Custom Exhaust Systems

Superior Quality Custom Built Free-flow Performance Exhausts

Goch and Cooper have superior quality custom built free-flow performance exhausts, branches, headers, manifolds, downpipes & silencers. Our big advantage in this industry is that we are able to offer a Dyna test with the system if required or even an optimisation “tune” to guarantee best results.

The existing exhaust system is replaced with a custom built free-flow system up to 76mm.  The new system is routed the same as the original and is supported by the same hangers. Visually the systems may look the same but the difference is in the diameter of the tubing and the construction of the silencers. The new exhaust system allows the air to be scavenged from the engine more efficiently, without compromising the comfort of reduced noise levels inside the vehicle.

Catalytic Converters The fact being however that very little people actually understand the subject or even know how a “Cat” looks. Over the past few years, catalytic converters have been a point of discussion in many workshops, group debates, arguments, etc.

The chief priority on the engine’s exhaust side is to complete combustion of the remaining unburned fuel. This is the function of the catalytic converter. The converter supports secondary combustion of CO and HC to form non-toxic carbon dioxide (CO2) and water (H2O) while simultaneously reducing the exhaust-gas-borne nitrous oxides (NOx) to neutral nitrogen (N). Catalytic treatment is much more effective than processes such as purely thermal secondary combustion in which pollutants are burned out in a hot flame.

The catalytic converter assists in converting over 90% of the pollutants into harmless constituents. The three-way catalytic converter reduces all three pollutants – CO, HC and NOx – at the same time. It features a tubular ceramic support surface with a noble metal coating that usually consists of platinum and rhodium.

The platinum and rhodium accelerate the chemical reduction of pollutants as the exhaust gas flows through the unit.   A blocked or destroyed catalytic converter will definitely reduce the power output and negatively influence fuel consumption. If a catalytic converter is installed, it is essential that unleaded fuel be used, as lead destroys the catalytic properties of the noble metals. The point is, leaded fuel and catalytic converters cannot work together.