well, remember that intake length adds to total manifold volume. it makes a difference on the tq and hp curves accordingly.
Yes and no, it would add to the total length on a independent throttlebody injection system, but it doesnt really help on a car with a manifold that has the thottlebody on one side of the manifold (your typical EFI car). Why, since the pulse of the intake charge wont reflect back the same path it came out from, thats why itb injection has trumpets, its for pulsecharging the intake charge. But yes, on a itb injection having actually longer intake tubes, can increase your power. A general rule is, the less the car revs the longer the tubes should be (ofcourse to a limit), but generally the pulse length should be shorter, so it would move faster on an engine revving higher, hence shorter tubes, or trumpets, etc whatever you want to call them should be. Its physics really

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And by eliminating the restriction of directing the air through the stock air box, allow more air intake. Or would that throw off the atomization of air by not having the designed air flow to allow proper swirling?
Well, the stock air box isnt really that restrictive, most should be a bottle neck only at a relatively high tuning level. How would you allow more air intake? a NA engine uses vacuum to fill the engine with air, you cant really force any more than the engine can suck into it and yes, there is enough air in the stock intake airbox for the engine to suck and still leave some left over air in the manifold.Thats the limitation of the NA engine, you can only have so much air going into the cylinders, doing foolish stunts on the intake can actually ruin the performance, Id rather go for a set of camshafts if I was in your shoes, than spend money trying to re-invent the intake tract. Oh and about the swirl, you dont really think you can make the air swirl inside the intake manifold? Only time it needs to swirl is in the cylinder when it has mixed with the gasoline charge and is waiting for the plug to ignite the mixture. Then again most engines are designed to give atleast some swirl to the fuel air mixture inside the cylinder for a uniform combustion.