[Jason4486]

I have done some research and cant seem to find the positive vs. negative aspects of one over the other. I know that the oiled air intake will allow for more air flow but I feel like I am not getting the whole picture. Any input is appreciated.

P.S.
I have a N55 so would adding an aFe/HP air filter to the new Afe air intake for the N55 actually add any power? Sorry if this is a no brainer. Im a newb when it comes to intakes

[Ghines1279]

oiled filters the air better, but can foul up Sensors if its oiled to heavy. I have an N54, but principles are the same, More filter surface area = more air = more power. A turbo will suck in alot of air compared to N/A. there is still a big debate about whether a cold air makes a difference. The air goes right to a 300-400 degree turbo, A 20 degree drop in air temps hitting a 400 degree turbo doesn't matter, especially after it goes through an intercooler.

[tscdennab]

Originally Posted by Ghines1279

There is still a big debate about whether a cold air makes a difference. The air goes right to a 300-400 degree turbo, A 20 degree drop in air temps hitting a 400 degree turbo doesn't matter, especially after it goes through an intercooler.

The debate is only maintained by cheap intake manufacturers and lack of ideas. Install a cold air intake in your car and you will feel the difference right away.

[Jason4486]

I read that oiled cold air intakes require some maintanence. How often should it be re-oiled? Is it easy to over oil the intake? Should I have a mechanic to it or is it something I could take care of myself? Sorry for so many questions, I am just excited about finally adding some power to my car as I have ruled out tuning the N55. I value my warranty to much to take any chances.

[WinoGregorio]

Cold air is denser. A 20F drop could theoretically net 3.5% HP increase. MANY factors involved but the ideal gas law formula PV=nRT applies here. Take for example at sea level 500cf air at 150F contains 509 moles. At 130 it contains 527. 509/527 is about 3.5% greater density and the computer will be able to take advantage of that.

Unless the paper filter is very restrictive, the cold air intake will be money better spent.

[Jason4486]

so Im guessing from your post that a paper filter is the dry filter which provides less HP?

Are all cold air intakes oiled then?

Originally Posted by WinoGregorio

Cold air is denser. A 20F drop could theoretically net 3.5% HP increase. MANY factors involved but the ideal gas law formula PV=nRT applies here. Take for example at sea level 500cf air at 150F contains 509 moles. At 130 it contains 527. 509/527 is about 3.5% greater density and the computer will be able to take advantage of that.

Unless the paper filter is very restrictive, the cold air intake will be money better spent.

[tscdennab]

Originally Posted by Jason4486

I read that oiled cold air intakes require some maintanence. How often should it be re-oiled? Is it easy to over oil the intake? Should I have a mechanic to it or is it something I could take care of myself? Sorry for so many questions, I am just excited about finally adding some power to my car as I have ruled out tuning the N55. I value my warranty to much to take any chances.

K&N recommends re-oiling every 50000 miles, but most re-oil every 5000-10000 miles. The re-oiling process is very easy and a K&N re-oiling kit costs about $15.

Dry filters get dirty and lose their high flow capacity faster, I would recommend oiled, they are tried and proven.

[Jason4486]

Thanks for the tip.

Originally Posted by tscdennab

K&N recommends re-oiling every 50000 miles, but most re-oil every 5000-10000 miles. The re-oiling process is very easy and a K&N re-oiling kit costs about $15.

Dry filters get dirty and lose their high flow capacity faster, I would recommend oiled, they are tried and proven.

[WinoGregorio]

Originally Posted by Jason4486

so Im guessing from your post that a paper filter is the dry filter which provides less HP?

Are all cold air intakes oiled then?

More often than not, CAIs include oiled filters because most paper filters are pretty restrictive in the upper RPM ranges. This is where the biggest gains can be had and putting in a paper filter would negate some of them.

I'd love to see some real flow bench and dyno data comparing paper and oiled filters in both clean and dirty situation on this model.

[I335]

I struggled with this question too before I got my AFE oiled intake. Not so much because I didn't understand the difference, but because I didn't understand the maintenance. If you search on You-Tube you can easily find videos on "how to recharge an AFE filter" for example. Once I saw a couple videos I realized how easy an oiled filter is to clean and recharge. Also, don't forget that even the dry filters need to be cleaned just like the oiled filters so you're not saving much from a maintenance perspective.

Cleaning the filter is the bulk of the work (although not difficult at all); oiling them is easy, especially if you get it in aerosol form. It can easily be done in under an hour, but then you'll need a few more hours (I think the recommendation is 3 hours) to let the filters "sit" so the oil can spread throughout the element - and it spreads quite a bit. I wouldn't worry about over-oiling, as long as you have a little common sense and follow the instructions you'll be fine. The oil is dyed (typically blue or red) so you can easily see if you missed any spots which you take care of with a drop here & there after the filters have been sitting a while. If you can make a cup of coffee, you definitely don't need a mechanic to do it for you. Good luck...

[Jason4486]

So your saying that I will/should know when to re-oil the filter?

Or are you saying that an air intake is a bad idea in general?

Originally Posted by maxnix

Just look at any intake path running the OEM paper filter for 10K miles or more.

If you think putting additional oil in the intake path is still a good idea, then do it.

[boom]

That's actually not true. Typically a turbo will heat the air by a specific amount depending on thenconditions and boost/efficiency of the turbo, etc. Likewise an intercooler will cool the charge by a repeatable ambling depending on the charge air temp and ambient temp. Whatever combination you have will result in a net increase of the air temp and this will not change that much, e.g. Ambient temp=70 deg, iat=120; ambient temp=50 deg, iat=100; ambient temp=110, iat=160; etc. The delta doesn't change much. The initial air temp matters a great deal.

Originally Posted by Ghines1279

oiled filters the air better, but can foul up Sensors if its oiled to heavy. I have an N54, but principles are the same, More filter surface area = more air = more power. A turbo will suck in alot of air compared to N/A. there is still a big debate about whether a cold air makes a difference. The air goes right to a 300-400 degree turbo, A 20 degree drop in air temps hitting a 400 degree turbo doesn't matter, especially after it goes through an intercooler.