Spool - Helix HPFP Overdrive Unit

Note: All new Helix purchases include our billet vacuum cover mounting plate, support bracket, and necessary hardware for installation. No separate purchase necessary. Spool Performance Helix HPFP overdrive system Spool Performance is really excited to introduce our latest product offering to the N54/early N55 community, the Helix overdrive unit. We have been testing this for almost a year now and here it is finally!! What is the Helix? The Helix is simply put, a planetary gearbox for your High-pressure fuel pump. It is very similar to what you would find in your automatic transmission. A planetary gearbox allows you to change gear ratios in an axial configuration. It consists of three types of gears- ring gear, planet gears, and a sun gear. In our configuration, the planet gears and the sun gears are on different rotating axles and the ring gear is stationary.  The particular configuration of the gears and their spatial fixturing allows an axial increase in shaft speed from the input