new restriction gauge results

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I have to say, I a bit surprised. While checking the oil yesterday, I looked at my newly installed filter restriction gauge, which up to this point has shown no restriction what-so-ever. But its a relatively new filter so I didn't expect it to show much of anything for quite some time.

Anyway, after about 6,500 miles I was showing about 8" of water, but looks pretty clean otherwise.





I live on gravel, which is why I wanted a restriction gauge. Any ideas on when to change? Go until it shows a full 22" of restriction?

I was surprised to see some restriction at only 6,500 miles.
Thoughts?
 
My restriction gauge always reads almost time to change filter even with a new oem filter.
 
I'd probably break down and change it somewhere between 15" and 20". No real reason to do so before it hits the red 'change' band, other than maybe a little power loss. Unless this is a carbureted engine (ha!) its no longer true that fuel efficiency takes a hit with a semi-dirty air filter. The mixture isn't affected, so it just acts like you aren't quite getting full throttle.
 
Originally Posted By: BTW
What the heck is a restriction gauge???


The device pictured in the first post to indicate filter life. A filter with high restriction is at the end of its life. Without a restriction gauge you can't guess accurately the loading of the filter media.
 
25" H2O = .92 psi, so that would be ~6% loss of atmospheric pressure getting through the filter. I'd probably change it at 15" H2O.
 
Last edited:
Originally Posted By: meborder
I have to say, I a bit surprised. While checking the oil yesterday, I looked at my newly installed filter restriction gauge, which up to this point has shown no restriction what-so-ever. But its a relatively new filter so I didn't expect it to show much of anything for quite some time.

Anyway, after about 6,500 miles I was showing about 8" of water, but looks pretty clean otherwise.





I live on gravel, which is why I wanted a restriction gauge. Any ideas on when to change? Go until it shows a full 22" of restriction?

I was surprised to see some restriction at only 6,500 miles.
Thoughts?



There are two basic variations of the restriction gauge - one is like yours which measures up to 25 IN H2O, and another like mine which measures up to 10 IN H20:

FilterMinder_06OCT15_zpsih65itmg.jpg


It is my understanding that the one like yours (25 IN H2O) is designed for diesel engines while the one like mine (10 IN H2O) is designed for gasoline engines.

If your engine is a gasoline engine, then you can certainly use the restriction gauge you have, but instead of replacing the filter when the gauge indicator enters the red zone at 25 IN H2O, you should replace the filter when the gauge indicator shows 10 IN H2O (the red zone for gasoline engines).

Looks can be deceiving. I would trust the restriction gauge much more than my eyeball when it comes to filter restriction.

As your gauge is only showing 8 IN H20, I would not replace the filter yet, but keep an eye on it. Also, you might try pushing the yellow button to reset the indicator and then see if the restriction indicator immediately goes back to 8 IN H2O after normal use. When my gauge shows a restriction close to replacement values, I reset it and check again later just to be sure the indicated restriction was not a one time fluke.

HTH
 
Here's another way to go:
Do a WOT run up to redline with a new filter. In a lower gear is OK, so you don't get a speeding ticket.
That establishes a baseline.
Replace the filter when the WOT run gives twice the baseline restriction or 15", whichever is less.
The really curious can do a WOT run with no filter. Make sure the airbox is clean!
 
On a gas rig I would change it out at 15"H2o(at WOT to red line). My S2000 with a new air filter will see 8" but take the lid off the air cleaner housing(air still has to go through the air filter) and it will have none. That tells me that the stock opening to the air box is a little small for the engine. Would never had known about that without the restriction gauge.


ROD
 
Hummm.. Didn't know there were two different gauges. Good to know.

Next time I get a new vehicle ill look for the 10" unit.

15 inches might not take that long to reach. I guess ill know when I get there.

I don't ever drive hard enough to reach redline, though. Even when passing I never have to go full throttle. I think the last time I had it to the floor was when I test drove it back in December of 2013
smile.gif
 
Originally Posted By: rrounds
On a gas rig I would change it out at 15"H2o(at WOT to red line). My S2000 with a new air filter will see 8" but take the lid off the air cleaner housing(air still has to go through the air filter) and it will have none. That tells me that the stock opening to the air box is a little small for the engine. Would never had known about that without the restriction gauge.

ROD

I tried that once, the performance(0 to 60 MPH and quarter mile) didn't improve, but MPG went down more than 10-15%.
 
Originally Posted By: HTSS_TR
Originally Posted By: rrounds
On a gas rig I would change it out at 15"H2o(at WOT to red line). My S2000 with a new air filter will see 8" but take the lid off the air cleaner housing(air still has to go through the air filter) and it will have none. That tells me that the stock opening to the air box is a little small for the engine. Would never had known about that without the restriction gauge.

ROD

I tried that once, the performance(0 to 60 MPH and quarter mile) didn't improve, but MPG went down more than 10-15%.

I took the lid off to see if the restriction was the air cleaner or the air cleaner housing or something else. It was the air cleaner housing and I fixed it.

ROD
 
Where does one get one of the 10" rated gauges? I've been searching but come up with nothing. All I find is the 25" gauge.

Any chance you have a part number?
 
Originally Posted By: meborder
Where does one get one of the 10" rated gauges? I've been searching but come up with nothing. All I find is the 25" gauge.

Any chance you have a part number?


Here's one source: Filterminder on Amazon

And another source: Filterminder at Jegs

If you Google "K&N 85-2445 Filter Minder" you will find many vendors.

HTH
 
Originally Posted By: DoubleWasp
$32 for a filter minder? I get mine for free from GM trucks at the junkyard. Forget that nonsense.

You didn't pay for it ? Just remove a part from a salvage yard and walk out ?
 
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