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Discussion Starter #1
Comparing a drop in filter to a cone,surely the drop in has the larger surface area,would this not make it more effective or is having a shorter CAI tube more helpful.


TIA for any opinions
 

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It has indeed been shown that the drop in K&N increases airflow and produces the same if not better gains than any CAI kits. The stock airbox seals off very well to prevent heat from getting in which many of the CAI kits don't seem to do as good of a job.
 

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The K&N drop in adds about 3 extra HP and the K&N CAI adds about 12HP, the Airaid adds 15 HP. Airaid and K&N oiled filters are the best at removing the smallest particles of dirt and Airaid has just released their synthamax non oiled filters which are supposed to be just as good as the oiled filters.
 

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The K&N drop in adds about 3 extra HP and the K&N CAI adds about 12HP, the Airaid adds 15 HP. Airaid and K&N oiled filters are the best at removing the smallest particles of dirt and Airaid has just released their synthamax non oiled filters which are supposed to be just as good as the oiled filters.

Those number are no where near correct. That is like magic dreamworld where Racing stripes add 25 horsepower.
 

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Discussion Starter #5
thanks for the unput so far.
Do you think that the shape of the cone allows for more organized airflow(greater volume) to the engine compared to a flat filter?

Maybe i am overthinking this but aside from looks and wanting your engine to sound like you have a huge air leak i am not seeing how i can justify dropping the coin on a CAI.
 

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I read a test in a Import magazine where they tested 5 or 6 CAI systems on a honda Civic and the stock airbox ran the fastest quarter mile time. For what ever that is worth.
 

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go with any high quality drop in (I use a K&N).
An after market intake will provide a smoother tube which will be a benefit and they do look better.
However performance gains are minimal either way.
Unless you're going for the whole smash on performance upgrades dropping a ton of $$$ on an intake is not a smart investment.
More bang for just a little more buck with a predator.
my 2 cents
 

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surface area is easy to calculate. what is the length and width of a stock filter? 8' by 10"?? 80 sqin. whats the length and width or the diameter of a cone? i have no idea. give me some numbers and Ill calculate it
 

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The part where it gets dicey is if the number and depth of the pleats are substantially different between the 2 shapes. The pleats can modify the effective surface area of the basic shapes.
 

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Most CAIs are only good for about a 5 hp increase. I bought the MOPAR CAI for its looks and better intake sound. CAIs costing $300+ are not your best bang for the buck when it comes to increased performance.
 

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after thinking about this for a minute, i wonder if filter area matters at all.... the inlet tube size will be the limiting factor. if the tubes are the same size and are smaller than the filter area, shouldnt that be the biggest restriction? as long as the filter is big enough and flows free enough, you can start talking about the flow thru the tube
 

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when carcraft test the K&N filter against a brand new paper filter, they saw zero gains. their conclusion was a new clean paper filter was just as good as the K&N. however, they also said that the paper filter would clot easier and quicker and then become more of a restriction, much sooner than the K&N's cotton filter
 

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after thinking about this for a minute, i wonder if filter area matters at all.... the inlet tube size will be the limiting factor. if the tubes are the same size and are smaller than the filter area, shouldnt that be the biggest restriction? as long as the filter is big enough and flows free enough, you can start talking about the flow thru the tube
Air can speed up appreciably with negligible increase in drag inside a tube to fulfill flowrate. As long as it isn't reaching extreme "terminal velocity" sort of speeds, it should be fine. The filter is more critical because it IS highly influenced by air velocity. That is why you typically want a large surface area of media...to ensure the local air velocity is very slow and triggers the least amount of drag as the air passes through the media, for a given level of filtration. Once through, the air can speed up appreciably through a smaller tube with little negative impact to fulfill flowrate needs.

As for sizing the tube after employing the "ideal filter", I suppose it comes down to nailing down exactly what the needs are for the particular engine?...otherwise it is much shooting in the dark. Maybe a good target would be to match the size of the throttle body? I would reiterate, though, that unless it is an extreme situation, endeavoring to equalize a bit of mismatch in tube size will probably yield very little, if any, benefits.
 

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The K&N does in fact give a HP increase My SRT on a dyno jet gained 8.5 HP
I pulled 376.22 RWHP and 375.07TQ after the K&N install then after a custom tune I pulled 387.61RWHP and 388.00TQ
 

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again a good read on the dyno results but not a very consistent way in which the runs where made.
dollar for dollar appears the e-bay is the best bang for the buck since you have to spend three to four times the money to get two times the HP bump with a brand name.
I went back and forth a few time between an e-bay intake and stock box with K&N drop in.
Finally decided on the stock box which I custom painted for a look I really dig.
 

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i would think so. i mean if you rolled a stock filter up into a cone (or even a cylinder), its diamter would be something like 3"- much smaller than the ig side of the cone filter. maybe the same size as te small end of the cone
 

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If anything, I like the reusability of the filter. I install K&N in everything I own just for that sake. I'd be curious too if a larger inlet tube would help. Probably not on these computer controlled monsters, but on an old computer controled carb 305, increasing the snorkel size and running hoses to under the front bumper slashed a half second off that tub's 0-60. 11sec down to 10.5!!! WOOHOO! lol
 

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If anything, I like the reusability of the filter. I install K&N in everything I own just for that sake. I'd be curious too if a larger inlet tube would help. Probably not on these computer controlled monsters, but on an old computer controled carb 305, increasing the snorkel size and running hoses to under the front bumper slashed a half second off that tub's 0-60. 11sec down to 10.5!!! WOOHOO! lol
It all depends on where the restriction is. If the restriction is the Throttle body nothing you do will matter unless you get a ported/larger TB.
 
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