wots the difference between 4-2-1 and 4-1 manifolds? wot are the advantages of either, which would you's recommend? cheers

 

4-2-1 usually give better mid range torque whereas 4-1 give higher top end torque so really 4-2-1 for fast road 4-1 for race

 

Is describes the design of the pipes.

4-1 = 4 pipes into 1

OBX 4-1 and standard 2.0 manifold




4-2-1 = 4 pipes into 2 pipes into 1

Focus central




A 4-2-1 gives better flow and therefore better gains.