Velocity Stacks, Billet, Suzuki Hayabusa

These aluminum stacks are machined from solid billet and feature an elliptical flare to 79.5mm dia. to provide to optimum capture coefficient in addition to properly matching the 50mm ID of the throttle body. The result is improved flow capability. Molded neoprene seals are included which fit the Hayabusa airbox exactly.

Three lengths of velocity stacks are offered; 41mm (same length as stock Hayabusa short rubber stacks), 60mm and 72mm (approx. the same length as stock Hayabusa long rubber stacks). The long stack are offered as a set paired with a set of short stacks to match the stock Hayabusa setup but offer improved flow capability and torque (HAY1017-STREET). In addition, a tuner’s set is offered which includes 4 x 41mm stacks, 4x 60mm stacks and 2 x 72mm stacks, and one set of seals.

The optimum set up for your bike depends on the modification of the bike and your objectives. Some general guidelines are:

41mm stacks- Best used on highly modified engines long duration cams with 4:1 exhaust, where horsepower at high rpm is desired.

2 x 41mm + 2 x 72mm street stacks- Best used on relatively stock bikes where the stock torque band is retained but improved.

60mm stacks- A compromise between the former two combinations. Works well with stock bikes and modified bikes. It will provide improved hp in the mid to upper rpm band.

To read more information, check out this tech article.

Installation instructions:

(Reference the Suzuki Service Manual for more details about the filter box removal.)

1. Remove the air filter box from the bike:
   1. Lift tanks and support with stay.
   2. Disconnect the IAT and IAP sensors couplers
   3. Disconnect the vacuum hose at the lower rear of the box.
   4. Disconnect the crankcase breather hose at the top rear of the box and the large pair hose at the lower right rear corner of the box.
   5. Loosen the throttle body clamp screws on the air box side (one on each side). It may be necessary to first remove the throttle cables to gain access to the screw on the throttle cable side.
   6. Remove the top forward air box mounting screw.
   7. Disconnect the vacuum hose that goes to the lower center mounted air damper control actuator.
   8. Remove air box.
2. Remove the stock velocity stacks.
3. Install the new velocity stack seals (without the velocity stacks) in the air box.
4. Rotate the seals so the eccentric is located in the same direction as the stock eccentric.
5. Before installing the new velocity stacks in the seals, check that the pilot flange fits over the mouth of the throttle body. (Since this part of the throttle body is not machined, it is possible that the flashing at the casting parting line may project enough to cause a problem. If so, carefully remove the edge with a file.)
6. Lubricate the inside surface of the seal with Silicon spray lubricant. This is important; otherwise it will be difficult to install the velocity stacks. Oil or grease also works, but messy.
7. Install the new aluminum velocity stacks down into the seals until the forward ring snaps into the groove in the seal. It will take some force but it will go. Avoid using metal tools, they should not be needed.

(Removing the velocity stacks also takes some finesse. From the bottom of the air box, pull the thin section of the rubber gasket up and away from the stack while wobbling the stack from the inside of the box. Once the lip is out of the gasket groove, the stack can be worked up and out.)

8. Install the stock throttle body clamps on the new seals with the same orientation as on the stock units. Silicon spray lubrication on the seals will ease assembly on the throttle bodies, but is not necessary.
9. Install the air box and wiggle or gently rotate the alloy velocity stacks to feel that the pilot flange is seated over the throttle body and is centered. Tighten the clamps.
10. Reconnect sensors, hoses, cables and mounting screw in reverse order to as listed above.

 41mm Short Stacks Polished

 Tuners Kit (4-41mm, 4-60mm, 2-72mm)

Related Items:
Ram Air Seals
Ram Air Scoops
Air Filter
Timing Retard Eliminator
Power Commander

Other Options:
Factory Pro Velocity Stacks
Suzuki OEM Short Stacks