B Series Megaphone Race Header Side Fender Exit B18 B18 B18B B18C1 B18C 4-1 CollectorProduct Features: This is a full race Side exit header for Honda Acura B series engine. 4 1 Design, 4 tube merge into a true merge collector and then it's got a specialty designed megaphone at specific location to create a scavenging effect to increase HP and Torque. Our header is design for high compression build engines 2. 0L and up fully build engine race gas and E85 is a big plus or nitrous. This header is perfect for any one shooting for 250+hp.