Air Filters

[tolsen 630]

Any change from the superior original air intake, air filter, air box and ducting is likely to ruin your turbo. Just a matter of time.

[lebikerboy 96]

That's a load of tripe...

[tolsen 630]

That's a load of tripe...

I've seen some have even placed air intake inside engine compartment thereby sucking in all dust under the car. Then made it worse by fitting poor K&N or other expensive but substandard air filter.

[lebikerboy 96]

You are entitled to your opinion...

[MikeT 744]

K&N does admit more dust to the engine....

[stickman007 309]

Guess my K&N will be out the door...

http://www.nicoclub.com/archives/kn-vs-oem-filter.html

[Alex 21]

Not changing the original air intake, air filter, air box and ducting is likely to ruin your turbo. Just a matter of time.Yes, everything will wear out eventually. Just a question of how much time.I'm in agreement that a K&N will pass more dirt and lead to reduced engine (and turbo) life, but I don't think to a huge degree. I don't have one, as I'm of the opinion that the stock air filter etc can pass plenty of air, no measurable performance benefit would be seen and I already worry enough about longevity. I just don't think that a K&N, if cleaned and re-oiled regularly would have a dramatic effect on component life. Possibly on required oil change intervals, the smaller particles that a K&N is less effective on have more of an effect on oil contamination than directly on wear.Mounted in the engine compartment, drawing in far more dirt, all bets are off! That's a mod I would be very leery of.

[tolsen 630]

The K&N and ITG crowd has gone silent!

Inhaled dirt causes accelerated and irreversible wear of cylinder bores, pistons and piston rings. Dirt mixes with oil and forms a grinding paste effectively wearing down any bearing surface in your engine.

I did some simplified flow resistance tests a couple of years ago. Tested primarily the effect of delipping and modifying air intake and various used and new OEM paper filters.

Interestingly, the highest flow restriction was measured with an empty airbox, therefore no advantage fitting more free flowing filters such as K&N or ITG.

I strongly advise against delipping, convinced it is almost worse than castration of women. The main purpose of the lip is to stop water entering air intake.

The improvement by reducing diameter of cover disc (modded cover disc) was pretty small as only 0.1 kPa reduction in vacuum (0.1 kPa = 1 cm water gauge).

Difference between used paper air filters and brand new was more or less nil.

Air flow at 4000 RPM no load is comparable to air flow when making headway along a level road at 85 km/hour.

[fordnut71 1]

My smart has a k&n,came with it im 150km now with no problems. I have an explorer that has 300km an has been on 1 for years an its been oof road drag strip an can pass emissions. Just as clean as a new 1. Iv put down other cars an truck well over 300/400km for unrelated problems then the filter.Its all i use now reguardless what data says. Its like ask gm how a 57chevy can go sub 6sec in 1/4 mile.there data says it cant.

[bilgladstone 13]

I use ITG. Have for years. If there is evidence that turbo failures occur on smart engines with these filter mods with more frequency than turbo failures on OEM stock filters and intakes, I'd be interested to see it.

In addition to using the ITG filter, I have eliminated the airbox, with its sharp 90 degree elbow and corrugated intake tube. The filter is inches from the turbo's inlet. Since "the wee smartie" is due for an oil change next week, I should also take a sample for analysis.

There you go TK: silent no more, to borrow a popular phrase from our FN brothers and sisters

Bil

[turbomar 13]

I installed a K&N filter and no remap just yet and cant really say I noticed a difference in output. I might just put that Mann filter back in!

[bilgladstone 13]

Free-flow air filters in a bone stock diesel smart will make an almost nil difference. Basically, you are just exchanging a disposable filter with a washable alternative, and extending filter service intervals. Where these shine is where the intake and exhaust are suitably modified and the computer is remapped. Also, there is more to this than simple air flow. The dynamic of turbo operation and knock-on effects of gear change etc. also are affected. This is not hypothetical; I experience this in my own car, as have other smart car owners who have driven it. B

[tolsen 630]

Free-flow air filters in a bone stock diesel smart will make an almost nil difference. Basically, you are just exchanging a disposable filter with a washable alternative, and extending filter service intervals...

OEM paper filters have much longer service life and can take 4 to 5 times the dust loading of K&N:

“Accumulative Capacity” is a measure of dirt holding/loading capacity before reaching the maximum restriction limit. Initial Restriction + 10 IN-H20.

