Stock exhaust manifolds are usually made of cast iron and can be restrictive. Exhaust gases from each cylinder build up back pressure within the manifold which affects the next cylinder.
Instead of a common manifold that all of the cylinders share, each cylinder gets its own exhaust pipe. These pipes come together in a larger pipe called the collector. The individual pipes are cut and bent so that each one is the same length as the others. By making them the same length, it guarantees that each cylinder's exhaust gases arrive in the collector spaced out equally so there is no back pressure generated by the cylinders sharing the collector.
We can provide high quality stainless steel manifolds that improve the above process resulting in improved engine performance.