[Scott B]

Round 2 of testing is finally complete. Round 1 of testing can be found here. This test included a few more filters and was performed slightly differently from Round 1. Another variable to consider is the ambient temperature, which was a toasty 94* during today's testing. The temperature during Round 1 was much cooler (60's if memory serves correct).

Filters tested: Stock, ITG, K&N, BMC, Helene, BMS

Test Vehicle: 2008 335xi E92 6AT with JB2 and no secondary cats

Test Procedure: Each pull was done in 3rd gear. Repeated 4th gear pulls on this load-bearing dyno causes overheating even with the factory oil cooler installed and plenty of airflow in the dyno cell. RPM sampling range was from 2k to 6.8k. Boost was sampled from the BOV vacuum line, and AFR was sampled at the right-side tailpipe using an Innovate LM-1 wideband. The vehicle was warmed up to the point of the oil temp gauge being 3 hash marks short of 250* for the first run to begin for each filter. After each run, the car was allowed a few minutes of cooldown until the oil temp again read 3 hash marks short of 250*. Four runs were done on each filter. The best run for each filter is shown below compared to the stock filter (stock is the solid line). Underscoring the impact of heat, you'll see that the best run for nearly every filter (save the BMC) was the first run. The other runs, grouped by filter, are also found below. Ambient temperature remained between 91* and 94* during the entire test with humidity at 32%.

Conclusion: Under these conditions, none of the aftermarket filters outperform the stock filter.









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[shyestsparks]

Interesting.

[Global Motorsports Group]

Thank you for that info, greatly appreciated! 91 Octane?

Need more fans in that room...

[sambonator]

So filters have no effect on stock cars. It would have been interesting to see a run with no filter installed with stock airbox, to get the theoretical max possible with any filter.

Also would be interesting to see effects of various filters with a tune.

[ChaneRZ]

interesting. need a full setup air intake to gain hp.

[Leroi]

Originally Posted by sambonator

So filters have no effect on stock cars...
Also would be interesting to see effects of various filters with a tune.

Test Vehicle: 2008 335xi E92 6AT with JB2 and no secondary cats

Interesting, when compared to round 1 results.

[marcvtec]

Originally Posted by sambonator

So filters have no effect on stock cars. It would have been interesting to see a run with no filter installed with stock airbox, to get the theoretical max possible with any filter.

Also would be interesting to see effects of various filters with a tune.

He has a tune

[hotrod182]

Originally Posted by sambonator

So filters have no effect on stock cars. It would have been interesting to see a run with no filter installed with stock airbox, to get the theoretical max possible with any filter.

Also would be interesting to see effects of various filters with a tune.

Someone already tested with no filter installed and reported no increase.

[timtech]

Originally Posted by Scott B

Round 2 of testing is finally complete. Round 1 of testing can be found here.

Conclusion: Under these conditions, none of the aftermarket filters outperform the stock filter.

Very interesting results compared to Round 1. Thanks for all the time and work.

[who's ur daddy?]

What about adaptation?

Also, perhaps the better indicator is the 1/4 track instead of a dyno with fans.

But overall, I am impressed with the effort. Kudos to you for providing impartial evidence for the N54 community.

[cn555ic]

so basically from your dynos it showing that there is no effect of which brand used, the gains are nominal to the point that u can say all these companies stating gains in hp is not as great as advertised!!! Hmmmmmmm!!!!

[e90AW335i]

Originally Posted by cn555ic

so basically from your dynos it showing that there is no effect of which brand used, the gains are nominal to the point that u can say all these companies stating gains in hp is not as great as advertised!!! Hmmmmmmm!!!!

If that is the case then I am sure that would apple to UR's CAI as well.....

[Orb]

Originally Posted by Scott B

Round 2 of testing is finally complete. Round 1 of testing can be found here. This test included a few more filters and was performed slightly differently from Round 1. Another variable to consider is the ambient temperature, which was a toasty 94* during today's testing. The temperature during Round 1 was much cooler (60's if memory serves correct).

