On 11/4/2019 at 12:12 PM, eisfeld said:

 

1. increasing the amount of space that lets air through (the holes) while keeping the surface size of the material the same

2. increasing the surface size of the material. Since you can't just make the filter bigger you could have more folds etc

 

 

1 hour ago, eisfeld said:

 

Does not have to be. I gave some examples of how one can achieve increased airflow while keeping filtration performance the same.

Seems like only #2 fits the bill.

#1, increasing hole size will let bigger particles pass.

Nice try tho.

Certain oils e.g., certain esters, are highly polar, 

and will attract & capture particles electrostaticly.

K & N knows this.

1 hour ago, papa al said:

 

Seems like only #2 fits the bill.

#1, increasing hole size will let bigger particles pass.

Nice try tho.

Certain oils e.g., certain esters, are highly polar, 

and will attract & capture particles electrostaticly.

K & N knows this.

Seems like papa didn't read all of my post.

 

Quote

The first case results most likely in less dirt being filtered and more entering the engine unless the hole diameters are kept the same but the amount of holes is increased

 

Nice try tho!

 

Your point about materials is valid also of course. That can change the performance as well.

Airflow? Has anyone mentioned that some air boxes restrict flow more than the actual filter?

21 minutes ago, VocalNeal said:

Airflow? Has anyone mentioned that some air boxes restrict flow more than the actual filter?

Good point to consider. How often is that the case?

13 minutes ago, eisfeld said:

Good point to consider. How often is that the case?

It is bike specific. I.e. Some older bikes with CV carbs. require a bit of negative  

pressure in the airbox. 

Some airboxes have baffles to mitigate induction roar.

12 hours ago, eisfeld said:

Seems like papa didn't read all of my post.

 

ouch

papa well spanked

????

 

also

as the filter loads up 

even smaller particles will be trapped

[more significant in oil filters tho]

https://www.researchgate.net/publication/305109858_Effect_of_OEM_Style_and_Aftermarket_Performance_Air_Filters_on_Vehicle_Parameters

"The filtering efficiency test conducted on OEM and K&N air filter shows that OEM air filter exhibits superior air filtering qualities compared to K&N filter."

"3.3 Air Discharge Test.
 
Fig 3. Percentage Resistance to Air Flow. Fig 3 shows that K&N filter exhibits higher resistance to air flow compared to OEM filter in both new and clogged condition. Here the air flow resistance offered by air filter box in no filter condition is taken as the reference, the resistance offered by remaining filter conditions are calculated with respect to that of no filter condition."
 

1 hour ago, VocalNeal said:

require a bit of negative  

pressure in the airbox. 

Technically ///   absolutely;

No such thing as negative pressure

0 psi/bars is as low as it goes.

Normal average sea-level atmospheric pressure is 1.01325 bars

A total vacuum = 0 bars.

I do a lot of bike tuning  ,for myself and other people , the main effort inincreasing HP is to increase air flow and fuel deliveryregulation ,in carbs or EFI,

 

For instance my Ducati S4  definitely flows a lot more air using the K&N filter  and apprpriate  fueling maps   ,, but when increasing performance   to 119hp from original 101hp  on standard ducati paper air filter   and maps   i do have to  change engine oil more often ,, thats no big deal for almost 20%  power gain ,, that particular bike has been ridden accross SEA often on very dusty roads ,, but engine wear is minimal and acceptable it is also smoother running and nicer to ride than with factory maps .

 

it is a trade off ,, the ducati paper filter is better at cleaning off dirt and dust but performance and smooth running   was not acceptable

 

 

in the end