Air Filter Shootout Test - Results!
 

First off, I want to thank MitsuStyle for purchasing the delicious White Castle we had for lunch and Modern Automotive Performance for donating the 3 hours of dyno time needed to complete this test. The test was performed on a AWD DynoJet. Peak boost was 29.0 plus/minus .5 psi for each filter. This test takes into account only power produced and in no way tested filtering ability.

CAR USED FOR TESTING

2005 Mitsubishi Evolution VIII GSR SSL
Evo IX turbo w/ported exhaust housing
E85 fuel (winter blend = 70% ethanol)
Buschur TBE w/testpipe
Buschur ported/coated exhaust manifold
Buschur coated SS o2 housing
Buschur Deluxe FMIC with Buschur LICP/UICP
Kelford 272 cams w/ GSC beehive springs
Evo IX BOV
Buschur intake pipe
Buschur ported IM/65mmTB
FIC 1050cc injectors
Walbro 255HP fuel pump
Buschur old air filter (dry, no longer available)
Tune with MAF scaling set for the Buschur filter

FILTERS TESTED

Buschur (old style, no longer available, old and rusty)
http://www.scheides.com/albums/evo-a...9429.sized.jpg

Perrin
http://www.scheides.com/albums/evo-a...9437.sized.jpg

Amsoil
http://www.scheides.com/albums/evo-a...9435.sized.jpg

Vibrant
http://www.scheides.com/albums/evo-a...9433.sized.jpg

K&N - FIPK
http://www.scheides.com/albums/evo-a...9432.sized.jpg

Apexi (note small filter inlet in 2nd picture)
http://www.scheides.com/albums/evo-a...9430.sized.jpg
http://www.scheides.com/albums/evo-a...9431.sized.jpg

K&N - small
http://www.scheides.com/albums/evo-a...9436.sized.jpg

no filter
http://www.scheides.com/albums/evo-a...9438.sized.jpg


RESULTS

Buschur: 378whp/361wtq (old style, no longer available)
Perrin: 376whp/345wtq
Amsoil: 374whp/344wtq
Vibrant: 371whp/351wtq (current style Buschur air filter)
K&N - FIPK: 369whp/355whp (comes with Typhoon intake kit)
Apexi: 367whp/357wtq
K&N - small: 367whp/346wtq (caused more knock than others)
no filter: 375whp/358wtq (not recommended to run filterless!)

http://www.dsmstyle.com/photopost/da...FilterTest.jpg


CONCLUSION
The car's tune was properly setup and scaled for the old-style Buschur air filter so take those results with a grain of salt. Excluding the Buschur, the Perrin filter showed the highest peak whp which was ~10whp higher than the K&N's which CBRD noted a few months ago (thats the thread that spurred the idea for this filter test). The Amsoil filter was very close on Perrin's heels and considering their claims of being the best filtering air filter and very minimal maintenance (no oil, just blow out with air compressor to clean) it may be a very good choice for a street car. K&N's performance in this test was extremely disappointing especially since that is all they do! Apexi makes a good filter but the small inlet really hurt it in the test; this is their Evo kit and MAF adaptor and its really odd to me that they wouldn't use a filter with a larger flange. The runs without an air filter really go to show that at this power level a good performance air filter poses very little restriction. It is also interesting to note that the owner of this car, Scheides, has already ordered a Perrin air filter and Vibrant MAF adaptor to replace his old rusty Buschur air filter with. I will most likely be running a Perrin on my car, but I am still considering the Amsoil due to its filtering ability. I personally run a Vibrant on my car right now and the inside of my MAS is very dirty leading me to believe it does a very poor job filtering the incoming air.

Pardon the salt and dirt every where; its the middle if winter here in Minnesota and is impossible to keep anything clean.

http://www.scheides.com/albums/evo-a...9443.sized.jpg

http://www.scheides.com/albums/evo-a...9427.sized.jpg

MAP shop car (white VIII RS) & Scheides' car afterwards for lunch
http://www.scheides.com/albums/evo-a...9444.sized.jpg

-Chris Hughes

Taken from my old thread; please note the red generic filters would not fit my adapters so they could not be tested.

