Exhaust Manifold

Header Pipes and Exhaust Manifolds From XLMOTO

A motorcycle's combustion chamber takes a lot of effort to convert air and gasoline into an explosive mix. The resulting detonation then pushes the piston down the barrel. By-products are exhaust gasses that rapidly exit the system. These gasses enter the header pipe or exhaust manifold. This steel tubing bolts onto the cylinder head's exhaust port. It takes spent exhaust gasses away from the motorcycle via the silencer and for modern machines, this journey includes a quick tour of the catalytic converter. Modern header pipes are difficult to manufacture. So has this prevented aftermarket manufacturers from offering alternatives? The opposite is true; aftermarket manifold systems and exhaust pipes are more popular than ever.

Why Change the Header Pipe?

Appearance: Mass-production means that the pipe bending and welding on a stock exhaust manifold is carried out on computer-operated machinery. So while consistency isn't an issue, the finished product is not comparable to handcrafted TIG welds.

Cost: Most factory replacement exhaust systems are more expensive than aftermarket brands. This plus point makes them a cost-effective alternative.

Ground Clearance: It's possible to build an aftermarket header pipe without a catalytic converter, to hug the underneath of the motorcycle closely. This feature allows for increased lean angles.

Sound: Although a less restrictive silencer dictates sound, an aftermarket header pipe allows the exhaust gasses to flow faster, giving the exhaust a crisp sound.

Weight: Mass-produced stock exhaust systems are bulky and heavy. By comparison, aftermarket exhaust manifolds and pipes are handmade in small numbers from lighter-weight materials. When combined with the omition of a catalytic converter, weight savings of 50% over stock systems is typical.

Materials

For aftermarket performance header pipes, it's stainless steel or titanium.

Stainless steel is strong, bends well, is easy to weld and doesn't rust. For mid-to-top-shelf exhaust manifolds, this type of steel alloy is a favourite.

Titanium is the go-to metal for exhaust systems when weight saving is an issue. Titanium is around 40% lighter than stainless steel and offers more heat resistance.