The original factory-fitted exhaust manifold on your car engine allows a significant quantity of exhaust gas to remain inside each cylinder, where it will mix with the incoming fresh air-fuel charge.

When this happens, less air-fuel mixture can fill the cylinder during the intake stroke. Whatever air-fuel mixture that goes in is weakened by the remaining exhaust gas. Less air-fuel mixture due to the lower intake efficiency, and on top of that, a contaminated mixture means that the power output is markedly reduced in each power stroke. Hence, the factory fitted manifold not only reduces engine efficiency, but also limits the fuel economy of the engine by forcing the engine to work harder in order to produce the required power to propel the car.

The remaining exhaust gas also contributes to a higher engine operating temperature, thereby promoting "pinging" or pre-ignition (especially when the ignition timing is more advanced) and shortening the spark plug's life.
Another side effect of a factory-fitted manifold is that when one cylinder is on the exhaust stroke, exhaust gas pressure is exerted on the exhaust port of another cylinder. For example, it has been tested and proven that in a 4-cylinder engine when number one cylinder is expelling exhaust gas, the side effect is that the exhaust gas also produces a strong pressure at the number four cylinder's exhaust port due to reverse flow.

A well designed tuned length 4-2-1 extractor can siphon out the exhaust gas.

This means that when number four cylinder fires and goes into the exhaust stroke, its outgoing exhaust gas has to fight with the prevailing strong pressure from cylinder number one. The piston now has to act as a pump to push out the exhaust gas resulting pumping losses.

How can an extractor improve engine efficiency?
An extractor is not an ordinary piece of exhaust piping. It has to be designed based on engineering formula and produced with accuracy and details to function effectively. The design of an extractor plays an important role in determining the engine's efficiency.

Not all extractors are the same in terms of design as well as functional effectiveness. A badly designed extractor can actually reduce the power output and torque, making the car lacking in acceleration and throttle response as well as increasing fuel consumption.

To ensure effectiveness, PowerZone extractors are designed based on engineering formula. Each and every pipe is calculated for optimum length and size to produce a siphoning effect. When one cylinder is blowing out exhaust gases it produces a vacuum or siphoning effect in the exhaust port of another complementary cylinder. For example, when cylinder one is on the exhaust stroke a siphoning effect is produced in the exhaust port of cylinder four in a four-cylinder engine.

When there is siphoning effect, the piston now no longer needs to pump the exhaust gas out. Thus, the power previously used for the pumping effort is now recovered to propel the car. Furthermore, the cylinder is cleaned of all exhaust gases and hence the incoming air-fuel mixture is now purer and produces more power. Therefore, not only is there a recovery of lost power (pumping losses) but there is actually additional power from the same amount of fuel and air that goes into the engine cylinders.

PowerZone extractors are designed by using formula to get the right pipe sizes and lengths.

Another important factor that has been taken into consideration is the internal surface finish of the pipes and flanges. A smooth polished finish ensures no restriction to airflow. Other factors include bending angles, jointing, and fitting accuracy. At PowerZone all such factors are duly complied with to give maximum performance standards.

Not only can PowerZone extractors improve your engine's performance, they are also designed for maximum torque and power at lower useable engine rpm.

Next time you pick out an extractor make sure that you ask for an explanation on its design. If you cannot get a reasonable answer, be extra careful in choosing the right one. We, at PowerZone, are ever willing to provide sound explanation and detailed discussion on the design and function of extractors, and most of all, a revealing demo on what type of extractors can actually perform.