Air Filter with best Filtration

[Job]

The intake on an engine takes in a volume of air over time, measured in cfm usually. Restriction has different units, pressure, and isn't cfm. When an air filter restricts so the pores are less than needed cfm then it needs to be changed. This is also proven by the theory a dirty filter filters better. It is more restrictive due to blocked pores, but as long as the pores are meeting cfm, all is well. That's how I see it, keeping it simple.

http://filterminder.com/resources/l...-air-filter-service-indicators-work.html

 

[ZeeOSix]

Units of measure have nothing to do with it. It also has nothing to do with "as long as the pores are meeting cfm".

Every air filter has flow restriction, even when brand new. The more restrictive the filter is, the less CFM a given engine will be able to suck in while at WOT. Less air sucked in means less HP. That's as basic and simple as it gets when talking about normally aspirated engines.

So do you think an engine is going to make the same amount of HP at WOT regardless of the air filter's flow restriction?

If Filter A has more pressure drop at WOT than Filter B, do you think the engine will suck the same amount of air at WOT and make the same HP? You think the pressure sensor downstream of both filters will show the same readings at WOT? Why do you think people see a HP increase from just dropping in a K&N air filter into the stock airbox?

 

[Job]

Peace on earth and good will towards men is all I can say to this.

 

[ZeeOSix]

Bottom line - the filter flow resistance (delta-p) does affect a NA engine HP output at WOT. Not rocket science.

 

[circuitsmith]

Air pressure at sea level can push up a column of mercury about 30 inches, or a column of water about 408 inches.
If an air filter and intake plumbing to an engine reduce that pressure by 11 inches of water that's a decrease of 2.7%.
Which means the air going into the (naturally aspirated) engine is 2.7% less dense than with no restriction.
And thus 2.7% less power.
So the most a 200hp NA engine could gain by going from moderate restriction to no restriction is 5.4 hp.

 

[ZeeOSix]

Yep ... a 2.7% HP increase is a lot better than a 0% HP increase.

 

[Job]

Originally Posted by circuitsmith
Air pressure at sea level can push up a column of mercury about 30 inches, or a column of water about 408 inches.
If an air filter and intake plumbing to an engine reduce that pressure by 11 inches of water that's a decrease of 2.7%.
Which means the air going into the (naturally aspirated) engine is 2.7% less dense than with no restriction.
And thus 2.7% less power.
So the most a 200hp NA engine could gain by going from moderate restriction to no restriction is 5.4 hp.


Restricting air doesn't change it's density. If you can explain that please. Altitude changes oxygen and air density and is why power changes with altitude given the same air mixture. Drive a VW van air cooled to the Grand Canyon and it's pedal to metal going 50mph at those elevations. The throttle body and throttle plate vary the air flow which is measured usually in cfm. That determines the power output. Restriction in the air filter, which is psi not cfm, has nothing to do with reducing air flow UNTIL the total pore area is less than the throttle plate opening in the throttle body. These air minder things show restriction, then when it gets to a certain point it's time to change air filters. People advise to let air filters get dirty because the efficiency increases, with no mention of power reduction, because it takes quite a lot of dirt to cause reduction in power., using theengine for what it was designed for.
Another thing is companies like Nissan know all about making power. They design limits to what the engine can produce and be reliable. If someone wants to gain a hp by running no air filter with the throttle plate wide open and maximum rpm, it's a free country.

 

[ZeeOSix]

Originally Posted by Farnsworth
Restricting air doesn't change it's density. If you can explain that please. Altitude changes oxygen and air density and is why power changes with altitude given the same air mixture.


You almost basically answered your own question. But reduced air pressure does reduce the air density, including the oxygen content. Just like going higher in elevation reduces air pressure.

A pressure drop across the air filter is essentially like going up slightly in elevation (ie, a reduction in ATM absolute pressure). Measure engine HP at WOT with a new filter, then again with a very clogged filter having much more delta-p across the filter. Guess which situation gives more HP.

