easy to install in tight spaces\u003c\/li\u003e\n\u003cli\u003eBlack finish integrates cleanly with aftermarket cold-air intake systems\u003c\/li\u003e\n\u003cli\u003eIncludes stainless steel worm-gear hose clamps for both ends\u003c\/li\u003e\n\u003cli\u003eEliminates the need for custom fabrication when connecting mismatched tube diameters\u003c\/li\u003e\n\u003cli\u003eCompatible with aluminum, steel, ABS, and plastic intake tubing at the specified diameters\u003c\/li\u003e\n\u003cli\u003eDurable PVC material resists cracking from heat cycling in under-hood environments\u003c\/li\u003e\n\u003cli\u003eSpectre Performance quality ensures consistent wall thickness and dimensional accuracy\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eSpecifications\u003c\/h4\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003e9741\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eSpectre Performance\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003ePVC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLarge End ID\u003c\/td\u003e\n\u003ctd\u003e4 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSmall End ID\u003c\/td\u003e\n\u003ctd\u003e3.5 inches\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eColor\u003c\/td\u003e\n\u003ctd\u003eBlack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoupler Style\u003c\/td\u003e\n\u003ctd\u003eReducer (step-down)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHardware Included\u003c\/td\u003e\n\u003ctd\u003eStainless steel worm-gear hose clamps\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eNaturally aspirated intake \/ ducting only (non-pressurized)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003eSpectre Performance limited warranty\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch4\u003eWhat's Included\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e1 x Spectre 9741 PVC reducer coupler (4in to 3.5in ID, black)\u003c\/li\u003e\n\u003cli\u003e2 x Stainless steel worm-gear hose clamps (one per end)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eFrequently Asked Questions\u003c\/h4\u003e\n\u003cp\u003e\u003cstrong\u003eWhat tube sizes does the Spectre 9741 connect?\u003c\/strong\u003e\u003cbr\u003e\nThe 9741 has a 4-inch ID on the large end and a 3.5-inch ID on the small end, designed to transition between these two common intake tube diameters.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCan the Spectre 9741 be used on a forced-induction vehicle?\u003c\/strong\u003e\u003cbr\u003e\nNo. The 9741 is a PVC coupler rated for naturally aspirated applications only. It is not designed for pressurized intake systems. Use a silicone reducer rated for boost pressure on turbocharged or supercharged vehicles.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDoes the 9741 come with hose clamps?\u003c\/strong\u003e\u003cbr\u003e\nYes. The Spectre 9741 includes two stainless steel worm-gear hose clamps, one for the 4-inch end and one for the 3.5-inch end.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat is the length of the Spectre 9741?\u003c\/strong\u003e\u003cbr\u003e\nSpectre describes the 9741 as approximately 3 inches in length. Confirm dimensions for your specific fitment requirements before ordering.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWill the 9741 work with an aluminum intake tube?\u003c\/strong\u003e\u003cbr\u003e\nYes. PVC couplers are compatible with aluminum, mild steel, ABS plastic, and similar tube materials. The worm-gear clamps grip the tube OD regardless of material.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eIs the 9741 reversible (can the 3.5in side face upstream)?\u003c\/strong\u003e\u003cbr\u003e\nPhysically yes, but for proper airflow management the reducer should be oriented with the larger end toward the air source and the smaller end toward the engine, unless your specific intake design requires otherwise.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eHow do I prevent the Spectre 9741 from leaking at the joints?\u003c\/strong\u003e\u003cbr\u003e\nEnsure both tube ends are inserted fully into the coupler ends before tightening the clamps. Position each clamp over the coupler-tube overlap zone and tighten evenly to 30-35 in-lb. Avoid over-tightening, which can distort the PVC.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCan I use the 9741 to connect an aftermarket air filter to a stock airbox outlet?\u003c\/strong\u003e\u003cbr\u003e\nYes, if the airbox outlet measures 4 inches OD and the filter inlet measures 3.5 inches OD (or vice versa). Confirm the OD dimensions of both components match the ID of the corresponding coupler end before installation.\u003c\/p\u003e\n\n\u003ch4\u003eInstallation Instructions\u003c\/h4\u003e\n\u003col\u003e\n\u003cli\u003eConfirm the tube OD dimensions at both connection points match the 4in and 3.5in ends of the 9741.\u003c\/li\u003e\n\u003cli\u003eSlide a hose clamp over each tube end before inserting into the coupler.\u003c\/li\u003e\n\u003cli\u003eInsert the 4-inch tube fully into the large end of the Spectre 9741.\u003c\/li\u003e\n\u003cli\u003eInsert the 3.5-inch tube fully into the small end of the coupler.\u003c\/li\u003e\n\u003cli\u003ePosition each hose clamp over the coupler-to-tube overlap zone on each side.\u003c\/li\u003e\n\u003cli\u003eTighten both clamps evenly until snug, without over-compressing the PVC walls.\u003c\/li\u003e\n\u003cli\u003eInspect both joints for gaps and verify the assembly is seated straight before starting the engine.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003e\u003cstrong\u003eProposition 65 Warning:\u003c\/strong\u003e This product can expose you to chemicals including Diisononyl Phthalate (DINP), which is known to the State of California to cause cancer. For more information, go to \u003ca href=\"https:\/\/www.p65warnings.ca.gov\"\u003ewww.P65Warnings.ca.gov\u003c\/a\u003e.\u003c\/p\u003e","brand":"Spectre","offers":[{"title":"Default Title","offer_id":40482907488335,"sku":"SPE9741","price":19.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1062\/7920\/files\/spectre-couplerreducer-4in_-to-3_5in_-pvc-black-silicone-couplers-hoses-spectre.jpg?v=1699980124","url":"https:\/\/www.blackopsautoworks.com\/products\/spectre-coupler-reducer-4in-to-3-5in-pvc-black","provider":"Black Ops Auto Works","version":"1.0","type":"link"}