"performance" air filter hype
03-23-2004, 04:03 PM
#402
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Originally posted by Skeedatl
The air moving in a pipe is exactly what is happening with ram air...air is diverted through a closed environment...the mathematics for pressure work the same for air as they would for any fluid...just the constants are different (which I noted in the calculations). All of the calculations treat it as compressible, and in fact show the amount of compression, which was later verified in an article posted by 1LE, but like Rodabaugh, the amount of conversion taking place is so small that you can call it incompressible until the difference it large enough to be "worth discussing".
It's compressible for the sake of description, my math shows that there is "some" compression going on...but for the sake of description, the amount of compression is so small, that it doesn't make any difference in terms of HP.
It's like measuring MPG. If you get 30MPG or 30.1MPG...it's not going to make a difference. Not that .1MPG is "non-existant" but rather because there are so many other variables that .1MPG is within "uncertainy" in calculating MPG.
At any speed you can move air molecules closer together...but there is a point in which the pressure difference is so low that it doesn't matter. Rodabaugh's argument is that in automotive applications, cars as so slow, that the tiny amount of compression that does occur "doesn't matter" in terms of generating horsepower...that is until you're driving so fast that you are talking about speeds no one goes, especially on the street (where you see ram air applications like the WS6). In that case, you see HP improvements along the lines of ANY CAI, like the Injen CAI.
The air moving in a pipe is exactly what is happening with ram air...air is diverted through a closed environment...the mathematics for pressure work the same for air as they would for any fluid...just the constants are different (which I noted in the calculations). All of the calculations treat it as compressible, and in fact show the amount of compression, which was later verified in an article posted by 1LE, but like Rodabaugh, the amount of conversion taking place is so small that you can call it incompressible until the difference it large enough to be "worth discussing".
It's compressible for the sake of description, my math shows that there is "some" compression going on...but for the sake of description, the amount of compression is so small, that it doesn't make any difference in terms of HP.
It's like measuring MPG. If you get 30MPG or 30.1MPG...it's not going to make a difference. Not that .1MPG is "non-existant" but rather because there are so many other variables that .1MPG is within "uncertainy" in calculating MPG.
At any speed you can move air molecules closer together...but there is a point in which the pressure difference is so low that it doesn't matter. Rodabaugh's argument is that in automotive applications, cars as so slow, that the tiny amount of compression that does occur "doesn't matter" in terms of generating horsepower...that is until you're driving so fast that you are talking about speeds no one goes, especially on the street (where you see ram air applications like the WS6). In that case, you see HP improvements along the lines of ANY CAI, like the Injen CAI.
03-23-2004, 04:21 PM
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Originally posted by Skeedatl
Not good considering you have to do 150MPH to see it.
Perhaps I need to fab up an air box and beat this sh!t out of my TL...for the sake of science.
Not good considering you have to do 150MPH to see it.
Perhaps I need to fab up an air box and beat this sh!t out of my TL...for the sake of science.
There were MARKED increases in power well below that speed, which you'd already know IF you read the articles (which you clearly have NOT).
Look at it this way:
From a dead start on a balls-to-the-wall run, that bike is clipping the 100 MPH mark in ~ 7 seconds.
So in just ~ 7 seconds, that bike is going to begin to see quantifiable gains that wouldn't exist without ram air.:wow:
03-23-2004, 04:23 PM
#404
The computations aren't location specific. Where the compression occurs in irrelevant, only where the envelope of compression exists. And even then, the location isn't necessary for computation.
03-23-2004, 04:24 PM
#405
Originally posted by harddrivin1le
The ~ 6.5% increase in power correlates to 150 MPH.
There were MARKED increases in power well below that speed, which you'd already know IF you read the articles (which you clearly have NOT).
Look at it this way:
From a dead start on a balls-to-the-wall run, that bike is clipping the 100 MPH mark in ~ 7 seconds.
So in just ~ 7 seconds, that bike is going to begin to see quantifiable gains that wouldn't exist without ram air.:wow:
The ~ 6.5% increase in power correlates to 150 MPH.
There were MARKED increases in power well below that speed, which you'd already know IF you read the articles (which you clearly have NOT).
Look at it this way:
From a dead start on a balls-to-the-wall run, that bike is clipping the 100 MPH mark in ~ 7 seconds.
So in just ~ 7 seconds, that bike is going to begin to see quantifiable gains that wouldn't exist without ram air.:wow:
03-23-2004, 04:25 PM
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Originally posted by Skeedatl
The computations aren't location specific. Where the compression occurs in irrelevant, only where the envelope of compression exists. And even then, the location isn't necessary for computation.
