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What Air Filters are LS motor guys running?

FYI, in case anyone is still running a K&N, do your engine a favor and throw it away.
this 100000000000x

they suck.

they're at best only be used on show cars or at drag strip. anything else, just stick with paper air filter, or whatever OEM put in it in the first place.
 
Not looking to go cheap...but practical

and maybe racing was a bad comparison
 
I wish someone would make paper filters in the small K&N style cone form factors. Would be great for all sorts of shitboxes where you don't need performance or long service intervals but do need to keep shit out cheaply.
 
I wish someone would make paper filters in the small K&N style cone form factors. Would be great for all sorts of shitboxes where you don't need performance or long service intervals but do need to keep shit out cheaply.
or customizable universal air cleaner housing for flat panel air filters
 
I wish someone would make paper filters in the small K&N style cone form factors. Would be great for all sorts of shitboxes where you don't need performance or long service intervals but do need to keep shit out cheaply.
 
K&N's make motor builders lots of $$$$$$$$$$$$$$$

UMP's work very well they just don't flow well. I would run 2 if you are over 300HP. On a Bronco with a 427Sbf motor, we picked up 75HP going to a regular 14" filter over a single UMP. The shitty carb hat probably had quite a bit to do with that though. The high speed mixture was all over the place from the turbulence it created over the high speed bleeds.
 

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Someone asked about sizing for filters and CFM

To calculate CFM for a engine: CID x RPM x .80VE / 3456 = (?)CFM
My stock 6.0L at 5500RPM will need 465CFM
Crate race 6.2L LSX at 6600RPM redline will need 574CFM

To compare what I am running the OptiAir 1000 against the UMP Mega Super.
The OptiAir 1000 is good for just over 500CFM at 12" of restriction. 10"x15.5" housing.
The UMP Mega Super is 415CFM at 12" of restriction. 10"x17" housing.
The OptiAir 1300 is good for 1171CFM at 12" of restriction or 800CFm at 6" of restriction. 13.5"x21" housing.
The DirectFlow 1200 is good for 825CFM at 12" of restriction. 14.6"x21.1"x25.4" housing.

The OptiAir beats out the UMP per size as the filter media is thicker than the UMP filter media. Deeper pleating.

So if you are running a powerful LS, you should be running the OptiAir 1100 or 1300 or at least dual UMP Mega Supers. The DirectFlow looks to be about the same as the OptiAir with a little bit bigger footprint. The box shaped housing needs an add on precleaner where as the round filters can use the housing to cyclone preclean. The Donalson line of DirectFlow or Power Core which is similar tech comes in different shapes some flatter so that could aid in fitting them in locations.


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12" LOL.....

You want your new filter to be in the 3-4" range. 12" is ready for a cleaning or change.

Some filter houses will clean Donaldson filters up to 3 times. Dougs filter service in Escondido CA used to clean ours.
 
12" LOL.....

You want your new filter to be in the 3-4" range. 12" is ready for a cleaning or change.

Some filter houses will clean Donaldson filters up to 3 times. Dougs filter service in Escondido CA used to clean ours.
Which begs the next question related to the flow charts.

On my tiny 2.4L with shitbox vatozone air filter, I was very happy to be 23" idle and 0" WOT man vacuum.

Ate they really expecting people to accept 10"+ of manifold vacuum at wot :confused: that sounds horrible.

Size everything based on the 5" flow rate? Where should I be reading vacuum to make a real determination?
 
12" LOL.....

You want your new filter to be in the 3-4" range. 12" is ready for a cleaning or change.

Some filter houses will clean Donaldson filters up to 3 times. Dougs filter service in Escondido CA used to clean ours.

12" is a comparative number as the charts both line up. At what level you want to restrict the engine is up to you.
Since most of these large filters are designed for diesels, the charts going up to 12" is right in the middle.
Restriction gauges are a good measure of what the engine and filter are seeing
(25" H2O) is designed for diesel engines
(10" to 15" H2O) is designed for gasoline engines
K&N choose to go with 10" range and they are saying maybe around 8" you are still in the green and at 5" you are at 50%
14.696 PSI atmospheric pressure
12" of water = .43 PSI
.43/14.696 = 2.92% loss of atmospheric pressure getting through the filter, doesn't seem like all that much restriction by percentage when you figure all the other drivetrain losses

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Actual VS theoretical must also come into play if.
Campbell can support a 840HP 490CI that requires 748CFM with two 10" x 20" filters at 415CFM each or 830CFM total at 12" of restriction. Maybe the elements flow better than the Donaldson elements but it is going to be close. This is why I think a 12" design rating is a good place to start for western desert wheeling. Not that the engine will see 12" of restriction, but the filters can be sized for that number.
Some of these filter housings that can barely support a LS by the book are stupid big. 6" and 7" outlet size. I thought mine looked excessively big at 4.5" when the throttle body blade is only around 3.4"
 
Actual VS theoretical must also come into play if.
Campbell can support a 840HP 490CI that requires 748CFM with two 10" x 20" filters at 415CFM each or 830CFM total at 12" of restriction. Maybe the elements flow better than the Donaldson elements but it is going to be close. This is why I think a 12" design rating is a good place to start for western desert wheeling. Not that the engine will see 12" of restriction, but the filters can be sized for that number.
Some of these filter housings that can barely support a LS by the book are stupid big. 6" and 7" outlet size. I thought mine looked excessively big at 4.5" when the throttle body blade is only around 3.4"
Short story is “These filters should basically not be restricting power and maintaining filtering capability at the Service Interval”
 
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