danST Engineering are pleased to offer this high quality velocity stack kit for the Kawasaki ZX12R throttle bodies. The kit consists of the following:

4x Flange fitment 50mm Diameter Spun Aluminium trumpets 25/50/90mm Lengths

4x Clamp Rings with Inside Diameter 56.5mm and Outside Diameter of 75mm with grub screws

4 x Machined Aluminium Adapter Spigots with grub screws 

8x M6 Button Head Screws

A dimensional drawing of the available trumpet sizes can be seen here: Velocity Stack Dimension Drawing

This kit has been designed for anyone running the bike throttle bodies without the original airbox arrangement - particularly in kit or modified car applications.

A pipercross PX500 or PX600 with the appropriate baseplate can be incorporated into the kit if desired.

25mm Velocity Stack = C502D Air Filter

50mm Velocity Stack = C504D Air Filter

90mm Velocity Stack = C604D Air Filter

Please contact us for further information and fitment options.

Below are links to two different engines fitted with two popular bike carb kits (one 1800 zetec with R1 Mikuni carbs, one Ford 2.3 Duratec fitted with ZX9R carbs). The lower lines are both carb sets without trumpets and the higher lines are when fitted with our 50mm trumpets. In both cases significant performance increases (typically 5-9bhp) are seen between 3500-6000rpm when the carburettors are fitted with our trumpet kit. Additionally the torque curve is seen to be much smoother. Note that the Duratec is making peak power very low in the RPM range due to a very restrictive exhaust (soon to be replaced!), but the effect of the trumpets on engine performance is clear. We see so many bike carb conversions running without any trumpets (bike breakers often remove them along with the original bike airbox) - ALL of which would see the benefits highlighted below, probably the cheapest power you can find!

1800 Zetec on 40mm R1 Carbs, no trumpets vs danST 50mm trumpet kit

2300 Ford Duratec ZX9R Carbs, no trumpets vz danST 50mm trumpet kit

Should you have another throttle body diameter please contact us - we may be able to make a similar kit to suit