Graves Motorsports Yamaha R1 Lower 50mm Velocity Stacks for the 2009-2013 models. These 50MM Lower Velocity Stacks with Pivots were developed by Graves Motorsports for your Cross Plane Crank R1. This item is the "Lower" stack assembly only (see item # ABY-09R1-REVT to purchase the top add-on).
This stack kit improves power throughout the entire RPM range. The staggered tops allow the cylinders to share the available volume of air in the R1ís air-box evenly at low and mid range RPMs.
The shorter than stock lower stacks feed the R1ís appetite for big air when the upper stacks raise improving top end power.
These stacks developed on the Graves Yamaha Superbike give our riders the drivability needed to win races. Available now for your 2009-2013 Yamaha R1.
You can purchase the complete kit by ordering this item along with Part # ABY-09R1-REVB (sold seperately) or just this lower piece only for use with the stock uppers.
NOTE: Uppers cannot be used with the stock lower velocity stacks.
Author: jerry daggett team zyvax r1
The new velocity stack set-up has proven
to be a great tuning asset in the development of the Team Zyvax R1
endurance bike.This item does a lot to
enhance the strong benifits of the cross-
plane engine design.
Author: Bryan Niles
The Stacks top and bottom are fantastic are a fantastic combnaton. The bike pulls harder and faster than before. Wants to keep pulling even at redline. No brainer Significantly more power from bottom to redline. This is the way the bike shuld have come from the factory.
Author: Brian Evans
These bottom velocity stacks are no nice it really highlights how inexpensively made the oem velocity stacks are. Nice packaging, fit and finish - Graves makes top quality kit! Could use some directions but I did find info in the R1 Kit Parts manual available here -> http://www.yamaha-racingparts.com/downloads/manuals/2010_R1_Kit_Manual_English.pdf starting on page 13. FYI...The picture above differs from the kit manual - the support arms, as pictured above, are switched for the levers used on the upper velocity stacks. You can see the difference after reviewing the above link. Honestly, the Graves supplied parts could not be nicer and worth every penny.