[DWR]

9 1/2 X 4 1/2 X 5 , dry air filter, #21-90035.
Fits very nicely using a 3.5 X 3, 90 degree silicone reducer (slight trimming of reducer). Approx 64% more area than similar conical air filters. Essentially the size of 2 conical air filters, side by side.

Extra air took care of a slight smoking problem I was having with the OEM filter and housing. IAT is slightly higher stopped in traffic, but otherwise it seems the same. Cold air ducting is still in place and keeps pumping outside air when on the go.

[9mmkungfu]

What kind of slight smoking were you experiencing?

[robnitro]

With the small size of the 335d filter, I wonder what's the max restriction measured?

On my x5 35d, filter minder maxes out at around 8 in h2o, and that's with a filter that's halfway dirty from what I can tell. 25in h20 is the red line warning on the gauge and that's 0.9 psi restriction.

[DWR]

Originally Posted by 9mmkungfu

What kind of slight smoking were you experiencing?

Typical diesel exhaust smoke with full throttle. In colder weather it wasn't noticeable. When the hot humid weather came it was more noticeable.

[DWR]

Originally Posted by robnitro

With the small size of the 335d filter, I wonder what's the max restriction measured?

On my x5 35d, filter minder maxes out at around 8 in h2o, and that's with a filter that's halfway dirty from what I can tell. 25in h20 is the red line warning on the gauge and that's 0.9 psi restriction.

Actually, the size of the OEM 335d filter is a little deceptive. The pleats are deep and dense. As TDIwyse showed with his air filter housing mods, the OEM filter can move a lot of air. http://www.e90post.com/forums/showthread.php?t=1179619. His mods to the air filter housing had a significant effect. Ultimately, no housing and an aftermarket filter flow the most air. I just wanted to see how much filter I could fit in the OEM location.

[Mik325tds]

Nice! Where did you get the 90degree reducer?

[Owen81]

I assume this would not fit in the ATM intake box?

[DWR]

Originally Posted by Mik325tds

Nice! Where did you get the 90degree reducer?

http://www.siliconeintakes.com/

[ChiDiddy]

Can u take a bigger picture of ur intake?

Is this correct? Filter->MAF housing->90deg 3.5" to 3.0"-> turbo?

[DWR]

Originally Posted by ChiDiddy

Can u take a bigger picture of ur intake?

Is this correct? Filter->MAF housing->90deg 3.5" to 3.0"-> turbo?

Essentially, that is correct. The 90 degree hose does need to be trimmed from both ends in order for everything to fit. I won't be near the car for over a week, so a larger pic isn't possible, at this time.

If there is interest, I suppose I could produce kits. Hit the appreciation button if you are interested.

[RL18]

Is there any room for a heat shield maybe on the backside of the filter? I think I might do this next time I change my air filter either way. Unless you decide to produce a kit. I bet the turbos sound really nice with that filter.

[fsd350]

Originally Posted by DWR

Attachment 1682635
9 1/2 X 4 1/2 X 5 , dry air filter, #21-90035.
Fits very nicely using a 3.5 X 3, 90 degree silicone reducer (slight trimming of reducer). Approx 64% more area than similar conical air filters. Essentially the size of 2 conical air filters, side by side.

Extra air took care of a slight smoking problem I was having with the OEM filter and housing. IAT is slightly higher stopped in traffic, but otherwise it seems the same. Cold air ducting is still in place and keeps pumping outside air when on the go.

DWR, Are you still using this setup? How is it doing? Thinking about the same mod for my d.

[sukutash]

Based on the pic, I don't see where the requirement for the 90 degree reducer is necessary? AM I missing something?

[Asonchadwick]

Originally Posted by sukutash

Based on the pic, I don't see where the requirement for the 90 degree reducer is necessary? AM I missing something?

I cant tell either

[RL18]

Originally Posted by sukutash

Based on the pic, I don't see where the requirement for the 90 degree reducer is necessary? AM I missing something?

I believe the reducer 3.5"x3" 90 replaces the current 90 which is 3"... because the filter will only fit inside a 3.5" opening

Edit*

Okay so I did find that the filters opening is 3.5"... but I guess I don't understand now how the 3.5"x3" reducer 90 would help since the MAF sensor goes between the 90 and air filter.

[ChiDiddy]

I did not use a 90deg hose. I just reused the stock one. Replaced the filter for airbox.

[DWR]

Originally Posted by fsd350

DWR, Are you still using this setup? How is it doing? Thinking about the same mod for my d.

Still in use. No issues other than more noise that I would prefer not to hear. I may do something about that when the weather warms up.

[fsd350]

Originally Posted by DWR

Still in use. No issues other than more noise that I would prefer not to hear. I may do something about that when the weather warms up.

Just installed the recommended filter and my slight haze under acceleration is gone also. Be nice not have as much soot on my bumper and trunk. I may clear my MAF adaptations. Did you?