qbix

if you are revving faster through the gears that would mean your car is accelerating faster and that means that your engine is much stronger.
From a different air filter... You have swallowed a huge placebo pill!

neanicu

Yeah,I gave up on trying to explain...

When an actual vendor agrees the main benefit is sound,what else is there to say...
The sound is better because at full song you hear the air rushing through the air box more intensified,but the car is making the same power and torque.
What's funnier is the clogged filters argument...of course if you have clogged filters in this car,in any car for that matter,you are chocking your engine for air and putting a new clean filter OEM or not,will give you the impression it runs better...BECAUSE IT DOES!

The RS is using BMC filters in conjunction with a whole set of modifications,including larger displacement,to make more power,it is not making that power because of the filters...LOL!

odwa

Best place to purchase BMC filters?

bronson7

So is it worth the $$$ difference?

robmypro

I would like to know also, in addition to any performance benefits at altitude.

fxz

go for it's $150+1work hour, a no brainer,every 2k or 3k miles give it a clean,
just ppl not owning a real 9k GT3 can write that BS

RealityGT

Hello my fellow Ontarian....Placebo.... Unless you want induction sound.. then you should try and find a high flow dry filter.
This will do nothing for you. You need Forced Induction.

bronson7

Thank you.

STG

If these filters have no benefit, why are they used in the RS and all the Porsche Motorsports cars?

Plus OEM for many exotics.

robmypro

Thanks for the response. I am probably thinking about this wrong, but if a dirty air filter produces less power than a clean one, this would be because airflow is restricted. Increasing airflow with a BMC filter might not produce much improvement because a clean air filter already provides adequate airflow, given the design of the engine.

But at altitude, air is restricted due to the lower consentration of oxygen. So the engine in essence already has a very dirty air filter on it. In this particular case, I would think increasing airflow would be beneficial, as the engine is receiving far less than optimal air at altitude.

Feel free to point out the flaw to my logic. It's never stopped my wife.

neanicu

I think perhaps you guys should give the BMC filters a try,see how you like them and if you feel an improvement. If you are really OCD and have plenty of time on your hands,you should swap the OEM filters out at a shop where they have a Dyno in place. Do a run with the OEM filters,if they are relatively new/low miles and not clogged up. Then do a run after the BMC filters have been installed. See if there's a difference... It can't hurt anything.

I personally feel like I'm speaking to a brick wall,plus " I don't own a state of the art 9K RPM engine ". One thing to note is that I am certainly not a Porsche motorsports expert and I might be wrong...I'll admit my mistake when the 2 comparing Dynos have been posted by an independent owner,in the conditions I have described above.

robmypro

A before and after dyno would end the discussion. Agree 100%.

Mike in CA

I'm no expert on this but logically it doesn't seem like a freer flowing filter would make a difference at altitude. A NA engine can only "breathe" in so much air based on it's displacement and other design factors and as long as the stock filter is adequate for the demands of this air flow at sea level, a lower restriction filter won't make a difference at altitude. In that case, air flow isn't the limiting factor, it's the oxygen in the air flow. As was mentioned FI, not a freer flowing filter, is what's needed at altitude. Just my thought....

Mr. Adair

This ^

Wow, just wow...

The high quality BMC filters are better and stock on the RS because:

1. They are more durable, washable, reusable than OEM paper
2. Yes, a clogged OEM paper filter can hinder intake performance
3. It takes an awfully dirty and unchecked filter (years) for this to happen
4. A clean OEM paper filter doesn't flow less than a BMC
5. Sound is a benefit, yes.
6. Yes, you can over oil and reduce air flow

Increased HP from intake improvements is a very very complicated equation and it is always the sum of many things that includes air in and air out and is always a sum of a complete tune working together. Lastly, it is almost impossible to out engineer a company like Porsche on a topic like this..

neanicu

ISO 5011 Test:
The ISO 5011 Standard (formerly SAE J726) defines a precise filter test using precision measurements under controlled conditions. Temperature & humidity of the test dust and air used in the test are strictly monitored and controlled. As Arlen learned in attempting his own tests, there are many variables that can adversely affect filter test results. A small temperature change or a small change in humidity can cause the mass of a paper filter to change by several grams.

