TracTuff RBB/ RBC Water Neck - V2

K Series V2 Water Neck Flanges are currently on backorder as of August 25, 2025. ETA is September 5th. 

Essentially an OEM replacement upper water neck for the K24A, K24A2, K24A4, K24A8, and K20Z3 when going into a chassis that originally came with a K20A, K20A2, K20A3, K20Z1, and K24A1. Originally made for a customer who wanted to reuse the PRB/ PRC style upper radiator hose in his RSX.

The fabricated K Series water neck replaces the bulky OEM piece with its huge heater core fitting and EGR platform. The water neck starts with a CNC machined 6061-T6 aluminum flange and has a mandrel-bent section of 1.25" tube welded to it that mimics the OEM outlet position. The flange incorporates a 1/2" NPT heater port that can also be used as an outlet if you are not running in-cabin heat. 

The hardware kit includes four M8 socket head bolts, a 90° heater hose fitting, a heater port plug, an EGR Passage Plug, and a pair of o-rings. 

NOTE: Made to Order - Please allow 2-3 Business Days for this product to be made and ship - If you are interested in a specific design that varies from this, please email us at sales@tractuff.com. The accessory port option was originally offered for those looking for a spot to add the factory single-prong sensor (shown), but can also be used to retain the IACV heater loop if you can find the correct fitting. The accessory port selection is optional; I only offer  1/8" NPT or 1/8" BSPT (Honda Single Prong Sensor). The port is angled as shown.