The Roush is pretty good in this area also. It uses the duct aka "scoop" at the end of the grille, it seals off to the bottom of the hood (more or less) and the only other opening is at the front, below the edge of the hood.
What we really want is
1) cold air
2) more of it
and the Roush design looks about as good as it can get
I wonder if anyone ever compared the area of the duct (aka scoop) in the grille, to the area of the MAF tube? Everyone always wants a bigger MAF tube, but everyone seems to be completely ignoring that all the air has to come in through that duct in the grille, so if the tube is bigger (in area) than the duct, then the duct becomes the limiting factor. Or, you have to pull hot air from the engine compartment and that defeats #1 above.
Actually the Roush is one of the worst intakes to buy on the market for power gains lol. The filter sucks in all the hot air it doesn't seal on the hood like you think it would. Our factory intakes are pretty good and AEM is the only company to improve upon it. Most open filter design intakes actually lose power.
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