To obtain an accurate measure of filter efficiency, it's critical to know the EXACT amount of test dust being fed into the filter during the test. By following the ISO 5011 standard, a filter tested in Germany can be compared directly compared to another filter tested 5 years later in Rhode Island. The ISO 5011 filter test data for each filter is contained in two test reports; Capacity-Efficiency and Flow Restriction.

Capacity and Efficiency:
The Capacity and Efficiency test report presents the test results of feeding an initially clean filter with PTI Course Test Dust (dirt) at a constant rate and airflow. The course test dust has a specific distribution of particle sizes ranging from less than 2.5 microns to greater than 80 microns (see table below).

Every filter is initially tested at 350 CFM and the Initial Restriction or differential pressure across the filter is recorded in IN-H20 (Inches of Water). The filter is then tested by feeding test dust at a nominal rate of 9.8 grams per minute with a constant airflow of 350 CFM. The test is continued until the flow restriction exceeds the Initial Restriction + 10 IN-H20.

At this point the test is terminated and the amount of dust passed through the filter (Accumulative Gain) is measured. Dirt passing through the filter is captured in the Test Station's Post Filter. The exact amount of dirt passed is determined by measuring the before and after weight of the Post Filter.
Similarly, the amount of dirt retained by the Filter under test's “ Accumulative Capacity “ is measured by taking the difference between the before and after weights of the Filter. From these results the overall % Efficiency of the filter is calculated. This test also indicates how long a Filter will last before replacement is required (or cleaning for reusable filters).

Flow Restriction:
This report presents flow restriction of a clean filter resulting from an increasing airflow. The differential pressure restriction across the filter is reported in inches of water (IN H2O) versus Air Flow in cubic feet per minute CFM.

Data from these reports has been compiled and presented in the following bar graphs, plots and data tables.

Filtering Efficiency:
Filtering efficiency is a measure of the filter's overall ability to capture dirt.

Accumulative Capacity:

"Accumulative Capacity"� is a measure of dirt holding/loading capacity before reaching the maximum restriction limit.

Initial Restriction + 10 IN-H20.


Accumulative Gain:
"Accumulayive Gain"is the total amount of dirt that passed through the filter during the test.


Purolator was reported to have a seal malfunction during the test and passed more dirt than it would have with a good seal.)

Restriction:
Initial Restriction is the Filter under test's resistance to flow at 350 CFM.

Dirt Passed Versus Total Test Time:

This graph shows each the duration of each filter's test versus dirt passed (Accumulative Gain).

(Note: The Purolator was reported to have a seal malfunction during the test and passed more dirt than it would have with a good seal.)



In the chart above it's important to note the different test durations for each filter. The AC Delco filter test ran for 60 minutes before exceeding the restriction limit while the AMSOIL and K&N tests each ran for 20 and 24 minutes respectively before reaching max restriction.

In 60 minutes the AC Filter accumulated 574gms of dirt and passed only 0.4gms. After only 24 minutes the K&N had accumulated 221gms of dirt but passed 7.0gms.

Compared to the AC, the K&N "plugged up" nearly 3 times faster, passed 18 times more dirt and captured 37% less dirt. See the data tables for a complete summary of these comparisons.

Dust Loading:
The dust loading curves show graphically how each filter responded to a constant 9.8 gms/min dust flow before reaching the maximum restriction limit.


It's interesting to note the shape of these Dust Loading Curves. The AC and Baldwin filters each had near linear responses until reaching maximum restriction. Restriction for these filters increased at a constant rate versus the 9.8 gms/min dust feed rate.

The other filters, most notably the oiled reusable types, had an exponential loading response before reaching maximum restriction. These filters had a lower initial restriction, but they became exponentially more restrictive under a constant flow of dirt.

This runs counter to the "myth"� that oiled media filters actually "work better" as they get dirtier.

Also notice the length of the curves as it shows the relative test time for each filter (time to max restriction).

Restriction to Flow:The Restriction to Flow curves graphically show how each "clean" filter responded to a steadily increasing flow of air up to 350 CFM.

The Flow Restriction response curves for each filter have the same basic shape. However, note how the AC Filter, which passed the smallest amount of dirt and had the highest dirt capacity and efficiency, also had the highest relative restriction to flow. The less efficient filters correspondingly had less restriction to flow.


This illustrates the apparent trade-offs between optimizing a filter for dirt capturing ability and maximum airflow.