BMW F90 M5 S63 Spool Stage 3 Low Pressure Fuel Pump DIY Kit

The Spool Stage 3 low pressure fuel pump DIY kit for the BMW F90 M5 adds a second, boost-activated pump to roughly double the stock low side flow.

Why you need it

Upgraded high pressure pumps can now support much more direct injection fueling, which makes the stock in-tank pumps the limit on a high-power S63, especially on E85. This kit adds a secondary pump that comes in under boost, doubling flow capacity for more than 1200 whp of low pressure fueling regardless of fuel type, at a lower cost than a pre-assembled kit.

Fits

• BMW F90 M5 (S63)

What's included

• Secondary fuel pump assembly
• Secondary pump activation harness (option selected at checkout)
• Boost-activated switch
• Boost reference adapter
• Hardware pack
• Detailed assembly instructions

Good to know

Pick the activation harness that matches your setup: ground activation for a Reflex flying lead, ground plus power for a Reflex plug-and-play or Rev2 BM3 setup, or the Spool Hobbs switch harness for boost-pressure activation without a controller. A supporting tune is required to make use of the added fueling. Professional installation is recommended.