:What you need to consider is that "race car" parts are designed with maximum performace in mind, longevity of the motor (beyond the length of the race is irrelevant). With air filters its about maximum airflow with minimal filtration. The HKS mushroom filter for example, conistently tests best for airlfow but tests worst for filtration. By the looks of that foam filter it will flow well but provide minimal filtration
this is not quite the case with this filter ITG and Piper cross filter will do all you need and will out last a HKS unit .I use PIPER CROSS filter my self and i have used ITG as well for all kinds of mods emerald performance