Originally Posted by DaveB

That I do not know. I know there are quite a few cars that do come with airboxes equipped with cone filters. Off the top of my head, I know the S2000, first gen 5.3 V8 Vortecs, and the newer Viper come this way. I've been debating for a while about picking up a used Stillen CAI and adding additional paneling to completely seal the airbox.

According to COBB Tuning, EVERY intake they've tested (Stillen, Injen, JWT, AEM) including their own intake, messes with the A/F ratios to the point that the engine often looses a little power. I've always respected companies with honesty like this. There aren't many out there.