Another Soapbox Rant

[ABN_CBT_ENGR]

Originally Posted by bbhero
What would be an example of a membrane type air filter ??

For a car or truck ??

Closet one I can think of maybe a Powercore air filter...


K&N would be one

Basically in industry speak a membrane media is anything made from a fiber ( pressed or woven, natural or synthetic) or felt.

Glazed or unglazed, embossed or not- all kinds.

The rest are micro perforated papers/synthetics

Best for absolute beta is a membrane with a perf core ( best of both worlds but they will lose flow faster)

There are a lot of 'depends" to consider and I use the term "optimum" rather than "best" for an application because I have never seen a "best" and optimum can be broken down into various parameters as required

 

[HangFire]

Originally Posted by Gebo
Every HVAC guy that comes to my house tells me to use those cheap $1 filters in my furnace. Seriously, I just can't do it.

On that topic... most US homes are made with too high air resistance through their supply ducts, and missing or insufficient return ducts.

Adding a high resistance filter turns an inefficient system into a hopeless one.

It took me years to come around, but I use the cheap filters now. No problems.

 

[wemay]

Originally Posted by ABN_CBT_ENGR
Originally Posted by bbhero
What would be an example of a membrane type air filter ??

For a car or truck ??

Closet one I can think of maybe a Powercore air filter...


K&N would be one

Basically in industry speak a membrane media is anything made from a fiber ( pressed or woven, natural or synthetic) or felt.

Glazed or unglazed, embossed or not- all kinds.

The rest are micro perforated papers/synthetics

Best for absolute beta is a membrane with a perf core ( best of both worlds but they will lose flow faster)

There are a lot of 'depends" to consider and I use the term "optimum" rather than "best" for an application because I have never seen a "best" and optimum can be broken down into various parameters as required


Thank you for this fresh perspective.

 

[bbhero]

Do you believe a K & N would be optimum in a regular car or truck ??

I have heard that in a boat circumstance that was true...

 

[ABN_CBT_ENGR]

Originally Posted by bbhero
Do you believe a K & N would be optimum in a regular car or truck ??

I have heard that in a boat circumstance that was true...


Optimum in terms of unrestricted flow or initial filtration?

Here's another quirk about filtration people don't understand the significance or importance of.

"Flow" ( in volume) is determined by the ratio of 2 main categories.

The size/volume of all capillaries over the total area then the ACFM of the vacuum pulled. ( vacuum defined as lower pressure than atmosphere so the atmosphere "pushes' its way into)

So you could take that same exact filter and housing and put it on 5 different sized engines at 5 different speeds and you would have 5 different sets of efficiencies.( assuming all dust factors remained equal)

So true "optimum" would be a filter that allows full flow on demand over all ranges of operation while providing acceptable filtering and retention.

That's difficult to define for K&N or any other because it would take literally side by side testing of units drawing a set vacuum on a trailer pulled through a desert and other places then analyzing. ( costs money)

Legitimate Tests I have looked at ( other than Farm Project) anecdotally indicate that the K&N type filters tend to provide more flow (resulting in HP)

Similar legitimate tests anecdotally indicate they don't filter on the beta quite as well.

Some maintenance reports show the oil saturation damages sensors.

I personally believe all of those claims have a high degree of reliability but don't tell the whole story because there is significant data unavailable that I would require to make sure something was optimum for an application.

I have one on my H2 and Rubicon and never had any issue but I have to say I didn't have any issues before either so I can say they "perform to expectation" in my applications but I have seen no evidence personally of any inherent superiority or optimal performance in MY application.

It really depends on what attributes you personally consider optimum for your application.

 

[ZeeOSix]

Originally Posted by bbhero

In say a air filter would it be correct to first define what size particles are the most damaging ??

Say 10-20 microns in size.

Once one has the answer to that question then would it not be good to have a efficiency/efficacy goal for particles of that size ?

Say 98-99.5 percent.

And finding a air filter that comes as close as possible to actually meeting those desired goals and or expected efficiency/efficacy per a ISO fine dust testing.

Maybe ISO fine dust testing is not exactly like real world conditions... But what else could one go by?

Just wondering what would be "best" practice...


If you're not going to go by the official ISO test data then what are you going to go by - Project Farm, lol? Air filter and oil filter efficiency tested per ISO test procedures define what sized test dust is used. Yes, it's a much more extreme test than what filters see in real world use, but comparing ISO efficiency is still comparing filter performance on equal ground. Comparing their efficiency any other way would just make it even more confusing.

Anyone that says a filter that tests bad in the ISO test but is an equal or better performer compared to other ISO tested filters of higher efficiency isn't grasping the purpose of comparing filters tested under the same test procedures and specifications. I'm still waiting for someone to prove that a filter that tested low in efficiency in the ISO lab test performs just as good or better in the real world than a filter that tested much higher in efficiency in the ISO test.

bbhero - you've been around here long enough to have seen the correlation between ISO efficiency ratings on oil filters and UOA ISO particle count data. Also been SAE papers showing the correlation ... it's been posted many times. Since there is no easy way for every day Joes to monitor the performance of an air filter on an engine, the ISO efficiency data is basically all you have to go by. And I'd much rather use an air filter that rates pretty high in ISO efficiency that has less inHG pressure drop at 300 CFM than one that rates worse.

