{"product_id":"tr-gtx2971-twin-scroll-stock-replacement-for-subaru-wrx-02-07-and-sti-04-18","title":"TR GTX2971 Twin Scroll Stock Replacement for Subaru WRX 02-07 and STi 04-18","description":"\u003cp\u003eIntroducing the twin scroll GTX2971 for Subaru 02-07 WRX and 04-18 STi! Just like the GTX2971R,this twin scroll edition features a ball-bearing cartridge, billet compressor wheel , and 10\u003cspan\u003ecm\u003c\/span\u003e\u003csup\u003e2\u003c\/sup\u003e housing. Thanks to the billet compressor wheel the overall weight of the wheel is lighter than competing turbochargers and allows for maximum airflow throughout the unit with the help of point milling on each blade. A unique wheel and blade design, featuring a 20% larger wheel with 17% longer blades than the factory turbocharger. In addition, the GTX2971 features a port and polished exhaust housing to minimize exhaust flow turbulence. All hardware is included with purchase.\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003eThis is the ultimate replacement for Twinscroll VF36 VF37 and VF38 \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eTR\u003c\/b\u003e has partnered with \u003cb\u003eMotul USA\u003c\/b\u003e to offer a free 2L can of 300V 5W30 or 5W40 with any purchase of TR turbos! Choose your oil of choice in the options and we will include it in your order!\u003cspan class=\"Apple-converted-space\"\u003e \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003eDo you need more Motul 300v? Add some more \u003ca href=\"https:\/\/www.tomiokaracing.com\/collections\/motul-300v\"\u003e\u003cspan\u003e\u003cb\u003eHERE\u003c\/b\u003e\u003c\/span\u003e\u003c\/a\u003e!\u003cspan class=\"Apple-converted-space\"\u003e \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNOTE\u003c\/strong\u003e: This turbocharger requires the usage of twin scroll headers and downpipe.\u003c\/p\u003e\n\u003ctable width=\"603\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd bgcolor=\"#CCCCCC\"\u003e\n\u003cp\u003e\u003cstrong\u003eBearing Type:\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd bgcolor=\"#CCCCCC\"\u003e\n\u003cp\u003eBall-Bearing\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eFlange Type:\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cp\u003eStandard Subaru 5-Bolts\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd bgcolor=\"#CCCCCC\" rowspan=\"2\"\u003e\u003cstrong\u003eCompressor Wheel:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd bgcolor=\"#CCCCCC\"\u003eIn: 54 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd bgcolor=\"#CCCCCC\"\u003eEx: 72 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd height=\"27\" rowspan=\"2\"\u003e\n\u003cp\u003e\u003cstrong\u003eTurbine Wheel:\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd\u003eIn: 60 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEx: 57 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd bgcolor=\"#CCCCCC\"\u003e\n\u003cp\u003e\u003cstrong\u003eTurbine Housing:\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd bgcolor=\"#CCCCCC\"\u003e\n\u003cp\u003e10cm\u003csup\u003e2\u003c\/sup\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp\u003e\u003cstrong\u003eActuator:\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd\u003e\n\u003cp\u003e1.1 bar \/ 16 psi\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd bgcolor=\"#CCCCCC\"\u003e\n\u003cp\u003e\u003cstrong\u003eHorsepower:\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003ctd bgcolor=\"#CCCCCC\"\u003e\n\u003cp\u003e550 HP\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ctable style=\"width: 99.915%; height: 469.454px;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"height: 39.2045px;\"\u003e\n\u003cth style=\"width: 26.9684%; height: 39.2045px;\"\u003eFeature\u003c\/th\u003e\n\u003cth style=\"width: 32.992%; height: 39.2045px;\"\u003eTR-TS1047 Twin Scroll GTX2971\u003c\/th\u003e\n\u003cth style=\"width: 36.4684%; height: 39.2045px;\"\u003eTR-TS1027 Tomioka Racing TD06-20G Billet\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr style=\"height: 39.2045px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 39.2045px;\"\u003eCompatibility\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 39.2045px;\"\u003e2002-2007 WRX, 2004-2018 STi\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 39.2045px;\"\u003e2002-2007 WRX, 2004-2020 STI\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 19.6023px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 19.6023px;\"\u003eBearing Type\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 