Welterweight Race Cars-
Air Filter Technology

Despite the fact that today’s sport bike engine is built for both speed and reliability, the stock air filter is one component that is not up to the task of powering a welter-weight racing car. The air filter’s primary purpose is to supply clean air to the engine, however the air flow and filtration demands placed on a filter during normal street riding are far less than the demands placed on the same filter in a welter-weight racing application. Higher RPMs for longer periods of time and harsher operating environments, like the dust and grime of a dirt track, require increased airflow and filtration efficiency.

The Kinser Air Filter in a 600cc Honda F4 mini-sprint application.

 Simple Illustration
The best way to illustrate the importance of air to an engine’s performance is to look at one of the most impressive engines in existence, the human body. Envision a human subject using a straw to breathe through while completing a few simple tasks. The first task is to walk from one end of the hallway to the other. For most individuals, the amount of air supplied through the straw is enough to accomplish this task. Now let’s require the same individual to sprint a mile breathing through the same straw. The increased amount of energy required to successfully complete this task will make it very difficult, if not impossible for the individual to complete the task at peak performance. In fact, it is very likely we’ll find our subject passed out on the side of the road.

The task of supplying air to the engine of a street bike during typical riding conditions can be compared to the task of supplying air to the human body as it walks from one end of the hall to the other. Little air is required to successfully complete the task. The task of supplying air to an engine powering a welter-weight racing car can be compared to the task of supplying air to the human body while it sprints one mile. A significant amount of air is required to complete the task at peak performance.

Increasing the flow of air into an engine will increase both horsepower and throttle response. However, it is not as simple as merely providing the maximum amount of air to the engine. If that air contains dirt, dust or other debris, the life and performance of the engine is adversely affected. For this reason, filters must perform the difficult task of allowing the maximum amount of air through, while blocking the maximum amount of dirt, dust and debris—a delicate balancing act.

The Problem-Paper Filters Just Don't Stand Up
In addition to fulfilling the requirements of air flow and filtering, the filter in production motorcycles must also fulfill two additional requirements: cost containment and convenience. As a result the paper filter found in a stock air box doesn’t maximize the performance of an engine but merely meets the minimum requirements. These filters are cheap to produce and easy to handle, making them the perfect fit for the typical consumer. In applications, like welter-weight racing, where there is a need for increased air flow and increased filtration, standard paper filters simply don’t stack up. Paper filters work on a “Go—No Go” principal. Paper filters are essentially flat surfaces with openings that allow air to pass through. Dirt smaller than these openings is allowed through, while dirt larger than the opening sticks to the surface, clogging the filter and restricting air flow. The result is continually decreasing airflow. Unfortunately, since paper is weak and swells when it comes into contact with moisture, cleaning is virtually impossible. Even blowing the filter out with compressed air can result in tears or damage to the filter that further reduces its effectiveness.

The Solution
Speed Partz has partnered with Kinser Air Systems to bring welter-weight racing the same race proven technology that dirt track racers like J.J. Yeley, Travis Rilat and Critter Malone use on their cars. Kinser Air Filters employ a major advancement in air filtration technology—open cell filter foam. Foam air filters combine great airflow capacity with huge dust holding capacity that can capture even the smallest of particles. Additionally these foam filters are much easier to maintain since they can even be washed in soap and water. In early testing, competitors have gained as much as an additional 200 RPMs after installing the Kinser Air Filter System.

Easy to Implement
Kinser Air Filter and Speed Partz are making it easy to obtain and implement this technology on your car. Systems are currently available that will easily install on mini-sprints, dwarf cars, modified midgets, TQ midgets,

A base plate, filter foam, cage and outer wear are all included with the Kinser Air Filter System. A pre-filter is optional, but is strongly recommended for most dirt track applications.

micro-sprints, go-karts and more. Kinser Air Filter Systems make use of a base plate, domed cage, filter foam, pre-filter foam (optional) and an outerwear. Base plates are available pre-configured for several of the most popular applications, or can be sent out as blanks that can be easily drilled to fit your specific application. Kinser Air Filter Systems start at $149.00. For more information contact Speed Partz at 513.874.2034.

© 2002 Speed Partz L.L.C.