4-1 T3/T4 Merge Collector with Short-Side Wastegate Entry (1.5″ Sch10 304SS)

Speed up your manifold build times and guarantee maximum exhaust pulse velocity with our 4-1 T3/T4 Merge Collector with Short-Side Wastegate Entry.

• Proudly Designed & Cut in the USA: 100% CAD designed and CNC cut in house for laser accurate runner alignment and tight, zero gap fitment right out of the box.

• 1.5″ Schedule 10 304 Stainless Steel: Machined from high grade 304SS Sch10 pipe for extreme thermal resistance, structural strength, and long term fatigue protection under high boost.

• Integrates Short-Side Wastegate Entry: Features a heavy-wall 2″ Sch10 wastegate runner integrated directly into the short side of the collector to optimize wastegate flow and prevent boost creep in top mount configurations.

• T3/T4 Flange Port Match: Precision contoured to seamlessly transition into our CNC machined T3 and T4 turbine inlet flanges (sold separately) for maximum exhaust gas velocity and minimal backpressure turbulence.

• Ideal for B-Series Top Mounts: Specially proportioned for Honda B-Series top mount manifold layouts (EG, EK, DC2 chassis).

• Ready for Fabrication: Unassembled and pre-cut to save you hours of tedious hand-grinding, mitering, and fitting... simply align, tack, and TIG weld.

Engineered for Superior Boost Control & Flow

Proper wastegate positioning on a 4 into 1 merge collector is critical for preventing boost creep and maintaining stable manifold pressures under full load. By placing the 2″ Sch10 wastegate entry on the short side of the collector, exhaust gases are diverted directly into the wastegate path with minimal flow disruption to the turbine wheel. It's the ultimate time saving component for professional fabricators and DIY builders aiming for 700+ HP results.