{"product_id":"grimmspeed-bb550-turbocharger-2002-2007-wrx-2004-2021-sti","title":"Grimmspeed BB550+ Turbocharger 2002-2007 WRX \/ 2004-2021 STI","description":"\u003ch2 data-pm-slice=\"1 1 []\"\u003e\u003cspan\u003eBolt-On Fitment. Big Power.\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eMore horsepower. More top-end performance. No need to tear apart your engine bay. Meet the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eGrimmSpeed BB550+\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, engineered to deliver serious power with a true bolt-on design that works with your existing factory-style components.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-pm-slice=\"1 1 []\"\u003eBuilding on everything we learned from the BB500, we've combined proven engineering with our latest turbocharger technology to develop the BB550+ for next-generation STI performance.\u003cspan\u003e Featuring a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eceramic ball bearing system\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, the BB550+ delivers substantially greater horsepower at higher RPM while maintaining strong midrange performance.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAt its core is a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003ebillet 2618 aluminum compressor wheel\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e and an \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eInconel 713C turbine wheel\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, paired with carefully engineered housings designed for durability and high-flow performance. A larger \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e10cm turbine housing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e and \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e0.77 A\/R compressor housing\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e support the BB550+'s increased power potential, allowing it to continue building horsepower well into the upper RPM range.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-pm-slice=\"1 1 []\"\u003e\u003cspan\u003eWe've also completely redesigned the \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003ewastegate actuator\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, incorporating a billet aluminum body, dual-port design, and heavy-duty steel mounting bracket. Together, these improvements deliver smoother wastegate operation, tighter boost control, and greater flexibility when dialing in your setup.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAnd like the BB450+, the BB550+ is a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003etrue bolt-on turbocharger\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. It retains the factory mounting location and is designed to work with stock-style connections and existing compatible supporting components. \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eNo cutting, custom fabrication, or extensive modifications under the hood required.\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Just serious power without the complications of a custom turbo installation.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFor drivers ready to push their STI further, the BB550+ delivers significantly greater top-end performance while retaining much of the lower-RPM response of its predecessor.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eQuick Specs\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eBearing System:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Ceramic ball bearing\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eCompressor Wheel:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Billet 2618 aluminum\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eCompressor Wheel Inducer\/Exducer:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 57.53mm \/ 71.43mm\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eTurbine Wheel:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Inconel 713C\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eTurbine Wheel Inducer\/Exducer:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 55mm \/ 60mm\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan\u003e\u003cstrong\u003eCompressor Flow:\u003c\/strong\u003e 73 lbs\/min\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eCompressor Housing:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e A356 aluminum\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eCompressor Housing A\/R:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 0.77\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eTurbine Housing:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e HiSiMo\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eTurbine Housing Size:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 10cm\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eWastegate Actuator Material:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 6061 aluminum\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eWastegate Mounting Bracket:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Straight, 6-gauge zinc-plated steel\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eBoost Control Compatibility:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 3-port and 4-port configurations\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eWastegate Base Pressure:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 15 PSI (default)\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eAdjustable Base Pressure Range:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e 3–26 PSI with included spring combinations\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003cspan\u003eInstallation:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Factory-location bolt-on; no cutting or custom fabrication required\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eDyno Testing: Putting the BB550+ to Work\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eWe put the BB550+ to the test against the factory VF48 and our previous BB500 turbocharger to see how the larger design performs throughout the RPM range.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eTesting was conducted on a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eMustang Dyno\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e using a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e2020 Subaru STI\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e equipped with a built rod-and-piston engine, front-mount intercooler, 1300cc injectors, and E85 fuel.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan style=\"color: rgb(214, 31, 40);\"\u003eThe results speak for themselves.\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003ciframe title=\"VF48 vs BB500 vs BB550+\" aria-label=\"Line chart\" id=\"datawrapper-chart-w5Te8\" src=\"https:\/\/datawrapper.dwcdn.net\/w5Te8\/1\/\" style=\"width: 0; min-width: 100% !important; border: none;\" height=\"451\" data-external=\"1\"\u003e\u003c\/iframe\u003e\u003cscript type=\"text\/javascript\"\u003e(function(){function e(){window.addEventListener(`message`,function(e){if(e.data[`datawrapper-height`]!==void 0){var t=document.querySelectorAll(`iframe`);for(var n in e.data[`datawrapper-height`])for(var r=0,i;i=t[r];r++)if(i.contentWindow===e.source){var a=e.data[`datawrapper-height`][n]+`px`;i.style.height=a}}})}e()})();\u003c\/script\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eBB550+ Dyno Results:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-spread=\"false\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003ePeak Wheel Horsepower:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Approximately 530 WHP\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003ePeak Wheel Torque:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Approximately 465 lb-ft\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eHorsepower Gain vs. BB500:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Approximately +70 peak WHP\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eTorque Gain vs. BB500:\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Approximately +15 peak lb-ft\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003eThe real advantage becomes clear when examining the entire power curve.