I'm getting tired of my dirt caked gauze filters. If you have used a foam or "mushroom" filter could you please share your experiences. Thanks in advance for your help.

 

I've used ITG foam filters in my open-wheeled race cars, they seem to do OK even at notoriously dusty tracks like Willow Springs. The more important thing will probably be to get a high-quality foam filter if you're going to use one (don't buy the chinese ones on ebay). In street cars, I just used factory paper filters. I use paper because it provides the cleanest air for my engine, there are numerous tests on the subject that confirm that the more flow you get through a filter, the dirtier the air will be. So over time, dirtier air will cause more hp loss due to crud buildup, thus negating any power gains.