Re: What is an open airbox?
Part 4:
I think that it's important to be sceptical of the marketing hype by aftermarket filter manufacturers and their failure to provide ANY comparative dyno results that demonstrate that their product provides some
performance advantage, or at least no loss in performance.
Modern high performance motorcycle engines are the result of countless hours of development work on a dyno by the manufacturer. They are designed as a unit with air flow and exhaust flow optimized together
for each engine configuration. Purposely (say to save costs) using an unnecessarily restrictive air filter in their design will decrease performance relative to their competitors and their marketing advantage.
So, where are the dyno charts from the manufacturers of the aftermarket air filters? If they really improve performance over stock filters across the RPM range then it's really a marketing advantage to
release their design development dyno charts. Without evidence to the contrary, think It's safe to conclude that it is not to their advantage to release any dyno charts or comparisons with other vendors. The
aftermarket air filter market for motorcycles seems to be built on hype by the manufacturers and by the profits to their sellers. They compete on hearsay and testimonies from happy customers or
recommendations from their own vendors- not on proof of superior performance.
That said, after seeing the dyno chart on the Pipercross UK web site for the MPX038 superbike filter and the web information about the filter's construction, I installed a pair in place of the stock filters. I believe
that Pipercross's 2-stage foam filter is currently the BEST FILTER AVAILABLE FOR DUCATI SUPERBIKES when used with a dirt retention oil spray and cleaned regularly.
They are designed to replace the stock filter elements in the stock air intake ducts. If you have the larger aftermarket carbon fiber air ducts, they won't fit (unless they are the Ducati Performance carbon fiber
ducts that use the stock filters). The filtering advantage they have over the stock filter elements is that they use two layers of foam having different pore sizes (one is finer than the stock foam elements), and
they are designed to be oiled, cleaned and reused.
http://www.pipercross.com/
Some Final Words on Air Filters and Performance
An air filter is not motorcycle performance equipment, it is protective equipment. It's function is to prevent dirt from entering the engine and damaging it. Dirt, by nature, is very abrasive and gets caught between
parts that require a precision fit to function correctly.
An air filter that is selected for use on a race bike most often is not a good choice for use on a street bike. A race bike's function is to provide maximum performance and to finish (win) the race. Often the life of a
factory racing team engine is practicing for, and finishing, one race. Then it's rebuilt to restore clearances by replacing any worn parts.
So, an air filter that is used on a race bike is selected using different priorities than one that is selected for use on a street bike. It primarily has to minimize any adverse effect on engine performance while still
preventing the engine from ingesting dirt from a controlled racetrack environment. It has to capture and hold enough dirt without reducing intake air flow (clogging) to finish the race. It has to be accessible enough
to be changed or cleaned quickly under racetrack conditions.
A street bike air filter, on the other hand, needs to function for thousands of miles in a variety of dusty conditions before cleaning or replacement. Consequently, it needs to hold a lot more dirt, and doesn't need to
be nearly as accessible. Performance degradation is important but is still secondary to filter life.
The smaller the dirt particles captured by the filter, the better. Some designs and materials are better at this (filter efficiency) than others.
Whatever approach you or the filter manufacturer take, the underlying issue is that you need to CLEAN the filter before accumulated dirt reduces airflow sufficiently to reduce engine performance and economy.