19.6023px;\"\u003eBall-Bearing\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 19.6023px;\"\u003eJournal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 39.2045px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 39.2045px;\"\u003eCompressor Wheel Material\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 39.2045px;\"\u003eBillet\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 39.2045px;\"\u003eBillet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 39.2045px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 39.2045px;\"\u003eCompressor Wheel Size (mm)\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 39.2045px;\"\u003eIn: 54, Ex: 72\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 39.2045px;\"\u003eIn: 52, Ex: 68\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 39.2045px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 39.2045px;\"\u003eTurbine Wheel Size (mm)\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 39.2045px;\"\u003eIn: 60, Ex: 57\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 39.2045px;\"\u003eIn: 61, Ex: 54\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 19.6023px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 19.6023px;\"\u003eTurbine Housing Size\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 19.6023px;\"\u003e10cm2\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 19.6023px;\"\u003e8cm2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 39.2045px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 39.2045px;\"\u003eWeight of Compressor Wheel\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 39.2045px;\"\u003eLighter than competing turbos\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 39.2045px;\"\u003e10% improvement over standard wheel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 39.2045px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 39.2045px;\"\u003eWheel and Blade Design\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 39.2045px;\"\u003e20% larger wheel, 17% longer blades\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 39.2045px;\"\u003eNot specified\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 39.2045px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 39.2045px;\"\u003eExhaust Housing\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 39.2045px;\"\u003ePort and polished to minimize turbulence\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 39.2045px;\"\u003eNot specified\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 39.2045px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 39.2045px;\"\u003eMaximum Horsepower Support\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 39.2045px;\"\u003e550 HP\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 39.2045px;\"\u003e530 HP\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 38.2045px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 38.2045px;\"\u003eSpool Characteristics\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 38.2045px;\"\u003eTwin-scroll design for optimal spooling\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 38.2045px;\"\u003eFast spool, ideal for maintaining high HP\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"height: 39.2045px;\"\u003e\n\u003ctd style=\"width: 26.9684%; height: 39.2045px;\"\u003eInstallation\u003c\/td\u003e\n\u003ctd style=\"width: 32.992%; height: 39.2045px;\"\u003eRequires twin-scroll headers and downpipe\u003c\/td\u003e\n\u003ctd style=\"width: 36.4684%; height: 39.2045px;\"\u003e100% bolt-on\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"text-decoration: underline;\"\u003e\u003cstrong\u003eApplications:\u003c\/strong\u003e\u003c\/span\u003e\u003cbr\u003e2002 - 2007 Subaru WRX\u003cbr\u003e2004 - 2018 Subaru STi\u003cbr\u003e\u003c\/p\u003e\n\u003cul\u003e\u003c\/ul\u003e\n\u003cp\u003e\u003cspan style=\"text-decoration: underline;\"\u003e\u003cstrong\u003eKit Contents:\u003c\/strong\u003e\u003c\/span\u003e\u003cbr\u003eTurbocharger\u003cbr\u003eGaskets\u003cbr\u003eHardware Kit\u003cbr\u003eActuator\u003cbr\u003eOil Pipe\u003cbr\u003eWater Pipe\u003cbr\u003eMotul 300V 2L\u003cbr\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWastegate actuator spring choice: 1.1 bar vs 1.3 bar (what customers need to know)\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eWhat the spring actually controls (and why it matters)\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOn a pneumatic internal wastegate, the actuator spring sets your gate pressure (often called base boost): the boost level where the wastegate starts to open because boost pressure overcomes spring force. Haltech describes it simply: changing spring pressure changes the default boost pressure, and when boost exceeds spring pressure the valve opens and begins regulating boost.