The computations aren't location specific. Where the compression occurs in irrelevant, only where the envelope of compression exists. And even then, the location isn't necessary for computation.
But, back to the bike test.
It was seeing 10 mb of positive airbox pressure @ just 80 MPH. That's 2.6 HP.
That bike hits 80 in what - 5 seconds (in a standing start, balls-to-the-wall run).
03-23-2004, 04:27 PM
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Originally posted by harddrivin1le
The ~ 6.5% increase in power correlates to 150 MPH.
There were MARKED increases in power well below that speed, which you'd already know IF you read the articles (which you clearly have NOT).
Look at it this way:
From a dead start on a balls-to-the-wall run, that bike is clipping the 100 MPH mark in ~ 7 seconds.
So in just ~ 7 seconds, that bike is going to begin to see quantifiable gains that wouldn't exist without ram air.:wow:
The ~ 6.5% increase in power correlates to 150 MPH.
There were MARKED increases in power well below that speed, which you'd already know IF you read the articles (which you clearly have NOT).
Look at it this way:
From a dead start on a balls-to-the-wall run, that bike is clipping the 100 MPH mark in ~ 7 seconds.
So in just ~ 7 seconds, that bike is going to begin to see quantifiable gains that wouldn't exist without ram air.:wow:
03-23-2004, 04:27 PM
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Originally posted by Skeedatl
That's all well n' good for a 10s bike. Those seat of the pants gains aren't realized in anything else. How much off yer E/T would you see if you put ram air on your 1LE?
That's all well n' good for a 10s bike. Those seat of the pants gains aren't realized in anything else. How much off yer E/T would you see if you put ram air on your 1LE?
But I've never been a drag racer, anyway.
I like running FROM SPEED.
03-23-2004, 04:28 PM
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Originally posted by kilrb
An increase of.43PSIG is about equivalent to a 1,000 ft elevation change. I don't know about you, Skeedatl, but I can feel a difference of 1,000ft.
An increase of.43PSIG is about equivalent to a 1,000 ft elevation change. I don't know about you, Skeedatl, but I can feel a difference of 1,000ft.
Here it is:
http://home.flash.net/~rfm2/altitude.htm
And with ram air, the faster you go, the LOWER your altitude effectively becomes!
03-23-2004, 04:32 PM
#410
I can't. Pomona is like 850' or something like that and I get the same ET there as I do at a crappy sea level track like Carlsbad or even the 1/8th at Irwindale.
Not until I go to Palmdale so I see any difference at all, 3,000ft or something like that. What's that...nearly 2 PSI below normal or something like that? And even then, it's just a tenth or 2.
Not until I go to Palmdale so I see any difference at all, 3,000ft or something like that. What's that...nearly 2 PSI below normal or something like that? And even then, it's just a tenth or 2.
03-23-2004, 04:34 PM
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Originally posted by Skeedatl
I can't. Pomona is like 850' or something like that and I get the same ET there as I do at a crappy sea level track like Carlsbad or even the 1/8th at Irwindale.
Not until I go to Palmdale so I see any difference at all, 3,500ft or something like that. What's that...2 PSI below normal or somethign like that?
I can't. Pomona is like 850' or something like that and I get the same ET there as I do at a crappy sea level track like Carlsbad or even the 1/8th at Irwindale.
Not until I go to Palmdale so I see any difference at all, 3,500ft or something like that. What's that...2 PSI below normal or somethign like that?
I don't doubt that "ram air" essentially has no impact on ET (or much impact on ET) in drag racing with streetable cars. The average speed of such cars through the standing start 1/4 simply isn't fast enough.
03-23-2004, 04:41 PM
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Originally posted by Skeedatl
I run faster at high altitude, just I just boost it more...and less wind resistence
I run faster at high altitude, just I just boost it more...and less wind resistence
So if the wind resistance is quantifiably less, so must be the air pressure.
03-23-2004, 04:41 PM
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Originally posted by Skeedatl
The computations aren't location specific. Where the compression occurs in irrelevant, only where the envelope of compression exists. And even then, the location isn't necessary for computation.
The computations aren't location specific. Where the compression occurs in irrelevant, only where the envelope of compression exists. And even then, the location isn't necessary for computation.
03-23-2004, 04:44 PM
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Holy buh-jeezus guys... this thread was started on 03-20-2004 @ 02:35 PM???? That's only 3 days and it's already 17 pages and 411 replies long?!?!?!
It's just an air filter! Just hold a kleenex to your nose and breathe... wolla, air filter. What a concept.
Now a supercharger behind that air filter! That's worth at least 20 pages and 500 replies.
We've all seen the commercial on Spike TV... just agree...
