We started using R2C air filters and pre-filters on both of our dirt modified engines this year.  I believe your filters were especially helpful at Sharon Speedway, our weekly Saturday track. It is notoriously dusty and the dust is the gritty, abrasive kind.  A brand new old style filter seemed to clog up after just one show.  Then it was the cleaning, drying and oiling routine just to try and keep some sense of "low restriction.”  On top of that, we still had the air base streaking and dust deposits inside the carb as well.

After we switched, the routine became much easier, no more washing and oil.  Just blow it out and re-install. And the carb was clean and dust free!!   At Sharon, we even started blowing the filter out between qualifying heat and feature on really dusty nights. Before, we had to use 2 air filters, one for the heat and a fresh one for the feature.  Our engine builder was significantly impressed with how clean the inside of the engine was after a tear down at 1000 laps and has started recommending R2C's to his other customers.
We are very pleased with the quality and performance of your filters and it gives us piece of mind on the track that even in the worst conditions, R2C filters give us the best protection, and less restriction than any filter on the market.  Thanks R2C!!