I put a restriction gauge on my air filter lid. the air filter is only 3-4 months old but its sucked the gauge down into the red already. The filter has a foam wrap around it. I wonder if the foam wrap is too restrictive.
How much air filter restriction is too much?
- Thread starter chris142
- Start date
79jasper
Chickenhawk
Are you running the factory filter?
Which filter minder are you using?
Sent from my USCC-C6721 using Tapatalk
Which filter minder are you using?
Sent from my USCC-C6721 using Tapatalk
79jasper
Chickenhawk
Maybe it needs cleaned.
But what filter minder are you using?
Sent from my USCC-C6721 using Tapatalk
But what filter minder are you using?
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CDX825
filtration nut
According to my International engine manual 25" H2O is the maximum allowable restriction for our engines.
That's generally in the red for most diesel air filter minders.
That's generally in the red for most diesel air filter minders.
PwrSmoke
Full Access Member
Restriction gauges come calibrated to different levels. Those intended for gassers usually only read to a max of 15 or 20 inches of water. Diesels often go to 25 or 30. Which gauge do you have? Brand and to what max calibration? Another thing that makes a difference is where the gauge is installed, so that could be a useful fact to relate as well.
I have also seen 25" listed as the max restriction for the 6.9L but I've never seen any readings on the stock NA trucks. I installed one on my 6.9 with the Banks Gen 1 turbo kit and with the K&N filter that is a part of the kit, it makes 15" at WOT (about 14 psi max boost) with the filter perfectly clean. I doubt a new fitler will have excessive restriction but we will know more once you relate some numbers.
I have also seen 25" listed as the max restriction for the 6.9L but I've never seen any readings on the stock NA trucks. I installed one on my 6.9 with the Banks Gen 1 turbo kit and with the K&N filter that is a part of the kit, it makes 15" at WOT (about 14 psi max boost) with the filter perfectly clean. I doubt a new fitler will have excessive restriction but we will know more once you relate some numbers.
The restriction gauge came from Fleabay. I tossed the box already but it was an IHC part. it does not have numbers. Just Red and Green colors. I was able to screw it right onto the spot on my air filter lid with just a little persuasion.
I was afraid that I was tossing my air filters too soon but Now I don't think so. I just checked the 4 month old filter and it and the wrap were very dirty. I washed the foam wrap and it had lots of black dirt in it. Tapping the filter got a bunch of dirt out of it. I find it hard to believe that I just get 4 months of use out of my air filters.
I was afraid that I was tossing my air filters too soon but Now I don't think so. I just checked the 4 month old filter and it and the wrap were very dirty. I washed the foam wrap and it had lots of black dirt in it. Tapping the filter got a bunch of dirt out of it. I find it hard to believe that I just get 4 months of use out of my air filters.
vpcatfish
Registered User
most diesels max is 25 in-h2o most restriction gauges / Donaldson gauge read a max of 30in-h2o. naturally aspirated or charged air system will not change that because at 25-30 in-h2o is when it starts to draw air from other places like the gasket on the air filter and the air filter housing causing the engine to get dirty/unfiltered air. personally the money spent on air filters is a small cost to keep the engine from getting dirty air. i know that when driving around the dirt roads and towing hay i go through one air filter about every 2 to 3 months so 4 months is not unheard of.
PwrSmoke
Full Access Member
Well, there's yer trouble. It's probably calibrated for a gas engine or a diesel that normally has low restriction, or much less restriction than your truck. The three-color-only gauges are often calibrated for a particular engine or type of engine. Obviously not a 6.9L Ford. If it trips with a new filter, it obviously not calibrated for anything remotely like your truck.
Hey Chris: If you have a hand vacuum pump with a gauge you can get an idea on how much restriction you have. Connect the hand pump to the restriction gauge with an adapter and slowly pump it up taking note of the vacuum required to trip the gauge to red. A restriction gauge is nothing but a recording vacuum gauge.
I suggest you look for a gauge with a range of 10-30" or 8-20"and then change the filter at 20" ... or 25" at most. The diesel manuals usually say that you change the filter at 20" for max fuel economy but up to 25 is OK if you want to eke the max life out of the filter. Some HD trucks with robust fitlers can take 30" but in every case I've checked, they weren't light trucks, which don't have filters that are as robust.
Remember that the air fitler works best after it gets dirty. A useful stat I got from an engineer at Parker is that an air filter will pass 90% of the lifetime amount of dirt in the first 10% of operation. The efficiency of an air fitler often improves 2-4% in it's operational life, much of that in the first 25% of life. If you wonder how much dirt that is, here are some more stats:
Code:
For Every 10 Pounds of Dust Drawn Into the Air Filter Inlet:
EFFICIENCY OF FILTER DUST INTO ENGINE
99.95% 0.005 lbs.
99% 0.10 lbs.
95% 0.50 lbs.
90% 1.0 lbs.The average filter starts out at 96% so if it goes up three percent, look how much less dirt is getting into the engine.
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