The Precision Raceworks BMW Boost Referenced Pump Activation Harness is the preferred method to control auxiliary fuel pumps by pump manufactures and tuners alike.
This kit is considered the most complete and highest quality kit on the market and is sold private label to many BMW pump manufactures. That is why this harness is the #1 method of secondary pump control on the market around the globe.
Each kit includes a boost referenced pressure switch often referred to as a "hobbs switch" however our pressure switch is designed for exposure to oil as well as air and is safe for engine bay temperatures for years of reliable service unlike a "hobbs switch" which is deigned for use in swimming pool and hot tub applications.