The BL-5757 and BL-5858 are a budget entry level type turbo. These are based off the Garrett T04E/T31 frame (like the very popular Garrett 57-Trim turbocharger). The BL-5757 is a cast wheel unit with a power rating of about 500-550hp. The BL-5858 has a billet compressor wheel and an upgraded high-flow turbine wheel with a rating of 600-630hp. These units are Journal Bearing only and use T3 housings.