Air Filter Capacity

[lrp374]

I am looking @ replacing the entire air filter contraption with an open K& N unit. The K&N filter listed in WIKI that should fit is a E-4810. If my calculations are right it has a surface area of about 186 sq.". That is more than the K&N filter for my cummins diesel which is about 131 sq. ". How big a filter do I really need. I checked a typical VW diesel of about the same size and they use only about 65 sq.".

I would like to use an open filter of about 100 sq.". Is it big enough?

Larry

[Green1]

In this case, the bigger the better, larger surface area means less resistance, means more power, better efficiency, and lower temperatures.
Same idea as the larger exhaust pipes (the air coming in and the air going out are opposite ends of the same basic system)

[lrp374]

I realize that bigger is better but their comes a point when bigger is just stupid. It makes no sense to me that a 2.4 l diesel needs more filter area than a 5.9 l diesel which operates with nearly twice the boost under load. I clean my filter @ 50 000 km and have never seen the needle move on the filter gauge. I don't want to compromise on capacity but I really feel that I don't need the present filter area if the filter is in the open. Is their a chart or something that gives a typical filter area/liter of engine size or some other simple technique?

[Erebus]

Another thing to consider besides the area of the filter, is the area of the air intake hoses. You can have a 10 m2 filter, but if the housing has only a 0.1 m2 opening, then the filter is being wasted. Just something to think about.

[dennis_lambert]

"The K&N filter listed in WIKI that should fit is a E-4810"

A provided link seems to show the E-4810 filter is only good on 87 and 88 L300 ? Did Mitsusbishi change the filter can for later years? Mines a 94.......

K&N Applications for E-4810
Replacement Industrial Air Filter
Product Information and Specifications for K&N Part E-4810

2005 MITSUBISHI GALLOPER 2.5L L4 DSL - All

2004 MITSUBISHI GALLOPER 2.5L L4 DSL - All

2003 MITSUBISHI GALLOPER 2.5L L4 DSL - All

2002 MITSUBISHI GALLOPER 2.5L L4 DSL - All

2001 MITSUBISHI GALLOPER 2.5L L4 DSL - All

2000 MITSUBISHI GALLOPER 2.5L L4 DSL - All

1999 MITSUBISHI GALLOPER 2.5L L4 DSL - All

1988 MITSUBISHI L300 2.5L L4 DSL - All

1987 MITSUBISHI L300 2.5L L4 DSL - All


K&N manufactures performance air filters and air intakes for automotive & motorcycle applications around the globe.

[Green1]

Another thing to consider besides the area of the filter, is the area of the air intake hoses. You can have a 10 m2 filter, but if the housing has only a 0.1 m2 opening, then the filter is being wasted. Just something to think about.

While your point is correct, this is actually harder to calculate and isn't as simple as surface area of filter vs cross-sectional area of the hoses. Consider that the filter element offers more resistance to the air flow than the empty space of the inside of the air hose, and you will realize that you need significantly larger filter surface area than you do hose cross-sectional area. To what extent is more difficult to calculate exactly, but in general the bigger the better on both counts (I wouldn't be surprised however if your example of 10m2 compared to 0.1m2 is actually perfectly fine)

[dennis_lambert]

just curious does the air intake for the turbo also come from the stock filter can assambly?
Cheers.

[Erebus]

just curious does the air intake for the turbo also come from the stock filter can assambly?
Cheers.

The air goes through the aircleaner, down to the turbo, through the turbo, back up to the intake manifold.

[Green1]

just curious does the air intake for the turbo also come from the stock filter can assambly?
Cheers.

As Erebus said, the air ONLY goes to the turbo from the filter assembly. There is no other air intake. (This is how turbo-charged engines work)

[dennis_lambert]

I just got rid of the can assembly and installed a K and N PN# RV-1480.Its surface area is Aprox 88 Sq".It seems to work fine and fit great on the existing duct.I can notice a slight increase in power mostly in acceleration.The down side is it loud and not exactly in my opinion a cool sound.I am thinking I might try to return it and go with the E-4810 in the original can...I just wish could find confirmation on if it will fit a 94,the k and n web page shows it only fits 87-88.
Cheers.

[lrp374]

I have finally finished the first phase of the air filter experiment. I used a K&N RU-4950 filter and 2.5” tubing from the turbo to the filter. I was able to find a 2” rad hose for connection to the turbo and a 2.5” to 2” exhaust reducer made a nice transition to the flex tubing. The routing was a little tighter than I hoped but it squeezed by the rad. The connection of flex to the filter used a short piece of 2.5” pipe left over from my exhaust upgrade. The filter is small enough all the tin protection plates and my skid plate fit back as normal. I seem to get a little more air noise than before but it really makes little difference inside the van @ highway speeds. I think the EGT is reduced but I need more time to confirm it.

I don't think the flex tubing will be a good long term solution but it works great for testing. I think a more rigid install will happen in the spring.

[lrp374]

I finally completed the change from hose to all 2.5" pipe. The routing required weird bends but now it's all solid pipe.

rsz_100_3969.jpg (120.46 KiB) Viewed 7941 times

rsz_100_3972.jpg (147.43 KiB) Viewed 7942 times

[fexlboi]

Interesting and cool looking mod lrp374. Still not quite sure why.

....go with the E-4810 in the original can...I just wish could find confirmation on if it will fit a 94,the k and n web page shows it only fits 87-88.

The E-4810 fits perfect on a l300 '94

[jwfchase]

I think I can answer some of that one. I was over visiting Larry today (nice to finally meet you in person!) to look at his project. In a nutshell, moving the air intake down into the airflow under the front of the van is giving him a similar cooler air intake effect to those of you installing snorkels. It also frees up the space where the stock filter can goes for a future project he's planning... and why not just put in a snorkel? I'll let Larry answer that one...

Thanks for the photos of the completed project!

[mararmeisto]

I put a K&N on mine, but left the piping into the air plenum (instead of plumbing it forward as you have), attaching the filter there in place of the can. Even leaving it back there I noticed better 'flow' although there is an increase in engine noise without the can. I think an even better set-up would be snorkel out the side with a K&N at the top: increased water-crossing capability, better intake air flow (that can is a pretty big drag on flow), and more direct access to cooler air (out in the open instead of behind the wheelwell).