This installation kit provides the reservoir and plumbing components needed to set up a Holley water/methanol injection system on a Dominator or HP EFI system.
Specifications:
- Reservoir Size: 6" wide x 4" deep x 5" tall
- Compatible Systems: Holley Dominator and HP EFI
- Compatible Mix: Up to 50/50 water/methanol
- Includes: Reservoir, low-level float, 1/4" ID x 1/2" OD 6 ft. polyurethane tubing, 1/4" OD 16 ft. nylon tubing, filter, 3/8" NPT-1/4" ID tube fitting, relay, stainless 3/8" NPT-1/4" OD tube fitting, relay wiring and fuse, and warning LED
- Part Number: 557-101
The water/methanol solenoid is run by an injector driver output; if an extra output isn't available (such as on an HP ECU driving 8 injectors), Holley P/N 554-115 can be used with a low-side PWM output instead.
FAQ
What does the 557-101 installation kit include?
It includes the reservoir, low-level float, tubing, filter, fittings, relay with wiring and fuse, and a warning LED.
What systems is it compatible with?
It's designed for use with Holley Dominator and HP EFI systems.
What's the reservoir size?
The reservoir measures 6" wide by 4" deep by 5" tall.

