{"product_id":"grimmspeed-bb550-turbocharger","title":"GrimmSpeed BB550+ Turbocharger","description":"\u003cp\u003e\u003cstrong\u003eBolt-On Fitment. Big Power.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eMore horsepower. More top-end performance. No need to tear apart your engine bay. Meet the GrimmSpeed BB550+, engineered to deliver serious power with a true bolt-on design that works with your existing factory-style components.\u003c\/p\u003e\n\u003cp\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. Featuring a ceramic ball bearing system, the BB550+ delivers substantially greater horsepower at higher RPM while maintaining strong midrange performance.\u003c\/p\u003e\n\u003cp\u003eAt its core is a billet 2618 aluminum compressor wheel and an Inconel 713C turbine wheel, paired with carefully engineered housings designed for durability and high-flow performance. A larger 10cm turbine housing and 0.77 A\/R compressor housing support the BB550+'s increased power potential, allowing it to continue building horsepower well into the upper RPM range.\u003c\/p\u003e\n\u003cp\u003eWe've also completely redesigned the wastegate actuator, 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\/p\u003e\n\u003cp\u003eAnd like the BB450+, the BB550+ is a true bolt-on turbocharger. It retains the factory mounting location and is designed to work with stock-style connections and existing compatible supporting components. No cutting, custom fabrication, or extensive modifications under the hood required. Just serious power without the complications of a custom turbo installation.\u003c\/p\u003e\n\u003cp\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\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDyno Testing: Putting the BB550+ to Work\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\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\/p\u003e\n\u003cp\u003eTesting was conducted on a Mustang Dyno using a 2020 Subaru STI equipped with a built rod-and-piston engine, front-mount intercooler, 1300cc injectors, and E85 fuel.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe results speak for themselves.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBB550+ Dyno Results:\u003c\/p\u003e\n\u003cp\u003ePeak Wheel Horsepower: Approximately 530 WHP\u003c\/p\u003e\n\u003cp\u003ePeak Wheel Torque: Approximately 465 lb-ft\u003c\/p\u003e\n\u003cp\u003eHorsepower Gain vs. BB500: Approximately +70 peak WHP\u003c\/p\u003e\n\u003cp\u003eTorque Gain vs. BB500: Approximately +15 peak lb-ft\u003c\/p\u003e\n\u003cp\u003eThe real advantage becomes clear when examining the entire power curve.\u003c\/p\u003e\n\u003cp\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 5,200 RPM, with the gap continuing to widen as engine speed increases.\u003c\/p\u003e\n\u003cp\u003eAt approximately 6,500 RPM, the BB550+ maintains more than 520 WHP, compared to roughly 450 WHP from the BB500. That's an advantage of more than 70 WHP at the same engine speed, demonstrating the BB550+'s ability to carry substantial power toward redline.\u003c\/p\u003e\n\u003cp\u003eAnd despite its larger design, the BB550+ still develops a noticeable torque bump around 4,500 RPM, helping preserve responsive midrange performance for a stock-location turbocharger.\u003c\/p\u003e\n\u003cp\u003eThere's even more potential beyond these results. Our test vehicle's 1300cc injectors limited fuel delivery at approximately 530 WHP, so we capped the pull at 27 PSI of boost. Our engineering team estimates the BB550+ has another 5–6 PSI of boost available before leaving its efficiency range, meaning the horsepower shown here doesn't necessarily represent the turbocharger's maximum capability. The 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\/p\u003e\n\u003cp\u003e*Dyno results reflect the specific test vehicle, supporting modifications, E85 fuel, and tuning. Individual results will vary.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRedesigned Wastegate Actuator: Precision Boost Control\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe BB550+ features our newly engineered billet aluminum, dual-port wastegate actuator, designed for smoother operation, more consistent boost pressure, and precise control throughout the RPM range.\u003c\/p\u003e\n\u003cp\u003eWe also developed a heavy-duty mounting system using a straight, 6-gauge zinc-plated steel bracket. 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\/p\u003e\n\u003cp\u003eFor greater tuning flexibility, each BB550+ ships with a 15 PSI base spring and an additional spring pack, allowing you or your tuner to adjust base pressure from 3–26 PSI using different spring combinations. An included spring selection guide makes choosing the proper configuration straightforward.\u003c\/p\u003e\n\u003cp\u003eThe actuator's dual-port design supports both traditional 3-port and advanced 4-port boost control configurations. 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\/p\u003e","brand":"Grimmspeed","offers":[{"title":"Default Title","offer_id":58789914738991,"sku":"GRM.1203.1.0","price":3749.95,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0848\/3903\/9279\/files\/GRM.1203.1.0-BB550_Turbo-1.jpg?v=1793925805","url":"https:\/\/www.prospeedracing.com.au\/products\/grimmspeed-bb550-turbocharger","provider":"Pro Speed Racing","version":"1.0","type":"link"}