Quick question on filter sizing.

[mazur]

I'm almost done getting parts together for my S50 swap and am about to buy a filter.

I'm going with the new AEM Dryflow filter, but their 3.5'' filters only come in either 5'' or 9'' length. I would love to get the 9'' but am worried if it would fit. Any opinions?

[FredK]

Can you give dimensions on the outside diameter at the cone tip and the cone entrance?

[mazur]

Can you give dimensions on the outside diameter at the cone tip and the cone entrance?

AEM doesn't give the dimensions for that. All I know is that it's the same diameter throughout.

[matt]

5" is plenty.

[FredK]

5" is plenty.

ah, sig worthy quote.

[matt]

Hhahahahahahahahahahaha.

[mazur]

Maybe I should be asking some ladies which size is best, lol.

[FredK]

FWIW I am using a K&N RU-3130 filter with a 3.5" inlet, and a 7" length. It's a fairly thin and tall filter, with a 4.625" base and 3.5" tip. I know I could get a larger filter in there.

I am running a regular air boot stretched over a 3.5" HFM, and have the filter hooked up directly to the HFM. So, I probably have a little more room than people running an extension tube or reducer.

[mazur]

FWIW I am using a K&N RU-3130 filter with a 3.5" inlet, and a 7" length. It's a fairly thin and tall filter, with a 4.625" base and 3.5" tip. I know I could get a larger filter in there.

I am running a regular air boot stretched over a 3.5" HFM, and have the filter hooked up directly to the HFM. So, I probably have a little more room than people running an extension tube or reducer.

I'm planning on just running a filter right off the HFM.

I'd be alright with a 5'' if I knew how much it would actually flow. I want to have plenty of headroom, CFM wise, for a cammed S50.

[golde30]

my buddy has the 9" one waiting to go on his rs4, it looks HUGE. no problem with flow on that badboy.

[static]

i also run around 5" long cone Amsoil Ea filter and it seems it's enough.
Make sure to organize some kind of heatshield, i have none and in summer i can feel the power just disappears with heat.
Also i heard putting filter directly on HFM is bad as HFM wouldnt measure air properly if the air is turbulent and it is pretty turbulent at the filter exit (someone suggested having at least 4" between filter and HFM)

[matt]

i also run around 5" long cone Amsoil Ea filter and it seems it's enough.
Make sure to organize some kind of heatshield, i have none and in summer i can feel the power just disappears with heat.
Also i heard putting filter directly on HFM is bad as HFM wouldnt measure air properly if the air is turbulent and it is pretty turbulent at the filter exit (someone suggested having at least 4" between filter and HFM)

Ehhh... youre close but not quite there.

Having the filter right on the MAF is fine. If you have a bend in the pipe before the MAF, you need to have about 4" of straight pipe before the MAF after the bend. Bends will throw off your MAF readings and make your car run rich or lean. Having a bend before the MAF means you need to be careful which way you orient the MAF so it reads properly.