4-1 Header System

This 4-1 header design features four tubes merging into a true collector, complemented by a specially designed megaphone. This setup is optimized to create a scavenging effect, which directly contributes to increasing horsepower and torque. It is built for high-compression, 2.0L and up, fully built engines, and performs exceptionally well with race gas, E85, or nitrous oxide, targeting builds aiming for 250+ horsepower. Fitment is provided for EG, DC, EK, and EF chassis equipped with a B series engine swap. However, due to its full-race nature, some modifications may be necessary. These can include removing the air conditioning system, extending the O2 sensor cable, and potentially utilizing a half-size radiator, a tucked radiator setup, or a slim fan. Included hardware facilitates installation. While reviews praise the welds and value for the price, one user reported a warped header flange requiring machining.