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eChoose 1.1 bar (16.1 psi) \/ Red if:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYou want a lower boost map (street\/traction\/valet) around the mid-teens. Remember: you can’t go under the spring.\u003c\/p\u003e\n\u003cp\u003eYour normal target boost is roughly 18–22 psi and you want good controller authority and flexibility.\u003c\/p\u003e\n\u003cp\u003eYou’re building a setup where drivability and multiple boost modes matter (daily + weekend map).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eChoose 1.3 bar (19.1 psi) \/ Silver if:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYou will not run low boost—your “low boost” is still ~19 psi or higher. (If you need 15–17 psi sometimes, don’t pick this.)\u003c\/p\u003e\n\u003cp\u003eYour normal target boost is roughly 22–28 psi and you want:\u003c\/p\u003e\n\u003cp\u003eless “work” from the boost control system to hit target, and\u003c\/p\u003e\n\u003cp\u003etypically better resistance to the wastegate being pushed open early (especially in higher load \/ backpressure situations).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThere are two different “maximum boost” questions people ask:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e1) Maximum boost your boost control can hold consistently\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eUsing the GFB rule-of-thumb (target boost ≤ ~2× gate pressure) :\u003c\/p\u003e\n\u003cp\u003eWith a 1.1 bar \/ 16.1 psi spring, the “control stability ceiling” is roughly ~32 psi (2 × 16.1).\u003c\/p\u003e\n\u003cp\u003eWith a 1.3 bar \/ 19.1 psi spring, the “control stability ceiling” is roughly ~38 psi (2 × 19.1).\u003c\/p\u003e\n\u003cp\u003eReality check: that does not mean “safe to run 32–38 psi.” It means beyond ~2× gate pressure, boost control tends to get inconsistent because the actuator isn’t receiving enough meaningful reference signal for correction. GFB explains that once you go beyond double, boost control becomes less stable and more affected by variables like RPM\/load\/backpressure.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e2) Maximum boost your turbo\/engine can safely run\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThat’s not spring-limited. It’s limited by:\u003c\/p\u003e\n\u003cp\u003eturbo efficiency and speed\/heat,\u003c\/p\u003e\n\u003cp\u003efuel quality and knock margin,\u003c\/p\u003e\n\u003cp\u003eintake temps\/intercooling,\u003c\/p\u003e\n\u003cp\u003eexhaust backpressure,\u003c\/p\u003e\n\u003cp\u003eengine\/clutch\/trans limits,\u003c\/p\u003e\n\u003cp\u003etuner strategy.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFAQ:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan I run less boost than the spring rating?\u003c\/strong\u003e\u003cbr\u003eNo. Spring pressure is the lowest boost level you can reach.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDoes a stiffer spring automatically mean higher peak boost?\u003c\/strong\u003e\u003cbr\u003eNot automatically. It mainly raises minimum boost and changes how the wastegate behaves. Boost above spring comes from the control strategy.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy do people say “don’t exceed 2× the spring”?\u003c\/strong\u003e\u003cbr\u003eBecause boost control gets less stable as target boost gets too far above gate pressure; beyond ~double you tend to lose correction authority.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat spring gives the best spool and boost stability?\u003c\/strong\u003e\u003cbr\u003eA spring that puts gate pressure about 10–20% under your target boost is a strong general guideline for best performance.\u003cbr\u003e\u003c\/p\u003e","brand":"Tomioka Racing (TR)","offers":[{"title":"1.1 bar","offer_id":46718950015139,"sku":"TR-TS1047-1.1","price":1965.0,"currency_code":"USD","in_stock":true},{"title":"1.3 bar","offer_id":46718950047907,"sku":"TR-TS1047-1.3","price":1965.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0678\/3398\/7235\/files\/TR-TW1047_Web_Pic.jpg?v=1767649796","url":"https:\/\/wiscomotors.com\/products\/tr-gtx2971-twin-scroll-stock-replacement-for-subaru-wrx-02-07-and-sti-04-18","provider":"Wisco Motors","version":"1.0","type":"link"}