Filters tested: Stock, ITG, K&N, BMC, Helene, BMS

Test Vehicle: 2008 335xi E92 6AT with JB2 and no secondary cats

Test Procedure: Each pull was done in 3rd gear. Repeated 4th gear pulls on this load-bearing dyno causes overheating even with the factory oil cooler installed and plenty of airflow in the dyno cell. RPM sampling range was from 2k to 6.8k. Boost was sampled from the BOV vacuum line, and AFR was sampled at the right-side tailpipe using an Innovate LM-1 wideband. The vehicle was warmed up to the point of the oil temp gauge being 3 hash marks short of 250* for the first run to begin for each filter. After each run, the car was allowed a few minutes of cooldown until the oil temp again read 3 hash marks short of 250*. Four runs were done on each filter. The best run for each filter is shown below compared to the stock filter (stock is the solid line). Underscoring the impact of heat, you'll see that the best run for nearly every filter (save the BMC) was the first run. The other runs, grouped by filter, are also found below. Ambient temperature remained between 91* and 94* during the entire test with humidity at 32%.

Conclusion: Under these conditions, none of the aftermarket filters outperform the stock filter.
]

Very well done test and first here for completeness of information. I will PM you some info about correlating the previous results with this test. Given the condition I’m not surprised with the result.

PM me the info you have for ambient temperature and relative humidity of the previous test.

Orb

[DrewKo]

But the previou test you ran showed some gains over stock, so what are we to conclude?

[sambonator]

Originally Posted by Leroi

Test Vehicle: 2008 335xi E92 6AT with JB2 and no secondary cats

Interesting, when compared to round 1 results.

Why are power levels so low? I just saw the graphs and concluded it was stock. 272whp...

Originally Posted by DrewKo

But the previou test you ran showed some gains over stock, so what are we to conclude?

...that any gains from filters are statistically insignificant...?
...or that we can criticize the tester for not allowing the ECU to adapt to each filter...?

[NRG]

Very interesting info, and thanks for the time you spent collecting and testing all those filters. It looks like the BMC is still on top, even by a bit. This thread should be a sticky 100%.

[drphil71]

How many of these vendors are actually on the forum? Just Helene? BMC?

Maybe chime in?

[Bubbles]

Nice work, OP.

[kitw]

Take a look at the stock intake box. When air flows up through the filter and then across that barrier, and down to the intake horns, the cross section gets pretty small. That is going to be the largest restriction.

I just ordered some ITG cone filters, with an integrated velocity stack, that slip into the stock air intake tubes. I'll keep y'all updated when I receive them in a week or two.

[e90AW335i]

Response to the filter testing per Terry Burger@BMS:

Originally Posted by Terry Burger

Hi Scott,

It was a pleasure hanging out and helping with the test. I can definitely vouch for the consistency of the testing, and although the results are surprising I believe they are accurate.

My take on the BMS filter:

I'm not sure if it is mentioned but this testing was a lot harder than the dyno testing I've done in the past. It was performed on a Mustang load dyno, with the hood closed, in a sealed room. Airflow across the car was 30-40mph. The BMS filter tested was from my car with around 3,000 miles on it. I considered testing a brand new filter but figured a used filter would give better "real world" results. The cars were run a few times on the dyno to get them adapted and ensure everything was hot before testing started. Ambient temps were in the 90s and we used 91 octane, so these were pretty much the worst possible conditions to showcase the filter as far as heat is concerned.

But despite that this testing proved the "sucking hot air" concern is moot. Even with much less airflow than you would see on the road, it made just as much horsepower as all the drop in filters using the stock airbox. And I'm confident if we were able to turn boost up a bit that it would outperform the rest. I've done a lot of VBOX road testing and have verified the filter works on the street.

And IMHO the BMS filter was the best sounding BY FAR....

[jcarlucci1]

looks like the bms performed the best..

[fedinand]

Originally Posted by jcarlucci1

looks like the bms performed the best..

Looked like the BMC performed the best to me....