K&N Air Filter: Power Loss Explained | Posts 32+

Hello everyone!

I've been using a K&N sports air filter (panel filter) in my car for about 1 1/2 years.
For some time now, I've noticed a gradual loss of power in my car, which has an AHU engine in a Passat.
The LMM (lambda sensor) was cleaned, the fuel filter was replaced, but nothing worked!
A few days ago, I read this post here on the forum.
I once replaced the sports air filter with a paper filter.
The sports air filter was cleaned and oiled the day before yesterday after 20,000 km. The paper air filter (original VW, which had been in use for approximately 30,000 km) was only roughly cleaned by tapping it out.
I could hardly believe it, but with a paper filter, my car had significantly more power and torque.
I measured the times in several attempts (60-100 km/h, 4th gear), and they were, on average, about 0.6 seconds better with a paper filter.

Another positive side effect:
With the '10-cent tuning' activated, the car emits only half the amount of smoke!

My conclusion:
SAVE YOUR MONEY FOR FILTERS LIKE THESE!!!

Regards,
Andreas.

Okay, and try explaining that clearly. Could it be that the intake manifolds in the TD engine are tuned for resonance, and that a textile filter might alter that too much?
The very fact that the 'air intake snorkel' primarily serves to reduce noise already proves that there are significant vibrations (noise/sound).

Regards,

Eike.

eike wrote:

Well, and try explaining that clearly. Could it be that the intake manifolds in a turbocharger

are tuned for resonance, and that a textile filter might alter them too much?
The very fact that the "air intake snorkel" primarily serves to reduce noise already proves that there are significant vibrations (noise/sound).


Hi again.

Okay, so I understand that what you're referring to as a "Plattenfilter" is a component designed to fit inside the original air filter housing.

Resonances in the intake manifold are, in my opinion, fundamentally comparable to electrical oscillating circuits. And just like in those circuits, changes in resistance (comparable to a filter) can significantly alter the overall oscillation behavior.
In that respect, the flow resistance of a filter can certainly have an influence on the oscillating air columns in the intake manifold. However, the extent of that influence / what that influence can be -->

It probably also depends on the overall design of the airways.
Similar to electronics, it is likely that significant changes will only be expected if the largest }portion of the total flow resistance in the suction path comes from the filter. In such cases, even minor changes in the filter's characteristics will significantly affect the performance.

Does anyone have any idea how to analyze the charger from a fluid dynamics perspective? Should it be considered as a resistance, an open pipe, or something else...?

If I'm not mistaken, resonance effects only play a role in the area of the (intake) manifold. At the latest after the throttle valve or air intake manifold, the oscillation should be largely destroyed. Furthermore, a vibrating air column needs two clearly defined ends; otherwise, you won't get any resonance.

After 10 years, this question should be resolved.

Please don't revive such old threads anymore .

:Closed: