Tested the X5M Air Filter on the Flowbench

[onfireX5]

Almost gave in to mod temptation and bought a Dinan. Looks killer but they would not give me any info other than the Dinan Lid/Filters + Dinan Muffler + Dinan Stage 2 Tuning added 23 engine HP at 5000 rpm and added 14 engine HP at peak. I just wanted the dyno on Dinan Lid/Filters only. Never received it. Still love Dinan since I use their DME on the wife's 35 and it works great, but I want numbers.

So I bought a 50i air filter to destroy and took my M filter off to test. The 50i air filter has the exact same dimension at the M inlet...more on that later....a few pics..

[onfireX5]

You can see from the above pics (some turned sideways for some reason) the inlet of the 50i = M inlet. M filter has a larger filter media on the front section and it really helps airflow !

The control orifice is the oval inlet. THAT is what I wanted to test. Does not matter what you do for a filter after that point if the inlet is maxed out. So I tested the stock 50i, the M and then cut the 50i down to the inlet and flow tested the inlet....a few more pics...

[onfireX5]

(pics keep posting sideways...sorry).

On to the results:


H20 50i M CUT

1.5 137 153 180

6.0 267 312 345

12.0 381 451 487

So for a 50i, a cheap upgrade with a nice flow increase is the M Filters. If you totally REMOVE the M filter from the M Airbox, you will pick up 30-36cfm per filter (2 filters in the airbox). I see that K&N and BMC have replacement filters, but they are based on the smaller front media of the 50i filter. Will fit, but doubtful the higher flowing media will make up for the loss in filter area. The jury is still out on Dinan. If the filter is awesome, you have a chance to increase up to 30ish cfm per filter . A nice , cheaper alternative would be an aftermarket filter based on the M design. M did a GREAT job on this design. Not much left on the table. Ben, find us an aftermarket filter with the larger M front section !

[onfireX5]

BMC and K & N replacement filters. What a shame they are based on the smaller front sized 50i filter. M filter will fit a 50i box (I installed a set) and would have been the perfect base to use for both the 50i and M. Bummer.

[Yiming]

Very interesting! thanks for sharing

[onfireX5]

Thanks. I’m in a mission now to see if K&N or Green can build a filter with the M frame (on the left in the pic).

[iconoclast]

I had the BMC filters on my 50i M-Sport, now on the X5M I have the Dinan intake with tune. If I may help your research in some way please let me know.

http://f15.bimmerpost.com/forums/sho...5&postcount=34

[onfireX5]

Cool offer. Thanks. I might buy a Dinan since it should add the last 30ish cfm to the flow. I’ll put it in the flow bench if I get one. Still on the fence. A cool , stealth upgrade would be the filters only on the M frame but I have a feeling no one makes that. K&N and BMC missed the mark.

[onfireX5]

Fell off the fence and bought a Dinan to test from Ben at RGSport.

RGSport is by far my favorite BMW vendor !

Will report flow bench results Tuesday night after it arrives.

[r33_RGSport]

onfireX5 , Greatly appreciate the support for my business and the community.
Looking forward on the result.

[Jenner]

Originally Posted by onfireX5

Fell off the fence and bought a Dinan to test from Ben at RGSport.

RGSport is by far my favorite BMW vendor !

Will report flow bench results Tuesday night after it arrives.

Looking forward to your results.

I was REALLY impressed with the size of the filters compared to stock when I swapped out my intake for the Dinan. Hope your testing backs it up!

[iconoclast]

Even if the filters alone do not increase air flow substantially the engine note and the sound of the turbos spooling is worth it alone however paired with a tune it's a no-brainer and a must-have (IMO).

[Travis1807]

Originally Posted by onfireX5

Fell off the fence and bought a Dinan to test from Ben at RGSport.

RGSport is by far my favorite BMW vendor !

Will report flow bench results Tuesday night after it arrives.

Any updates??

[Jenner]

Originally Posted by Travis1807

Any updates??

http://f15.bimmerpost.com/forums/sho....php?t=1431682

http://f15.bimmerpost.com/forums/sho....php?t=1432677

[kimsta]

Nice write-up onfireX5.

So just to confirm, is it correct that the X5M air filters fit on the 50i?

[onfireX5]

Yes it will.

[r33_RGSport]

Originally Posted by kimsta

Nice write-up onfireX5.

So just to confirm, is it correct that the X5M air filters fit on the 50i?

The filter element itself will.
But, the CF cover may not.
Dinan says the S63tu engine sits lower than the N63tu.

[iconoclast]

the oem air filters should be a direct replacement and fit just fine in the n633 enclosure.

[DuSh]

Outstanding job! Am I correct assuming that on max rpms that increased airflow will yield some whp/wtq?

[onfireX5]

Yes.

[jlawphoto]

Youre a legend. Thank you for putting the work into this.

[onfireX5]

Originally Posted by jlawphoto

Youre a legend. Thank you for putting the work into this.

Thanks for the kind words. No legend, but I love this forum and the comradery here. The X5M is my favorite ride.