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eWhile the BB500 develops torque earlier, the BB550+ trades a modest amount of lower-RPM output for considerably greater top-end performance. The BB550+ overtakes the BB500 in horsepower at approximately \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e5,200 RPM\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, with the gap continuing to widen as engine speed increases.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAt approximately \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e6,500 RPM\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, the BB550+ maintains more than \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e520 WHP\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, compared to roughly \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e450 WHP\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e from the BB500. That's an advantage of more than \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e70 WHP at the same engine speed\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, demonstrating the BB550+'s ability to carry substantial power toward redline.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eAnd despite its larger design, the BB550+ still develops a noticeable torque bump around \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e4,500 RPM\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, helping preserve responsive midrange performance for a stock-location turbocharger.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eThere's even more potential beyond these results.\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e Our test vehicle's 1300cc injectors limited fuel delivery at approximately 530 WHP, so we capped the pull at \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e27 PSI of boost\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. Our engineering team estimates the BB550+ has another \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e5–6 PSI of boost\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e available before leaving its efficiency range, meaning the horsepower shown here doesn't necessarily represent the turbocharger's maximum capability. \u003c\/span\u003e\u003cspan\u003eThe result is a turbocharger that delivers considerably more high-RPM horsepower without an equally dramatic reduction in low-end performance, all while retaining the convenience of a factory-location, bolt-on design.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cspan\u003e*Dyno results reflect the specific test vehicle, supporting modifications, E85 fuel, and tuning. Individual results will vary.\u003c\/span\u003e\u003c\/em\u003e\u003c\/p\u003e\n\u003ch2 data-pm-slice=\"1 1 []\"\u003e\u003cspan\u003eHow The 550+ Stacks Up: More Power at Higher RPM\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003ciframe title=\"BB550+ vs BB500 vs BB450+\" aria-label=\"Line chart\" id=\"datawrapper-chart-mD1tq\" src=\"https:\/\/datawrapper.dwcdn.net\/mD1tq\/1\/\" style=\"width: 0; min-width: 100% !important; border: none;\" height=\"451\" data-external=\"1\"\u003e\u003c\/iframe\u003e\u003cscript type=\"text\/javascript\"\u003e(function(){function e(){window.addEventListener(`message`,function(e){if(e.data[`datawrapper-height`]!==void 0){var t=document.querySelectorAll(`iframe`);for(var n in e.data[`datawrapper-height`])for(var r=0,i;i=t[r];r++)if(i.contentWindow===e.source){var a=e.data[`datawrapper-height`][n]+`px`;i.style.height=a}}})}e()})();\u003c\/script\u003e\u003c\/p\u003e\n\u003cp data-pm-slice=\"1 1 []\"\u003e\u003cspan\u003eThe \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eBB550+ demonstrates its advantage as engine speed climbs\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, producing substantially greater horsepower than both the BB450+ and BB500 in the upper RPM range. While the smaller turbos develop torque earlier, the BB550+ continues building power, ultimately reaching approximately \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e530 WHP\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e and maintaining strong output toward redline.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFor STI drivers chasing \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003emaximum horsepower and sustained high-RPM performance\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, the BB550+ delivers a distinct advantage.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2 data-pm-slice=\"1 1 []\"\u003e\u003cspan\u003eRedesigned Wastegate Actuator: Precision Boost Control\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan\u003eThe BB550+ features our newly engineered \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003ebillet aluminum, dual-port wastegate actuator\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, designed for smoother operation, more consistent boost pressure, and precise control throughout the RPM range.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eWe also developed a heavy-duty mounting system using a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003estraight, 6-gauge zinc-plated steel bracket\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. Unlike thinner, bent brackets that can flex under load, this rigid design keeps the actuator rod properly aligned with the wastegate arm, reducing the potential for binding, inconsistent boost pressure, and long-term bracket fatigue.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFor greater tuning flexibility, each BB550+ ships with a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e15 PSI base spring\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e and an \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eadditional spring pack\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, allowing you or your tuner to adjust base pressure from \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e3–26 PSI\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e using different spring combinations. An included spring selection guide makes choosing the proper configuration straightforward.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe actuator's \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003edual-port design supports both traditional 3-port and advanced 4-port boost control configurations\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e. With a compatible 4-port setup, pressure can be applied to both sides of the internal diaphragm for finer control and greater flexibility at higher RPM.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eFitments\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul data-spread=\"false\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003e2004–2021 Subaru STI \u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003e\u003cspan\u003e2002-2007 Subaru WRX\u003c\/span\u003e\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eInstallation Note:\u003c\/strong\u003e The BB550+ is designed for direct bolt-on installation without cutting or custom fabrication. Proper ECU tuning is required to ensure safe operation and optimal performance. Additional supporting modifications may be necessary depending on your vehicle's setup and performance goals.\u003c\/em\u003e\u003c\/p\u003e\n\u003ch2 style=\"text-align: center;\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0743\/3165\/2402\/files\/BB450_and_BB550_Plus_Wastegate_Spring_Chart_1.pdf?v=1793653725\"\u003e\u003cem\u003eBB450+ \u0026amp; BB550+ WASTEGATE SPRING CHART\u003c\/em\u003e\u003c\/a\u003e\u003c\/h2\u003e\n\u003ch2 style=\"text-align: center;\"\u003e\u003cem\u003eINSTALL GUIDE\u003c\/em\u003e\u003c\/h2\u003e","brand":"Grimmspeed","offers":[{"title":"Default Title","offer_id":50835940343983,"sku":"GRM.1203.1.0","price":1999.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/3598\/4815\/files\/GRM.1203.1.0-BB550_Turbo-1.jpg?v=1793979493","url":"https:\/\/subimods.com\/products\/grimmspeed-bb550-turbocharger-2002-2007-wrx-2004-2021-sti","provider":"Subimods.com","version":"1.0","type":"link"}