BMW E30 M3 S14 race pakosarja

4-2-1 manifold for racing use. Wide power range. Pipe diameters (mm): 50.8-> 57.1-> 63.5. Material steel. Thermal isolating TechLine BlackSatin coating. Lamda sond boss at collector outlet pipe.

Collector part is fitted with springs. That eliminates the risk of primary pipe cracking due to engine movement. Also that makes it possible to tune power range. Shortening of seconary pipes will move power range to higher revs.

Recommended exhaust system size 2.5" or bigger.  

Choose universal pipes, curves and silencers to build the exhaust system. https://martelius.com/en/universal-parts