Source (complements of stickman007):

http://www.nicoclub.com/archives/kn-vs-oem-filter.html

[bilgladstone 13]

Conspicuously absent in the charts above is ITG. Their tri-foam filter becomes more efficient, filtering smaller particulates, when partially loaded, and requires much less frequent service. It also flows far more air under dust loading than cotton or paper filters. One can almost say, the dirtier, the better!

It really isn't any wonder that ITG is omitted from such filter comparisons; it easily defeats all the others.

B

[tolsen 630]

Conspicuously absent in the charts above is ITG. Their tri-foam filter becomes more efficient, filtering smaller particulates, when partially loaded, and requires much less frequent service. It also flows far more air under dust loading than cotton or paper filters. One can almost say, the dirtier, the better!

It really isn't any wonder that ITG is omitted from such filter comparisons; it easily defeats all the others.

B

The ordinate points vertically down! How can a company that does not know how to draw graphs be assumed to make decent air filters?

Perhaps you Bil can explain how to read that silly DIY graph. Kindly also advise what standard those air filter tests were carried out to. None I guess.

[bilgladstone 13]

A facile, "ad hominem" type response. I do not represent ITG, so of course cannot be expected to describe their primary research or results. Have a look on their web site and send them your engineering questions if you really want to know.

Or... just keep on using your cheap paper filters. I don't care; it's you car.

Bil

[tolsen 630]

Bil, judging by your reply I suspect you did not make much sense out of that ITG graph.

[bilgladstone 13]

TK, judging by your reply you clearly did not bother to visit the link I posted, where a more carefully drawn graph resides, and from where you may actually get answers to your demands for data if you bother to ask. This is a complete waste of electrons. Let's revisit it when there is something more deeply probative to discuss.

B

[scwmcan 0]

Attidue abounds in this thread, I think this is a somewhat touchy subject for some. For me I will keep using the OEM filters as that is what I am comfortable with, if you want to use a different filter go for it, it is your car after all. Yours seems to be doing okay Bil, and we all know that there have been turbo and engine failures with the oEM filters ( and probably with the alternatives as well). It is not worth getting upset about ( and no need for aggressive behavior from either side). It also has nothing to do with the original topic ( and sorry for sounding moderatorish, but I think this thread took a wrong turn somewhere).

Edited May 4, 2013 by scwmcan

[MikeT 744]

Split from original topic, thanks for the comment!

[turbomar 13]

Even if it's not recommended, I am seriously thinking of trimming the lip at the fresh air inlet. Sure, some water will enter the air filter housing but a couple 1/4" drain holes on the bottom takes care of that issue. Any water vapor reaching the turbo will help reduce IAT, not a bad thing!

[tolsen 630]

Air box drains without check valves will allow ingress of dirt and dust. Ingress of water may cause your filter to disintegrate and ruin your turbo. Remove outer disc cover from air intake to simulate delipping. You won't notice any performance increase because there is only a marginal reduction in flow resistance.

[MikeT 744]

Even with a decent remap, air flow is in no way a limiting factor with the power or torque!

[tolsen 630]

.... Any water vapor reaching the turbo will help reduce IAT, not a bad thing!

Could be catastrophic during periods of freezing weather. Flying ice will quickly ruin your compressor wheel.

[Coast Steve 1]

About the original posting:I think a well cleaned and oiled (very important) K and N filter would be just fine and also give you better air flow than the paper element.No it won't trap as small of micron particles that the tight weave stock paper element did, but K and N are designed to be a free flowing and safe filter for all turbo cars. I thought almost all cars got their air from under the hood or in the general area as well.An intake on the side (fresh air) will be better though.A little off topic here:On my old modified GT, I always liked a scoop on the side replacing the stock plastic puck.That brings in fresh air to the compartment and then over a washable and oil type K and N and I think I ran this set up for about 30,000kms About 10,000kms ago I added some rubber air blockers and diverters around the filter to get the clean air to the filter better.Also a much bigger washable/oil type filter with an 8" aluminum turbo bell housingThis is an "internal cone" filter and it works together with the bell shape of the aluminum to get maximum air down the pipe. The 2" silicone pipe tapers down to the stock size closer to the turbo, giving the car massive air with good speed and volume Also had a nice difference in turbo spooling, sound and for sure power.

Edited May 4, 2013 by Coast Steve