Here are a few quick pictures and initial impressions of some of the filters:

http://www.mitsustyle.com/photopost/...m/IMGP1264.JPG
Perrin - generic - Amsoil - Vibrant

http://www.mitsustyle.com/photopost/...m/IMGP1265.JPG
Perrin: Oiled foam type filter, massive surface area, came drenched in oil so I rubbed some of it off with paper towels, can't see daylight through filter.

http://www.mitsustyle.com/photopost/...m/IMGP1266.JPG
generic cone: cotton gauze oiled filter, open top for more filtering area, looks to be very high in quality, can't see much daylight through filter leading me to believe it will filter decently, possible flange leakage as its not molded directly to the filter base.

http://www.mitsustyle.com/photopost/...m/IMGP1267.JPG
Amsoil: Dry filter, easy cleaning with only an air compressor, extremely high quality in appearance, the best filtering air filter available according to Amsoil, open top with plastic internal velocity cone, I'm the most impressed with this filter.

http://www.mitsustyle.com/photopost/...m/IMGP1268.JPG
Vibrant: Dry filter, good quality, open top for extra surface area, can practically see through the filter so I'm guessing this does nothing but keep bugs and birds out of your turbo.

http://www.mitsustyle.com/photopost/...m/IMGP1270.JPG
K&N: The excess black rubber on the filtering media (oiled gauze cotton) really disturbs me, this does nothing but cut into the available surface area for filtering/airflow, is between the Vibrant and the generic filter in terms of light that can be seen through it, based on appearance only the K&N is the worst quality.

Do you have logs of the tests, specifically baro?

Since the baro sensor is in the MAF, it's very easy to see which filter is the least restrictive by looking at the drop in baro measured at the MAF. The less drop, the less restrictive.

Woot! What a blast! Tons and tons of dyno pulls and the car is running like a champ. It was a good time and I'm glad we finally put this test together. It was amazing to see how all the different filters performed by just swapping them out. I have logs from each and every pull we made today. AFR's were very consistent from filter to filter, and the only real curve ball was doing no filter at all; which made no more power than the higher performers. I'm glad to see my old rusty buschur filter holding up and performing like a champ; it's too bad the newer ones they are pimping do not perform the same as the old ones.

All in all I'm sure we'll keep adding info to this thread as time goes on. Please keep flaming to a minimum, we did what we could with what we had. Please take this test at face value. We have no hidden agenda or anything to gain from posting these results; just did it for fun! And of course, for the most powerful cars on the street ;)

-scheides
owner, MitsuStyle.com

ps--special thanks to Modern Automotive Performance for donating the dyno time. If you're interested in any of the products featured here, contact them!

Great testing man, thanks for the results.

I wonder if anyone will ever test performance and filtering though. The Perrin is the same material as the HKS which has been known to perform well but filter terribly. The Perrin also requires the oil for filtering opposed to the others that don't, so I guess by removing most of the oil you sacrifice filtering for performance.

None the less, great job!

interesting{thumbup}{thumbup}{thumbup}:mitsu:

We saved the logs from all the runs; I will ask Scheides' (since we used his laptop) if he logged that parameter and if so we'll post it.

Coolant temp and air temp (at MAS) were all within the same normal operating range so those should not have effected the results at all.

Thanks for finally doing this!

I'm sure many people on EvoM will be very appreciative that you've done so!

Think I'll be ordering a Perrin as I dont DD my car anymore anyways. Thanks for the test great work. {thumbup}

Thanks, I would appreciate it. The only reason I ask is because power numbers can be slightly different from filter to filter due to the maf readings being slightly altered from filter to filter. This would cause different load values and different timing/fueling cells to be hit.

The baro measurment is pretty straightforward though and shows the restriction of the filter.


Thanks

Interesting how the K&N and Apexi have about 7-10 less hp than the perrin & Amsoil but around 10ft-lbs more tq than the Perrin and Amsoil.

Also, special thanks to OilDoc for supplying the Amsoil air filter and evoredy for donating the K&N air filters used! I'll also give a special no-thanks to Perrin for telling me they'd donate a filter but never actually sending one so I ended up buying one myself through MAP (thank you MAP!) ;)

Scheides - Thanks for donating your car for the testing!
Zac - Thanks for supplying the Apexi filter and MAF adaptor!
Shawn - Thanks for supplying the K&N FIPK MAF adaptor!

i wish you tested the HKS RS filter. imho it would have done well. nice results thanks

I believe the Perrin foam is tighter cell than HKS which would give it better filtering properties. I believe the Perrin is manufactuered by UNI and UNI foam air filters are used on motorcycles and off-road ATV's; if that stuff can survive in the dust and mud i would think it could handle the streets. This is all speculation though so don't take my word as truth here; just my personal opinion :) Also, please note that the new HKS foam filters are dry and not oiled. I did not remove all the oil from the Perrin filter either, I only wiped away the excess on the surface.

Thanks for letting us be a part of this guys! Now it's time for my shameless plug ;)