This kit adds a second CP3 to USA spec 09-11 335D's. The second pump used can be either a BMW R70 or R90. 

The dual cp3 kit includes the bracket, Fish Tuning dual cp3 controller, pulley hubs & pulleys, cogged belt, fuel lines, fuel fittings, clamps, pump hub counterhold wrench, and all necessary hardware. All machined parts are made 100% in-house!

Available as a kit only or with a brand new Bosch pump with a 2 year unlimited mileage warranty. A 2700Bar genuine BMW rail pressure sensor is also available to add to each option. 

The stock M57 in tank lift pump has been tested to maintain supply pressure up to approximately 400whp with the dual cp3 kit. An add on upgraded lift pump kit is available as an option. The 100% plug and play in tank lift pump kit is all brand new parts custom assembled by Precision Raceworks using a Walbro 535 fuel pump. It is a bucketed system that is a direct factory replacement part. The top hat from your oem sending unit is the only part that needs to be transferred over. The Walbro 535 draws 18.X amps per test bench measurements. The OEM BMW EKP is rated and fused for 20 amps. Some cars have thrown an overcurrent fault in the EKP but it does not set a check engine light. Our personal test car has logged over 25k miles with the OEM EKP and the Walbro 535 without throwing a fault.

Those looking for an upgraded EKP solution, these are the two options we know of https://speedsty.com/products/ekpm-replacement-board?variant=44445909909814 and https://www.eospeed.com/products/bpm4-low-pressure-fuel-pump-controller . We have not have a chance to test either personally yet. 

Instructions for the kit can be found here.