Turbocharger BMW X3 X5 X6 335 435 535 640 740 8508091 New Turbo Small Side 8508091 – Small Side. This engine comes with a variety of turbo options. It is important to ensure that the part numbers on your current turbo match those specified in our advertisement. This Turbo has top quality Billet compressor wheel manufactured from solid (MFS) billet alloy via precision 5 axis CNC machine. It is the same size as the standard wheel but it is stronger and lighter which allows the turbo to spool up a little bit faster.