Less absolute air pressure at the throttle body inlet means less CFM going into the engine - that's basic physics of air flow. A more restrictive air filter and intake duct system means less absolute air pressur at the throttle body. Less air going into the engine means less HP. Basic physics of NA engines, and the relation between an absolute pressure air source and engine VE (CFM intake) and HP output.

 

[Job]

Originally Posted by ZeeOSix
Originally Posted by Farnsworth
Restricting air doesn't change it's density. If you can explain that please. Altitude changes oxygen and air density and is why power changes with altitude given the same air mixture.


You almost basically answered your own question. But reduced air pressure does reduce the air density, including the oxygen content. Just like going higher in elevation reduces air pressure.

A pressure drop across the air filter is essentially like going up slightly in elevation (ie, a reduction in ATM absolute pressure). Measure engine HP at WOT with a new filter, then again with a very clogged filter having much more delta-p across the filter. Guess which situation gives more HP.

Less absolute air pressure at the throttle body inlet means less CFM going into the engine - that's basic physics of air flow. A more restrictive air filter and intake duct system means less absolute air pressur at the throttle body. Less air going into the engine means less HP. Basic physics of NA engines, and the relation between an absolute pressure air source and engine VE (CFM intake) and HP output.

Everything is more complicated in real life. Take your air plumbing off the Taco, you believe it will make more power. You know more than Toyota. Of course if the air is blocked entirely the engine stops immediately, zero power. You know how oil speeds up through small channels and slows down through large, pressure drops and increases along the way, with the same flow.
Here's a graph in reality. It's diesel of course. They seem to spec about 25 inches of water and the red flag comes up.
http://filterminder.com/resources/l...l-information/133-hp-vs-restriction.html

 

[ZeeOSix]

Any flow restriction reduces the absolute air pressure at the intake of the throttle body and results in less CFM of air being ingested, so any air flow restriction means less HP. It's that simple. Go do some research on the internet ... there's tons of info on intake systems and how less intake restriction give NA engines more HP at WOT.

The bottom line is that EVERY air filter and air intake system has flow restriction - some being more restrictive than others. Why do you think some aftermarket air intake & filtering systems make an engine develop more HP than a stock OEM system? When you increase the HP output by 3~5% on a 450 HP engine, you're talking about a 13~22 HP gain. Halltech intake systems on Corvettes showed that proof over and over on dyno testing. Plenty of info on the 'net about it - Google it.

So yeah, some people know more about intake systems than the OEM engineers. But keep in mind that those OEM systems have other design requirements around them, such as intake noise levels, etc, so the OEM systems are not optimized for breathing and max potential HP. Some are good, but still not ideal from what is could be. And yes, there are even aftermarket intake system for the Tacos, which increase HP output. Basically about any OEM intake system can be improved for more engine HP, because less restiction in the intake system results in less delta-p which results in more CFM going into the engine at WOT. It's pretty basic physics.

 

[Job]

Originally Posted by ZeeOSix
Any flow restriction reduces the absolute air pressure at the intake of the throttle body and results in less CFM of air being ingested, so any air flow restriction means less HP. It's that simple. Go do some research on the internet ... there's tons of info on intake systems and how less intake restriction give NA engines more HP at WOT.

The bottom line is that EVERY air filter and air intake system has flow restriction - some being more restrictive than others. Why do you think some aftermarket air intake & filtering systems make an engine develop more HP than a stock OEM system? When you increase the HP output by 3~5% on a 450 HP engine, you're talking about a 13~22 HP gain. Halltech intake systems on Corvettes showed that proof over and over on dyno testing. Plenty of info on the 'net about it - Google it.

So yeah, some people know more about intake systems than the OEM engineers. But keep in mind that those OEM systems have other design requirements around them, such as intake noise levels, etc, so the OEM systems are not optimized for breathing and max potential HP. Some are good, but still not ideal from what is could be. And yes, there are even aftermarket intake system for the Tacos, which increase HP output. Basically about any OEM intake system can be improved for more engine HP, because less restiction in the intake system results in less delta-p which results in more CFM going into the engine at WOT. It's pretty basic physics.


