Has anyone tried K&N Engine Air Filters?

Thanks Shawn, I think he is a lost cause, it might be best to let it go, anyone with half a brain will see what we are saying and I think they will also see that someone knows they are wrong but isn't mature enough admit it yet.

Anyone reading this if you still believe a low resistance air filter will save a road car any gas please re-read the thread and think again. If that doesn't do it then I'm sorry, I can't help you.

I'm out of this one, you can only say the same facts in a different way so often then it gets boring.

 

And I suppose the increase in manifold vacuum from zero inches of mercury at WOT to 21 or so inches of mercury at closed throttle idle is NOT a change in manifold pressure?

You are now reaching back for your primary vent effluvia and throwing it at the wall just to see if it sticks!

The rest of your post is almost complete BS! There is no accurately applied scientific fact in it.

Some facts:

1. Varying throttle angle and air mass adjusts fuel input into the air stream. Higher air mass inputs more fuel. Lower air mass inputs less fuel. The computer control, remember? Leave out the influence of dual exhaust oxygen sensor inputs.

2. Air mass flow is raised or lowered by throttle angle. A more closed throttle allows reduced air mass flow, a more open throttle allows increased air mass flow.

3. Internal manifold pressures vary depending on mass flow and throttle angle. Higher mass flow at a given throttle angle will produce LOWER pressures than at lower mass flow. The corollary; lower mass flow at more open throttle will produce higher pressures. That is PRESSURE, not VACUUM. Higher vacuum number is lower pressure, lower vacuum number is higher pressure. All that mumbojumbo about easing off the throttle to get the same pressure is ultimately misleading.

4. Reduced fuel/air mass means reduced fuel consumption. For a given power output a fixed amount of fuel is required only in ideal, constant systems. An ICE is not a constant system. Closing the throttle, reducing the air mass flow, to produce the same power output, uses less fuel, no matter what the dynamic cause of that closure.

5. YOU are the person originally stating that the only result of reducing intake air resistance, a K&N filter, is a more closed throttle at the same power output. You completely ignored the corollaries.

DUH!

As I have previously stated,

"Your insistence on disconnected analysis is leading you astray."

You are NOT conducting investigations on any Prius, you are sucking disconnected, and irrelevant, numbers and conditions out of your primary vent.

The logic is very simple, and universally stated,

"Reducing power waste in any engine causes that engine to produce more usable power. You reduce power waste by reducing operating resistances, one of which is gas flow resistance."

"Reducing power waste increases fuel efficiency!"

"K&N filters save both your wallet and the atmosphere!"

You have neither disproved nor countered those logical, and factual, truths.

"Trying to blind 'em with science or baffle 'em with BS doesn't work. The proof is at the checkered flag, or the timing lights, or the lap counters. Or, in this case, at the gasoline pump AND the parts counter."

Just as an aside, the temperature here in Wyoming is hovering around zero degrees Fahrenheit. My gas mileage is back over 50 MPG. I get that mileage by mildly preheating intake air, closing off the grill opening, and thereby reducing power wasted to heat the under hood and incoming air, and reheat coolant, using combustion heat which is power equivalent in the motor system. If I allow full ambient temperatures through the radiator and under the hood I would be down to around 40 MPG. I know this because I did not make the changes until the temperatures went into the 50s for a couple of days following a long cold period.

I expect you might now try convincing us that all those folks, like long distance truckers, who buy grill blockers are wasting their money, that saving power by reducing energy waste does not increase fuel efficiency.

 

Sure it is a change, but in doing so you are also changing the engine load. That's the part you have yet to grasp. The throttle is controlling your manifold pressure. You can reduce or increase the DP before the throttle, and the throttle will have to move in the appropriate direction to give you the same manifold pressure at a given load. We are talking about identical loads (fixed or dynamic doesn't matter, the power profile needed to drive the loop at fixed speeds and acceleration rates is unchanged.)

Like I said, your Occam's razor claim reduces down to removing the throttle altogether for maximum efficiency. Obviously that wouldn't work as the engine would be running full out, burning fuel just as fast as it could. But so far you haven't connected the dots. It all looks disparate to you because you don't yet see the continuum. You are thinking in discrete components rather than system wide.

You erroneously seem to think that manifold pressure/mass flow is fixed by throttle angle. It is not. It would be if the upstream pressure was CONSTANT (and rpm was constant.) However, it is NOT constant.

Throttle angle sets a resistance factor, not the actual pressure or even the differential pressure. (Ditto for the filter, the filter box, the snorkel, etc.) So throttle angle is not setting a precise air flow or fuel flow. Again, look at altitude for reference that is easier to visualize real world, at 10,000 feet the absolute pressure is ~20.6 inches of mercury. So at 10,000 feet even at WOT you will have additional loss through the snorkel for the filter box, the filter, entrance/exit effects of the box, and the fully open throttle valve.

Thinking in terms of vacuum is prone to mistakes. You need to be able to think in terms of absolute pressure and mass flows. Vacuum measurements work off a differential, but you need a fixed reference, and in this case it is floating. I've run into this same sort of problem many times with folks selling or specing large process compressors and blowers (whether they are engineers or tech reps.) They mis-spec because they think in their own niche's short hand/terminology. That often doesn't mesh with what process design folks are requesting. If noboby mediates/translates the equipment won't function as designed. Both sides think they are saying the same thing, but they aren't. I know because I've both caught the mistakes before purchase on new equipment, and fixed/retrofitted them after purchase on older equipment when we debottlenecked.

 

Utter gobbledegook and bullsh*t, non-responsive to my multiple, detailed, factual arguments in the post you selectively quote.

You can crawl back under the bridge you crawled out from, you troll from the Midwest. Is that a Detroit River bridge?

 

You are more than welcome. I say that in the name of all those who did not come back and those who did come back with parts missing. I'm just one of the latter.

 

Sigh.

In other words you still don't understand how it works and won't expend the mental faculties to learn either. It's only "gobbledegook" to you because you are being intellectually lazy or are just plain stupid.

Your other points don't matter as the single big hole in your basis negates all of them. I've pointed out in exhausting detail where you have gone astray, but all you can respond with is namecalling. You are the troll.

p.s. As your norm, you've guessed really wrong about location.

 

My guess was the spirit of your location. You are still a troll who misdirects Prius owners away from real savings, both of maintenance expenses AND fuel expenses.

 

Gentlemen,

You have long passed the point where any useful information has been
exchanged.

You are now using the bottom-feeding tactic of personal attacks.

I suspect that many, like me, hope you can see what's happening and decide
to end the food fight.

How about you?

 

That is accurate,

and acceptable.

 

There is a Prius site that, among other things, details the operation of the Prius PZEV engine, (in)efficiencies, pumping losses, Atkinson-Miller cycle engines, offset crank shaft, and such other peculiarities as they apply to Prius operations.

http://www.ecrostech.com/prius/original/PriusFrames.htm

Click on the link

http://www.ecrostech.com/prius/original/Understanding/InternalCombustion.htm