VF Engineering BMW 5 Series 525 Supercharger Kit 2001-2004 vs VF Engineering Supercharger System - 2004-2006 BMW 3-Series (325)

Both are VF Engineering centrifugal Vortech kits tuned to about 6 psi, so the real choice is which car you own, not which kit is better. The 5 Series kit is the more thoroughly documented of the two, with published output figures of 480 hp and 380 lb-ft, a self-contained V3 Si-Trim blower, a water-cooled design and a Bosch boost overrun system. The 3 Series kit is the older, simpler E46 system, and VF is candid that its main software work went into fixing the stalling and MAF faults other kits had. Owners of both praise smooth, stock-like drivability and criticize the install time and the need for supporting mods.

• Choose the VF 5 Series 525 kit if you have a 2001-2004 E39 525i and want the kit with published power figures, water cooling and a self-contained blower.
• Choose the VF 3 Series 325 kit if you have a 2004-2006 E46 325i and want VF's proven ECU fix for the stalling and MAF problems that plague rival kits.