You may know more than Toyota engineers , or quote people you think know more, about everything, but you said nothing about the graph showing you are wrong. By a company specializing in restriction gauges. There it is no hp loss, in fact it shows a little increase. Go study more on the internet. Seems sort of latched on. Go right ahead and talk more. In real life it takes about 25 inches of water for the pores to be restricted enough to matter. That's all I need to know about maintaining our cars in real life. I may buy one, but actually at 50k my filters look good still, no restriction that would change anything.
Bickering over before the lock. Talk more all you want.

 

[ZeeOSix]

Originally Posted by Farnsworth
Originally Posted by ZeeOSix
Any flow restriction reduces the absolute air pressure at the intake of the throttle body and results in less CFM of air being ingested, so any air flow restriction means less HP. It's that simple. Go do some research on the internet ... there's tons of info on intake systems and how less intake restriction give NA engines more HP at WOT.

The bottom line is that EVERY air filter and air intake system has flow restriction - some being more restrictive than others. Why do you think some aftermarket air intake & filtering systems make an engine develop more HP than a stock OEM system? When you increase the HP output by 3~5% on a 450 HP engine, you're talking about a 13~22 HP gain. Halltech intake systems on Corvettes showed that proof over and over on dyno testing. Plenty of info on the 'net about it - Google it.

So yeah, some people know more about intake systems than the OEM engineers. But keep in mind that those OEM systems have other design requirements around them, such as intake noise levels, etc, so the OEM systems are not optimized for breathing and max potential HP. Some are good, but still not ideal from what is could be. And yes, there are even aftermarket intake system for the Tacos, which increase HP output. Basically about any OEM intake system can be improved for more engine HP, because less restiction in the intake system results in less delta-p which results in more CFM going into the engine at WOT. It's pretty basic physics.


You may know more than Toyota engineers , or quote people you think know more, about everything, but you said nothing about the graph showing you are wrong. By a company specializing in restriction gauges. There it is no hp loss, in fact it shows a little increase. Go study more on the internet. Seems sort of latched on. Go right ahead and talk more. In real life it takes about 25 inches of water for the pores to be restricted enough to matter. That's all I need to know about maintaining our cars in real life. I may buy one, but actually at 50k my filters look good still, no restriction that would change anything.
Bickering over before the lock. Talk more all you want.

... sure, a more restrictive air filter INCREASES horsepower. Nice cherry pick attempt, but more going on there than what it appears (diesel held at constant RPM, not at WOT). Now go do some more research about all the dyno tests that show noticeable HP increases on gasoline engines at WOT with less restrictive filters and intake systems.

Start here, and that's improving an already good OEM intake system on high performance engines:
https://www.halltechsystems.com/default.asp

Maybe you should email Halltech and tell them they can get more HP if they make their filters and intake systems more restrictive.

 

[ZeeOSix]

Looks like Toyota Racing Development (TRD) doesn't know what they're doing when it comes to improving the stock OEM intake system. Maybe it's more restrictive, lol.

https://parts.toyota.com/p/Toyota_2...r-Intake-System/69551041/PTR0335160.html

 

[Job]

That's how graphs make it look some times, against reality, was actually my point. Power didn't decrease tho even with slight data error fluctuations. Because they design engines so a filter can load to a point and the power will be maintained. Notice cars come with an hp rating at rpm. Tell the loaded air filter is more efficiency boys their engines are losing lots of power. That's up to you to want to exceed it or not with a supercharger or whatever way. Write a letter to filter minder telling them you know more.

,
I going take the screens off all my winders this summer cause when the wind blows thru I want thick air in the house for breathin good. Learnt a lot on it in this here. Another idee is I have a coach filter in my car and when I keep the winders shut I dont want to be gasping for air cause it's so thin. Take that coach filter out and throw it away.

War over you win take victory lap.

 

[ZeeOSix]

Originally Posted by Farnsworth
That's how graphs make it look some times, against reality, was actually my point. Power didn't decrease tho even with slight data error fluctuations. Because they design engines so a filter can load to a point and the power will be maintained. Notice cars come with an hp rating at rpm. Tell the loaded air filter is more efficiency boys their engines are losing lots of power. That's up to you to want to exceed it or not with a supercharger or whatever way. Write a letter to filter minder telling them you know more.


