Surefire Exhaust Manifolds Versus Headers

Cast Iron Exhaust: Manifolds Vs. Headers

Replacing a cast iron manifold with a header is a common path to more performance. However, there are a few things to take into consideration before making this modification to a vehicle.

Performance

The primary advantage of headers over cast manifolds is the increased performance of headers. Headers flow more efficiently than manifolds and allow exhaust gases to exit the motor more quickly, increasing the potential for horsepower and torque.

This can be a good or a bad thing, depending on what you want.

Appearance

Headers are generally considered to be better-looking than cast iron manifolds, which look rather clunky and unrefined when compared to the sleek "bundle of snakes" appearance of a nice header.

When it comes to emissions, headers may not be legal on pollution-controlled vehicles. Check your local laws before installing a set of headers on a street vehicle.

Noise

Headers can be far noisier than manifolds. Cast iron manifolds muffle the exhaust sound due to their heavy, thick construction. Headers have a thin-walled construction that transmits noise much more easily.

Heat

Manifolds produce less heat than headers, which have thinner walls because of their tubular metal construction. The added heat is not good for nearby mechanical components or for performance, which is why headers are frequently ceramic-coated or wrapped with header tape.

Legality