K&N, yeah, K&N!
It's just an air filter! Just hold a kleenex to your nose and breathe... wolla, air filter. What a concept.
Now a supercharger behind that air filter! That's worth at least 20 pages and 500 replies.
We've all seen the commercial on Spike TV... just agree...
K&N, yeah, K&N!
03-23-2004, 04:45 PM
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Originally posted by kilrb
The outside air stagnating on the front of the ram air intake increases the pressure inside the entire intake system. The location of the compressed air also comes into play in the pressure drop of the intake system.
The outside air stagnating on the front of the ram air intake increases the pressure inside the entire intake system. The location of the compressed air also comes into play in the pressure drop of the intake system.
Sounds like we need to nominate Rodabaugh to the Offical Club of Ass Clownery.
03-23-2004, 04:51 PM
#418
Originally posted by kilrb
That is, if we compress the air by 2%, the pressure drop of the intake system will be decreased by 4%.
That is, if we compress the air by 2%, the pressure drop of the intake system will be decreased by 4%.
03-23-2004, 04:54 PM
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Originally posted by Skeedatl
That would be true if you had only a finite amount of air.
That would be true if you had only a finite amount of air.
That means a net rise in pressure (a net drop in vacuum).
I think we should ALL be able to agree at this point that "ram air" does offer SOME benefit, perhaps as low as ~ 75 MPH and that its benefit from that point will increase to the square of velocity.
I'll take Ram Air, thanks.
03-23-2004, 05:02 PM
#422
The only thing that matters, is that the TB "sees" the compression. IOW, you can't compress only the front of the airbox. It's either all or none. The location of the source of the force doing the compression, which is at the inlet...doesn't matter. It's irrelevant for computing the amount of compression.
03-23-2004, 05:06 PM
#423
Originally posted by harddrivin1le
"Pressure DROP is DECREASED...."
That means a net rise in pressure (a net drop in vacuum).
I think we should ALL be able to agree at this point that "ram air" does offer SOME benefit, perhaps as low as ~ 75 MPH and that its benefit from that point will increase to the square of velocity.
I'll take Ram Air, thanks.
"Pressure DROP is DECREASED...."
That means a net rise in pressure (a net drop in vacuum).
I think we should ALL be able to agree at this point that "ram air" does offer SOME benefit, perhaps as low as ~ 75 MPH and that its benefit from that point will increase to the square of velocity.
I'll take Ram Air, thanks.
03-23-2004, 05:10 PM
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Originally posted by Skeedatl
Square of the multiplyer of the velocity. Double the velocity, quadruples the pressure seen in the previous velocity.
Square of the multiplyer of the velocity. Double the velocity, quadruples the pressure seen in the previous velocity.
Just think of the Ram Air system you'll be able to afford (and the money you'll still have leftover) now that you no longer "need" aluminum heads.
03-23-2004, 05:18 PM
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Originally posted by Skeedatl
Maybe I'll just put that money down on one of those alien Miller cycle motors.
Maybe I'll just put that money down on one of those alien Miller cycle motors.
All they gain is a mild reduction in pumping losses...I suppose that would equate to a power gain on some level, but nothing that's directly attributable to the higher static compression ratio.
03-23-2004, 05:29 PM
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Originally posted by Skeedatl
Nope, it's gonna run 50:1 on Pepsi...diet Pepsi at that.
Nope, it's gonna run 50:1 on Pepsi...diet Pepsi at that.
03-23-2004, 06:25 PM
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Originally posted by harddrivin1le
Why is it so hard to follow that I don't run air filters for 15,000 miles?
And any K&N I've ever had is FILTHY after ~ 5K miles.
And you're wrong when you state that engines don't make "an effort" when drawing air into the cylinders.
That "effort" (actually a pumping loss) is LARGE at anything less than WOT.
Why is it so hard to follow that I don't run air filters for 15,000 miles?
And any K&N I've ever had is FILTHY after ~ 5K miles.
And you're wrong when you state that engines don't make "an effort" when drawing air into the cylinders.
That "effort" (actually a pumping loss) is LARGE at anything less than WOT.
03-23-2004, 06:37 PM
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Originally posted by Swat Dude
So I take it is filthier than your paper filter. Does that mean its working better???
So I take it is filthier than your paper filter. Does that mean its working better???
Real world testing/results I've seen produced a mix bag of conclusions....
Does't K&N also make ludicrous claims about the # of miles the filter can go before being "serviced?"
It's filthy @ 5,000 miles...
Here is is:
http://www.knfilters.com/filtercharger.htm
"Lasts up to 50,000 miles before cleaning..."
