EFR6258 Turbocharger

The BorgWarner EFR6258 turbocharger represents a high-performance upgrade, incorporating cutting-edge technology for motorsports enthusiasts. It is highlighted as a top-tier option, particularly noted for its suitability for applications like the Mazda MX-5, leveraging the engineering expertise of BorgWarner's motorsports division. At its core, the EFR6258 features a 62mm exducer and 49.6mm inducer compressor wheel, utilizing a Forged-Milled Wheel (FMW) Extended Tip design. This setup achieves a maximum flow rate of 44 lb/min, with a potential to support up to 440bhp. The turbocharger is equipped with dual-row ceramic ball bearings, which minimize friction and promote rapid spool and response, while also offering extreme durability. The center housing is water-cooled, with a recommendation for using 14mm banjo bolts, and double seals on both the turbine and compressor ends enhance its resistance to oil seepage and overall longevity. Additional technical highlights include a low-inertia Gamma-Ti turbine wheel measuring 58mm OD, housed within a stainless steel investment cast housing. Options for AR ratios include 0.64 for a T25 housing (Internal WG) and 0.80 for a T4 Twin Scroll housing (Internal WG). The compressor housing features a 2.5″ inlet and a 2.0″ hose coupler outlet, with an integrated blow-off valve (BOV) designed to improve response during throttle transitions. It is also equipped with provisions for an integrated speed sensor and is capable of handling a 3.6 pressure ratio, equating to approximately 37 PSI of boost. BorgWarner's design emphasizes efficiency and performance, with tuning notes suggesting potential for 410-430 BHP at 26-27 PSI on optimized setups requiring an oversized intercooler and camshafts capable of reaching ~7400 RPM. On pump fuel with a 10:1 compression engine, it can produce around 340-350bhp at 18 PSI, operating within the turbo's efficiency band.