[Scott Clarke]

Alex-
Porsche doesn't do anything that isn't optimized for performance. It is very difficult to improve on the original equipment. The stock airbox is a Helmholtz resonator that boosts mid-range power with only a VERY slight reduction of top end power.

In a similar fashion, the stock muffler is very good with MFI. when I purchased my car it had a two in, four out Abarth muffler. It sounded great, but was too loud. I replaced it with a stock unit. I did measured acceleration tests before and after, and discovered that the stock muffler was much quieter, and produced measurably improved acceleration times.

All that said, I do have PMO/K & N twn air filters on my MFI now. You can't beat the sound or the look.