The problem with your reference to that diesel engine dyno graph is that test was done at a constant 1500 RPM (noted at bottom of the graph) ... it was not done at wide open throttle (WOT). If they would have shown the throttle position at those different filter restriction data points you would have see that the throttle plate position was being opened up more to maintain the same HP output, so it's another apples to oranges misconception latch-on comparison.

Go back and watch the video in this earlier post ... that's what this discussion is about. Less air flow restriction at WOT means more engine HP. There's literally thousands of dyno tests on the internet that prove it.
https://www.bobistheoilguy.com/foru...-filter-with-best-filtration#Post5336301

Originally Posted by Farnsworth
I going take the screens off all my winders this summer cause when the wind blows thru I want thick air in the house for breathin good. Learnt a lot on it in this here. Another idee is I have a coach filter in my car and when I keep the winders shut I dont want to be gasping for air cause it's so thin. Take that coach filter out and throw it away.

Yeah, when you take the screens off your windows or the cabin air filter out you reduce the flow restriction and you get more air flow ... just like when reducing flow restriction on an air intake system at WOT will result in more air flow and more HP. As for the rest ...

 

[circuitsmith]

Originally Posted by Farnsworth
Restricting air doesn't change it's density.


Sorry F, you're misguided from this first sentence onward.
Any restriction in the filter or intake plumbing has exactly the same effect as slightly closing the throttle.
Some thoughts on the ongoing exchange:

If air is being taken in pulses it's possible to make the length and diameter of the intake plumbing such that more air is taken in than no plumbing at all.
It's a tuning/resonance effect. Close the throttle some and/or share multiple cylinders and the pulsations disappear.
The HP variations of the diesel may be due to changes in intake resonance.
Diesels don't have throttles BTW.

 

[Job]

Originally Posted by circuitsmith
Originally Posted by Farnsworth
Restricting air doesn't change it's density.


Sorry F, you're misguided from this first sentence onward.
Any restriction in the filter or intake plumbing has exactly the same effect as slightly closing the throttle.
Some thoughts on the ongoing exchange:

If air is being taken in pulses it's possible to make the length and diameter of the intake plumbing such that more air is taken in than no plumbing at all.
It's a tuning/resonance effect. Close the throttle some and/or share multiple cylinders and the pulsations disappear.
The HP variations of the diesel may be due to changes in intake resonance.
Diesels don't have throttles BTW.

I realize I was technically wrong and admit it. Some of this stems from argument and people not understanding tolerances. Like thinking a 20 micron particle in real life is exactly 20 microns. I know diesels have no throttle plate and work by varying fuel mixture. Had three diesel vehicles and had to do engine work myself on one way back in time.
Now that everyone is wearing face masks they must know how much harder it is to breathe through the restriction. But if the mask were giant sized we wouldn't notice it even tho technically there is a restriction, even through a window screen.
Manus have a horse power rating and design engines to perform to the standard up to some air restriction point. The intake runners are restrictions, the valve openings are restrictions. In practice the meter minder people seem to think leave a filter on to get better efficiency and change it when the restriction goes to the red zone which seems to be about 25 inches of water on their gauge.
Throttle bodies and carburetors have a cfm rating. Put a smaller on get less hp. The way I see it air filters are over sized for the use intended so that they can go a long time and still not significantly effect power.
So I learned at least I admit it, that should be a good thing? Seems these days more and more it is not.

 

[ZeeOSix]

Originally Posted by Farnsworth
The intake runners are restrictions, the valve openings are restrictions.

Throttle bodies and carburetors have a cfm rating. Put a smaller on get less hp.


Yes, and all of that comes into play effecting the VE (volumetric efficiency) and hence the HP output of a NA engine at WOT throughout the RPM range.

 

[The_Nuke]

So what's the consensus, K&N for the win?

 

[ZeeOSix]

Originally Posted by The_Nuke
So what's the consensus, K&N for the win?

K&N for a bit more flow in exchange for a bit less filtration efficiency.