When buidling an air intake is the largest filter the best (all things being equal such as manufacturer, type of material used etc.) or not necessarily? I'm torn between buying a new K & N filter (very large; over 8" long by 5" wide) or the Apexi Power Filter (maybe 6" long by 5" wide) which looks similar to the SRT filter but has a funnel/velocity stack on top which is great for a ram-air type setup. Not sure which to choose...what do you guys think?

 

No one can add some info on this topic? There HAS to be a performance difference when using different size filters (different volumes). I'm thinking too large of a filter and there goes your low-end power but great top-end...similar to an exhaust. A very large exhaust will kill your low-end but help your top-end. Do you guys agree?

 

Bigger is better as far as filters go.

Lowest possible pressure drop AND the straighter the air flow through the filter. Some K&N filters (and possibly other manufacturers) utilize a bell-mouth at the transition to the pipe section which can increase flow/decrease pressure drop.

This is of course all else being equal. You also want the COLDEST air possible. A sealed from the underhood airbox with only outside air getting in through a large area to prevent pressure drop.

 

I don't think the filter has anything to do with topend low end as much as the pipe diameter. Such as the srt for example, members with the srt claim they lose low end in exchange for top end because of the 3.5 diameter pipe size when most other intakes for the GS, I believe, are 2.5-3.0 inches. As far as the filter, I would think bigger is better.

Quick question, jbrady, can you please explain what lowest possible pressure drop mean? How does that play into intakes? Thanks.

 

My guess is that he means the actual pressure of air going into the intake tube.

Our engines are naturally aspirated. We reply on the engine's piston stroke to suck air in. If we have some sort of restriction (like too small of a filter), it will hinder the engine's ability to pump air in. When there is a restriction, there is less air intake velocity and increase in pressure drop.

Naturally, our NA cars will acheive 14.7psi of air intake at most (sea level). It's important that we try to take advantage of this pressure by not creating a bottleneck in the intake system (filters are usually the culprit).

jbrady, correct me if I'm wrong.

 

Oh ok I see. Thanks for clearing that up

 

Perfect! Thanks for cleaing that up as well GSteg!