For those who already have an Ultra Race Plenum or want to make their own, Skunk2 Ultra Billet Race Runners are available separately.

The Skunk2 Ultra-Race Series Billet Intake Manifold, for Honda K20A/K20A2/K20Z1/K24A1 Engines, is the ultimate manifold for high-horsepower street and race engines. Though the standard Ultra Manifold already allows for 8 injectors to be mounted using two fuel rails, we listened to the demands of racers for a Skunk2 Ultra Manifold with a top-side 8-Injector single rail setup. All Ultra Manifolds feature tapered runners with trumpet profiled entries and plenums that have been designed and optimized using CFD and on the dyno. The short tapered high-volume runners combined with oversized plenum runners favor maximum top-end power over lower-end power and response. The best part about this project was that the hard part was completed years ago, when we spent countless hours on the dyno developing the original cast Skunk2 Ultra Manifolds. There was no reason to mess with a great and proven design.