Yup, agree with everything above.
I think the normal Wix (non XP) is a better option if you go by the literature that the manufacturer has supplied.
The Ryco ST filters available here are 99.8% @ 25µ and 98.7% @ 16µ, so i'll probably go to those once I've burned through my mountain of oil filter's i've got here.
https://www.rycofilters.com.au/catal...ndex/part/Z9ST

 

Looking forward to see what you find

 

Just a dum question for the experts on this thread, I run high oil pressure cause my squirters and balancers have been deleted, I am talking 100psi on cold start up so is there any chance that my oil filter is being bipassed all the time due to high pressure?

Also what change in oil pressure does using 15w 50 oil make over 0w 40?

 

There is a chance, more info to come on that.
A thicker oil will make your problem worse.
If you're running 0W40 now and dont have any low oil pressure problems when hot, then I wouldn't go thicker (IMO).

 

I don't believe there will be any surprises, but we shall see. When I ran a bypass vs non-bypass I saw no difference in oil pressure based on the gauge readings, but that is not the same as a datalog. If we assume the ID of the oil pump outlet is 0.5" then that is a surface area of 0.785 in2. If we look at the surface area of the standard OEM filter based on your data, it is ~107 in2. The reason there is minimal pressure loss is that you have increased the flow area by (107/0.785) 136x and I suspect most of the 3psi of pressure loss was due to how the oil has to flow through the housing itself and has nothing to do with the filter element. The fact that the pressure differential was not effected when you almost tripled the surface area indicates the flow through the housing itself is accounting for a large portion of the pressure drop.

 

Before you go to too much trouble I think I did misinterpret your data. You do see resistance increase between the two logs you posted for the wix. I dunno, I guess I was reading it like a dyno sweep and not as just constant rpm samples. Anyway the pressure drop in your high rpm sample is 12.8 which seems much more in line with the spec of the bypass valve. So the 3psi log is likely bypass closed. Sorry for the noise. Thanks for putting in the work on testing these.


I don't know if your interested in doing more testing, but I would be interested to know at what RPM the different filters basically hit their bypass. I think that would give a good indication of how much the filters can flow compared to each other.

 

Oil flow through the engine doesn't increase with RPM after a certain point.
The amount of "leakage" that an engine has (past bearings, oil squirters etc) is a set orifice size. This only changes with oil temp and oil viscosity.
Oil pump flow does increase, but that's mostly bypassed. Especially on the 4G63 platform.

The only way you could see what you're asking is if you change the oil pressure regulation system to after the oil filter. From OEM it's before the oil filter.
There is no real benefit in pushing all of the oil through the oil filter, even if it doesn't make it to the engine.

 

The speed of the engine also effects how much oil it needs too though right? If flow doesn't increase with demand wouldn't pressure drop?

 

I've always been interested in this but haven't done much to dig into it.

On my 4B11T, it def drops pressure and then stabilizes after 8,000 rpm at WOT. I always wondered what is causing that.

BTW, this is with a Royal Purple 10-2808 filter and 20w-50 VR1 oil.

 

Yep, the oil passages after the oil pump are a set restriction, "set orifice size," so the only way for oil flow through the engine to increase is to lower the oil viscosity and/or raise the oil pressure. There are some things like the oil cooler thermostat or a TurboSmart oil pressure regulator that can change the "restriction" at a certain temperature or pressure, but for the sake of argument it doesn't change. The oil pump will absolutely flow more as the RPM increases, but the oil pressure regulator will dump (bypass) all excess oil back to the pan once that bypass pressure is reached and before it reaches the oil filter. As you pointed out, the oil filter never experiences the full flow potential of the oil pump because the oil bypass occurs before the filter.

Nice work and your graph designates the filter as an XP, but pics show it as non XP.

 

Good to see someone is paying attention

 

Ok.
Lets break this down.
The oil pressure regulator has reached a set height (dump hole size) by that point.
So any oil pressure decrease must be after the oil pressure regulator.
So something in the oiling circuit after the oil pressure regulator is causing a slightly drop in pressure.
Oil filter? Oil Cooler? Oil Squirters? MIVEC?
Where is your oil pressure measured?

 

I don't think it matters what the pressure is at the input of the oil filter for the purposes of what I am asking. What I care about is what the pressure drop is across the oil filter. What my thinking is you will see the pressure drop increase as flow increases. You see this in your captures.... there is more pressure drop across the filter at the higher rpm's than at the lower. If the oil was at OT at low RPM there would probably be even less pressure drop there. So what I would expect to see is pressure drop increase until it hits the filter bypass spring pressure and then pressure drop should plateau. If the drop never plateaus or reaches bypass spring pressure then I would assume that indicates it never goes into bypass.

I think this is analogous to testing the resistance of a component in circuit by observing voltage drop as you increase current. In this type of test it doesn't matter what the input voltage is, so long as you are measuring against it.
What do you think, am I incorrect in the way I am approaching this? Of course this assumes flow (not pressure) will actually continue to increase with higher engine RPM. That might be the flaw in my whole approach here. I am making that assumption based on what I assume is non-static oil consumption like the crankshaft (moving oil passages).

 

Yes - but I think it is much less than you think with a new filter. It will be like pushing 10amps through a 4 gauge wire. Sure there is a restriction, but it's very small.
It's not like pushing 10amps through a 22 gauge wire.

There really isn't. It's about the same.

yup agreed. But with a new filter, it would appear that the media element in the oil filter presents a *near zero* restriction.
The pressure drop between the inlet and outlet is more to do with the change of oil flow direction than the actual media itself.
*Note - obviously this will change when the filter starts to capture dirt/grit and starts to become blocked. This will change the PSID across the element and this is the benefit of having a larger filter media surface area.


Oil flow through the filter will likely be similar to the pressure scatter graph.
It's getting 80% of the flow at 3000rpm, then there is a small flow increase towards 7500rpm.
But the oil flow through the engine isn't linear with engine rpm.
Flow through the engine will increase with a thinner oil (lower weight or higher temp).

If the oil pressure and oil temperature is constant at a bearing, then the oil flow through that bearing clearance will remain constant regardless of RPM.

As an educated guess - the OEM oil pump flows around 2.5GPM (9.5LPM) for every 1000rpm, assuming no drop in efficiency at higher flow rates.
At 7000 rpm that is around 17GPM (67LPM).
On my setup the oil pressure regulator cracks open at around 3000rpm and flattens off at around 6000rpm.
My assumption is around half of the engine oil pump flow gets dumped by the regulator at higher rpm's.

 

I really appreciate you taking the time to engage with me on this. Hopefully your forehead isn't too bruised from all the facepalming . A very long time ago someone "explained" to me how these oil filters work, someone I have a lot of trust in. Your tests here and all the effort you have put in explaining have really made me rethink all that though. Maybe he wasn't wrong, and I just misunderstood what he was saying, or the context. I'm really glad we still have folks like you in the community willing to put in the effort and share.

That is weird, do you know if it's at all common to the 4b11? I'm not setup to do oil pressure logging on my X, otherwise I'd go see for myself.