 

[wemay]

I don't think ZeeOSix's and ABN_CBT_ENGR's points are mutually exclusive.

 

[Redright9]

Every HVAC person I have ever spoken to says use the cheapest filters for your home furnace. They say the restriction and strain on the furnace from the "better" filters isn't worth it. Especially since people constantly open doors and windows letting in dirt. They also say every house "leaks" air to some degree, so again, no filter is going to stop that or make a real difference other than in the pocket book. So I have used cheap filters for a long time since that's what the guys servicing them say to use.

 

[BMWTurboDzl]

Originally Posted by ABN_CBT_ENGR
Originally Posted by bbhero
Do you believe a K & N would be optimum in a regular car or truck ??

I have heard that in a boat circumstance that was true...




Legitimate Tests I have looked at ( other than Farm Project) anecdotally indicate that the K&N type filters tend to provide more flow (resulting in HP)





Unfortunately in the real world more airflow doesn't equal more HP on a stock tune especially with forced induction.

 

[adamsoil]

Originally Posted by BMWTurboDzl
Originally Posted by ABN_CBT_ENGR
Originally Posted by bbhero
Do you believe a K & N would be optimum in a regular car or truck ??

I have heard that in a boat circumstance that was true...




Legitimate Tests I have looked at ( other than Farm Project) anecdotally indicate that the K&N type filters tend to provide more flow (resulting in HP)





Unfortunately in the real world more airflow doesn't equal more HP on a stock tune especially with forced induction.


Yes, but it takes less time to spool

 

[Job]

Denso, (three layer construction), Fram Ultra, Wix , ACDelco, Baldwin, Purolator highest, or OE. None of the Parts Mister etc Prontos of the world. How much time do you want to spend on it? Trust the maker's name. You buy a new car, the filters are engineered for it and they do have the expertise.
Adding layers of differing efficiency does create a less restrictive filter for a longer time than an equivalent single uniform layer. Some air and oil filters have that.

 

[ABN_CBT_ENGR]

Originally Posted by BMWTurboDzl


Unfortunately in the real world more airflow doesn't equal more HP on a stock tune especially with forced induction.


I'm fully aware of that which is why I put it in brackets.

PTO HP is a marriage and result of many moving parts and processes in an ICE and intake air is only one of them. (a very important one and significant contributor true- but not the do all end all)

 

[ZeeOSix]

Originally Posted by BMWTurboDzl
Originally Posted by ABN_CBT_ENGR
Originally Posted by bbhero
Do you believe a K & N would be optimum in a regular car or truck ??

I have heard that in a boat circumstance that was true...

Legitimate Tests I have looked at ( other than Farm Project) anecdotally indicate that the K&N type filters tend to provide more flow (resulting in HP)

Unfortunately in the real world more airflow doesn't equal more HP on a stock tune especially with forced induction.


Depends on the car's ECU and sensor system design. If it has the ability to sense more air flow and optimally adjust the fuel then there will be added HP. Same thing goes when adding a high flow intake and/or exhaust system. Many new high performance cars (ie, Corvettes) use sensors that will allow the ECU to self adjust to those bolt ons without a tune and it results in decent HP gains. Just like the thousands of dyno tests that have been done showing HP gain by just dropping in a less restrictive air filter or bolting on intake and exhaust systems without a tune. Add a tune and you can get even more HP ... in fact, just add a tune to a bone stock FI car and you can typically get more HP over the conservative factory tune.

I stopped using K&N filters many years ago after deciding that the lose in filtering efficiency wasn't worth a few extra HP at WOT near redline.

 

[DGXR]

First, you can't compare a furnace air filter to an automotive air filter. Obviously they are totally different applications but also the consequences for cheaping out on a furnace filter are much less than the consequences for cheaping out on an automotive filter, I would argue. The only way to tell if the aftermarket air filters are just as good as OEM is to conduct a test -- I think they have a number / category for that test so that it's done consistently in every test of this kind.

In my mind it's just not worth the hassle of agonizing over which brand is good / better / best. I just decide what level of filter I want to run and I get the model that provides the best quality and lowest price at that level of filter. For example, if I wanted to run a premium oil filter, I would get a Fram Ultra and not a Mobil 1 EP even though they are basically in the same category.

For non-critical replacement parts, I will often use aftermarket (oil filters, air filters, spark plugs, hoses, belts, tensioner/pulleys, etc).
For critical parts or drivetrain items I usually go OEM or major premium brand (MOOG, AC Delco, Denso, etc).

 

[Gebo]

Originally Posted by DGXR
First, DGXR] ...

For non-critical replacement parts, I will often use aftermarket (oil filters, air filters, spark plugs, hoses, belts, tensioner/pulleys, etc).
For critical parts or drivetrain items I usually go OEM or major premium brand (MOOG, AC Delco, Denso, etc).


I have a very different definition of "non-critical" and "critical" parts. I consider every part on my vehicles as "critical." Even the floor mats.

That makes sense if I only use OEM or Moog. Warped mind from 3 concussions.

 

[WyrTwister]

Originally Posted by CT8
Usually a major brand would be a good choice.

This .