All arround us is about performance, so you would like your car to be at little more performant. What will you do first? The first thing to do, a very easy one is to upgrade your exhaust system.
What exactly is Exhaust System
An exhaust system conveys burnt gases from an internal combustion engine and typically includes a collection of pipes. In the most basic sense, the exhaust system just vents waste gases from the engine. Depending on the overall system design, the exhaust gas may flow through a turbocharger to increase engine power, a catalytic converter to reduce air pollution, and a muffler to reduce noise.
In another words an Exhaust System is a great way to build horsepower, free up trapped torque, and improve upon anemic-sounding factory systems.
Exhaust System Components
A typical stock exhaust system is made up of the exhaust manifold, catalytic converter, muffler, and various lengths of piping to connect them all.
1. Manifold or header
The manifold is an assembly designed to collect the exhaust gas from multiple cylinders and combine those flows into a single pipe. Manifolds are often made of cast iron in stock production cars, and may incorporate material saving design techniques. If the manifold is properly formed it can create a scavenging action that will cause all of the cylinders to help each other get rid of exhaust gases. Back pressure can be reduced by making the manifold with smooth walls and without any sharp bends.
On some gasoline engines, a valve (flat metal plate having the same shape as the opening that controls it) is placed in the exhaust manifold to deflect exhaust gases toward a hot spot in the intake manifold until the engine reaches operating temperature.
A header is another name for a manifold, but which specifically refers to an enhanced manifold that has been designed for performance. During design, engineers will create a manifold without regard to weight or cost but instead for optimal flow of the exhaust gases. This design results in a header that is more efficient at scavenging the exhaust from the cylinders.
A muffler is a device in the exhaust system used to reduce noise. When properly matched to the engine, a muffler will not impair engine performance due to exhaust backpressure, which is simply the resistance to exhaust flow.
3. Catalytic Converter
This device is the catalyst for reducing toxic exhaust gasses to safe emissions levels. Oxides of nitrogen, carbon monoxide and hydrocarbons are reduced to acceptable levels by three-way converters and then released into the atmosphere. Older models used removable pellets to reduce exhaust gas emissions, while later versions use palladium and platinum wafer designs to clean up pollutants. The catalytic converter is located in the exhaust system and has an outer shell made of stainless steel. The similarity with a muffler ends there as catalytic converters contain a catalyst made from a noble metal such as platinum, palladium or rhodium. A catalyst is defined as anything that induces or accelerates a change.
It is designed for optimum performance by virtue of their engine management. The fuelling curves designed for these cars are mapped for the back pressure presented by the catalytic converter and exhaust system. Indiscriminate fitting of a smaller aftermarket cat can lead to unbalancing of these settings, and may cause a reduction in brake horsepower or premature failure of the brick.
4. Exhaust Pipes
Exhaust pipe is a general term for several different pipes used throughout the exhaust system. Although configurations vary with different makes, models and engines, there is usually a front exhaust pipe connecting the exhaust manifold to the catalytic converter, an intermediate exhaust pipe connecting the catalytic converter to the muffler, and a tailpipe connected to the outlet of the muffler and serving as the exhaust outlet. Exhaust pipes may be made of standard or stainless steel.
An exhaust pipe must be carefully designed to carry toxic and/or noxious gases away from the users of the car. Indoor generators and furnaces can quickly fill an enclosed space with carbon monoxide or other poisonous exhaust if they are not properly vented to the outdoors. Also, the exhaust gases from most types of machine are very hot; the pipe must be heat-resistant, and it must not pass through or near any combustible materials.
Posible solutions to improve performance
A vehicle’s exhaust system typically snakes its way from the engine back to the exhaust tip. This means the pipe is bent in several places to clear wheels, suspension parts, chassis components and the gas tank. On a standard system, this progressively reduces airflow because the diameter of the pipe is already small, and even smaller where it bends.
On a performance system, you can expect the pipes to be of a larger diameter and mandrel bent. Mandrel bending is a process that retains the diameter of the pipe, even if it’s been bent 90 degrees. The goal is almost a "straight-through" design that maximizes flow, permitting more air to enter and exit the motor.
Cat Back Exhaust System
Cat-back refers to the portion of the exhaust system from the outlet of the catalytic converter to the final vent to open air. This generally includes the pipe from the converter to the muffler, the muffler itself, and the final length of pipe to open air.
Improving exhaust flow out of any motor will improve breathing efficiency and deliver increased power. High Performance cat back exhaust systems deliver upon this promise and create a deep, aggressive tone in the process.
Cat-back exhaust systems are a very popular aftermarket performance enhancement. They generally use larger diameter pipe than the stock system. Good systems will have mandrel-bent turns that allow the exhaust gas to exit with as little back pressure as possible. The mufflers included in these kits are often glasspacks, again to reduce back pressure. If the system is engineered more for show than functionality, it may be tuned to enhance the lower sounds that are lacking from high-RPM low-displacement engines.
Low back pressure muffler
The larger bore may extend right through the complete exhaust system, using larger diameter piping and low back pressure mufflers, and through the intake system, with larger diameter airboxes, high-flow, high-efficiency air filters. Muffler modifications will change the sound of the car’s engine, usually making it louder; for some tuners this is in itself a desirable property.
Systems and apparatus for muffling sounds produced by an internal combustion engine, and optionally catalytically degrading pollutants within waste exhaust gases. The systems and apparatus utilize a bed of particles within a muffling chamber. The gases are introduced using a diffusion tube with holes therethrough. The muffling particles preferably include silica or alumina, which can also catalytically degrade pollutants. Typically, the muffling/reaction chamber is maintained at a temperature in a range from about 50.degree. C. to about 500.degree. C., which is much lower than temperatures within conventional muffling systems for diesel engines. The muffling systems operate as substantially lower back pressure compared to conventional muffling systems. The systems and apparatus can be adapted to be used in combination with diesel engines or other internal combustion engines and industrial burners.
Example: Corvette Z06 PRT Exhaust System
The NEW Z06 exhaust is 3" from the factory, yet it necks down to 2.5" as it enters the mufflers, reducing exhaust flow and performance. The Billy Boat Bullet PRT System is an entirely 3 inch, T-304 stainless steel system, using precision mandrel bends for uninterrupted flow and performance. The system uses the PRT center muffler section for high exhaust flow and enhanced sound control, while the rear section is a 3" version of the B&B Bullet system, using an additional small resonated muffler at the back of the system.
The muffler tips are double walled, 4" round or 4.5" oval. The entire system comes completely polished and the result is a truly spectacular look and sound that gives this high performance sports car the look and aggressive sound which will have heads turning everywhere you go. The new Corvette has perfect mix of performance, sound and style.