Not a thing wrong with asking. Nothing wrong with debating the issue either. I have a dual on both my cars and I think they make a difference per my 1/4 miles times. I had the single CAI in the beginning. I traded it back in for a dual. When I purchased the 2nd car, I went right to the dual. A single does just fine, but I swear from the beginning, having just driven from Indy to Detroit, Rob installed the dual later that night, and I did a few interstate runs. Low end there was a difference. Can you duplicate his work. I think you can get close with the right parts. If you pay yourself nothing for the research, chasing down the parts, and the fab work. You can save a few bucks. Look at Max's (Cichon). His is beautiful. I would never run foam. That would be like the foam we used to use when I raced motorcycles. After one heat, it was filthy. Switched out run another heat. Can you imagine the draw on a piece of foam from a S/C? No thanks. And no, I won't debate that. It's a $12K hand built motor. Why do that? BTW. I have driven thru down pours at speed and these filters work just fine. No moisture is let in to cause hydro lock. This was debated long ago when Rob first started building the single.