FRAM filters for Traxxas REVO and JATO are now in the lineup at Hi-Velocity.  These filters have unbelievable performance gains, and reign supreme over traditional foam filters.
 
To begin scientifically testing filters, I use a specially designed flow bench calibrated for low CFM flows in the hobby industry.  This flow bench is capable of measuring and graphing intake and exhaust CFM, inches of water, pressure per square inch, and air speed, as well as air sweeps, which is a custom design.  The dyno is a custom-built machine, calibrated specially for hobby engines.  All testing is performed by Gary Cornwell.
 
Bringing Technology to the Starting Line 
The first test is to determine the intake airflow (or CFM) into the engine at max speed.  An air horn has been built and calibrated to measure CFM from the intake side of the engine.  The air horn is slightly larger than the carburetor, so as to not impede the air flow.

The test showed 7.1 CFM was flowing through the intake side of the engine at WOT on the dyno/air flow text.
 
Now that I have the correct CFM demand from the engine, I now have to check the CFM through the stock Traxxas filter.  The flow bench is used for this test, by simply sealing up the filter on the flow bench test plate.

Clean TRX Filter

4 Lap Dirty TRX Filter

The stock filter flows 3.2 CFL new and clean.  After 4 laps on a dirt track and a ¼ tank of fuel, the filter flowed 2.6 CFM.
 
Something interesting happened during testing, because the filter stayed in front of me during the test.  I was able to see the sponge start to compress, due to the dirt and oil on the outer surface.  As I continued with the testing, I found that the dirty filter curve was expediential.  That restriction accounts for a great deal of unnecessary, continuous fuel adjustments.