AIR FILTERS - SAVING TURBOS AND ENGINES SINCE THE 1920S.
When internal combustion engines became mainstream in the late 1800s, the need for clean air to maintain engine efficiency was recognized by the builders and mechanics of the day. The earliest engines often ran without any kind of filtration, relying on manual cleaning of intakes, but when it was found that dust and debris would cause engine wear, reduced performance and more frequent maintenance the need for air filtration was identified. In the 1920s, the first rudimentary air filters appeared as simple wire mesh screens to block large particles. These were mostly ineffective against finer dust but marked the beginning of air filtration in vehicles. Oddly, we still see these on some modern drag cars, because racecar. Things changed in the 1940s thanks to better engineering and cleverer people on the job. Oil-bath air filters were introduced around this time, they used an oil reservoir and a mesh element. The air would have to pass through the oil, trapping particles, but the airflow was quite restricted. They did the job but they were also bulky, messy, and needed lots of maintenance - and people are lazy. In the automotive boom of the 1950s, someone tried new materials, and the paper-based air filter was born. These filters used pleated paper treated with resin, a design so good that it’s still used today. The best part was that they were now disposable, a serviceable item. A jump to the 80s saw an improvement in design and technologies in most industries, and so synthetic fibres and foam-based filters were added to the mix. Foam filters became the choice for motorsports and off-road applications.
In the 90s, things stepped up a level and brands like K&N and BMC started coming to the forefront. These featured reusable cotton gauze treated with oil. These filters had better flow, which meant increased performance. While they were disposable, they were also reusable after a wash and re-oil. They’re an alternative to the paper filters that come standard in cars and are often the first modification someone does when they buy a car, from a Mk1 Golf to a McLaren 720S. They come in flat or cone configurations and are available for most cars. But… How good are they? How much flow do they give over stock? Do the ones that flow better have good enough filtration to keep the nasties out? There are plenty of ways to test this, some scientific and some using logic. Years back I was involved in an air filter test, we put the usual big brand woven filters up against foam filters. In that test, the foam stuff made more power, but when we put suction through them and sprinkled dust, too much got through the foam. When we published the results we were threatened with legal action. Times have changed though, testing is easier and thanks to social media, a well-documented test is hard to dispute. We stumbled across this recent air filter test from Brand Ranks, and the testing was done with the help of an actual engineer. Is this credible? You decide. What we do know is that if you’re adding in an aftermarket filter, stick to a top brand and ignore the cheapies from China.
Take a look at the YouTube video that shows how the chaps from the popular testing channel Brand Ranks went about testing a bunch of well-known aftermarket air filter brands with the intent of giving them a rating to keep you, the consumer as informed as possible: The ULTIMATE Air Filter Test [Engineer Tested] | Brand Ranks
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