03-23-2004, 06:39 PM
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Originally posted by Skeedatl
Cotton looking "filthy" doesn't mean bad flow, whereas in paper it does.
Cotton looking "filthy" doesn't mean bad flow, whereas in paper it does.
http://www.knfilters.com/filtercharger.htm
"Lasts up to 50,000 miles before cleaning..."
Leave yours in for 50,000 miles without touching it and see how well it flows...:lol2:
03-23-2004, 06:51 PM
#433
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Originally posted by Skeedatl
In my experience cotton looking "filthy" doesn't mean bad flow, whereas in paper it does.
In my experience cotton looking "filthy" doesn't mean bad flow, whereas in paper it does.
03-23-2004, 06:54 PM
#434
Originally posted by harddrivin1le
Look what they claim:
http://www.knfilters.com/filtercharger.htm
"Lasts up to 50,000 miles before cleaning..."
Leave yours in for 50,000 miles without touching it and see how well it flows...:lol2:
Look what they claim:
http://www.knfilters.com/filtercharger.htm
"Lasts up to 50,000 miles before cleaning..."
Leave yours in for 50,000 miles without touching it and see how well it flows...:lol2:
03-23-2004, 08:09 PM
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Originally posted by Skeedatl
Hence, the words UP TO. Try leaving a paper one in there for 1/2 that, tenth that.
Hence, the words UP TO. Try leaving a paper one in there for 1/2 that, tenth that.
What kind of environment would allow that kind of mileage with a K&N (or any other filter)?????
The entire claim is asinine.
03-23-2004, 08:10 PM
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Originally posted by Swat Dude
According to Harddrivin's experiment protocol, just by looking at more dirt on the KN filter than a paper filter run the same amount of miles last year in the desert, one would have to conclude by the presence of more dirt that the KN was working better.
According to Harddrivin's experiment protocol, just by looking at more dirt on the KN filter than a paper filter run the same amount of miles last year in the desert, one would have to conclude by the presence of more dirt that the KN was working better.
In fact, that wasn't ANYONE'S experiment that I'm aware of...
03-23-2004, 09:30 PM
#437
Originally posted by harddrivin1le
I've never seen a paper filter than claimed to be good for "up to 50,000 miles."
What kind of environment would allow that kind of mileage with a K&N (or any other filter)?????
The entire claim is asinine.
I've never seen a paper filter than claimed to be good for "up to 50,000 miles."
What kind of environment would allow that kind of mileage with a K&N (or any other filter)?????
The entire claim is asinine.
03-23-2004, 09:35 PM
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Originally posted by Skeedatl
... With paper I was changing the filter every oil change (5,000mi). I would pull it, hold it up to the light and you couldn't see ANY light through it; it was so nasty. So I'm going about 3x paper between cleanings and probably could go 6x paper between cleanings. If it weren't so easy to clean, I probably would go 30K between cleanings.
... With paper I was changing the filter every oil change (5,000mi). I would pull it, hold it up to the light and you couldn't see ANY light through it; it was so nasty. So I'm going about 3x paper between cleanings and probably could go 6x paper between cleanings. If it weren't so easy to clean, I probably would go 30K between cleanings.
03-23-2004, 09:43 PM
#439
Paper is better at catching fine particulates, making it dirtier faster but the particulates that are harmful to the motor are those over 20 microns, and with that, they both filter pretty much the same in the SAE tests I've seen.
03-24-2004, 12:31 AM
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Who has actually pulled out the air filter in their TL and checked it out? I pulled mine out tonight to take a look. This thread got me curious. My impressions - The filter is higher quality than I expected. It's frame is rigid with a good seal. It fits well and easily. The filter material is much better than I expected - a thicker material that appears to be some sort of fiber impregnated paper. The filter is narrower than I expected, but it is long and has deep pleats that add up to a lot of surface area. The type of material used and surface area indicate that this filter should remove particulate well and airflow should hold up well as the filter accumulates material. The stock filter reminds me of high quality filters I have seen in other industrial applications. It was not like a cheesy FRAM filter. If anyone else has pulled theirs out, I'd be interested in what your impressions were.
The K&N's that I've had in the past were not put together as well as the filter I looked at tonight, but I have not seen the K&N for the TL yet. After examining the stock filter, I have a hard time believing that the K&N is going to offer much improvement. That's just my opinion but it's based on direct examination of the stock filter - for what that is worth.
The K&N's that I've had in the past were not put together as well as the filter I looked at tonight, but I have not seen the K&N for the TL yet. After examining the stock filter, I have a hard time believing that the K&N is going to offer much improvement. That's just my opinion but it's based on direct examination of the stock filter - for what that is worth.