Umm..so anyway..do you figure it's OK to use the Wix filter, even though the bypass is 8-11 psi instead of 23 psi?
Does 23psi bypass seem high?
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The only way I can see it being a REAL issue is if Audi/VW has an INCREDIBLE oil flow that would produce some INCREDIBLE PSID. Naturally, this would probably mean that your operating pressure limits would be someone above 100+PSI.
Let me give you another long and drawn out explanation. Filters can and will produce a pressure drop or elevation (depending) with just plain old flow. Now it will still be a ratio of the total flow scheme and subordinate to the engine (assuming no relief action from the oil pump) ..but it's there. So, let's say a filter is rated @ 10 PSID @10gpm using a 15Cst fluid.
..but at 10gpm of oil flow, with the same fluid ..would mean (probably - if the same oil maintains any pressure at idle) 150psi ..something very few engines are capable of .....
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Since your pressure attenuates just off idle, then you're in relief a good bit of the time. This would produce elevated PSID across the filter. This may be why they spec a very high bypass valve setting. If you went with a more common setting, you would perpetually be in bypass.
Originally Posted By: Thingfish
FWIW, the .pdf on page one is for the EJ207. That is the 8500+ rpm Non-USA 2.0 liter Impreza STi engine and not the H-6.
Even with motul 300v 0w-20 and normal oil temps I see almost 90psi at almost anything above idle.
Look closely - it's actually for the H6. Scroll down and look at the whole pdf file. Aside from the fact that is says 'H6' at the bottom of each page, there's a blow up of the engine and associated oil related parts. Definitely an H6.
FWIW, the .pdf on page one is for the EJ207. That is the 8500+ rpm Non-USA 2.0 liter Impreza STi engine and not the H-6.
Even with motul 300v 0w-20 and normal oil temps I see almost 90psi at almost anything above idle.
Look closely - it's actually for the H6. Scroll down and look at the whole pdf file. Aside from the fact that is says 'H6' at the bottom of each page, there's a blow up of the engine and associated oil related parts. Definitely an H6.
Hi,
some engine makers use very high lubrication system by-pass settings (Porsche about 130psi). This normally means a robust filter is needed and in Porsche's case the FF differential by-pass setting is around 30psi IIRC
Stick with an OEM filter is usually the best bet IMHO!
some engine makers use very high lubrication system by-pass settings (Porsche about 130psi). This normally means a robust filter is needed and in Porsche's case the FF differential by-pass setting is around 30psi IIRC
Stick with an OEM filter is usually the best bet IMHO!
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Well, Doug, although I don't have the fat nailed down on some of the newer Asian oil pumps (which appear to allow variable flow with near flat pressure output - within limits), as long as you're not in relief, there's very little differential at the filter. Now if you've got ultra high volume, then you can get static differential just from the media resistance ...but under most circumstances, you see a slight differential due to velocity changes. The engine always has the lion's share of the (near) linear series circuit (as seen across the media).
Now in a Porsche or other thoroughbred alloy, you can surely have transitions and peaks that deal with fluid inertia that can't be coped with mechanically ..or rather ..where fluid dynamics and mechanical physics are in conflict. Combined that with really high volume, you need higher peak pressures and higher bypass settings. This also mandates a reinforced media (typically mesh - sometimes on both sides).
Now in a Porsche or other thoroughbred alloy, you can surely have transitions and peaks that deal with fluid inertia that can't be coped with mechanically ..or rather ..where fluid dynamics and mechanical physics are in conflict. Combined that with really high volume, you need higher peak pressures and higher bypass settings. This also mandates a reinforced media (typically mesh - sometimes on both sides).
Hi,
Gary - The big problem is with colder temperatures, higher viscosity lubricants and higher engine revs.
These all add up to long periods of the lubrication system being in relief and quite some volumn of largely unfiltered lubricant
In one practical test on a dyno the engine (Porsche V8) was in system relief for about eight minutes - even with a great flowing lubricant
Getting the lubricant to 65C takes about 10 minutes on these engines. Some people rev them up to 4k plus when cold use 25W-50 lubricants even when the ambient temp is at freezing!
The move to higher lubricantion system pressures and higher FF system by pass requirements is largely determined by engine design factors - thank goodness for 0W and 5W cold start rated lubricants
Gary - The big problem is with colder temperatures, higher viscosity lubricants and higher engine revs.
These all add up to long periods of the lubrication system being in relief and quite some volumn of largely unfiltered lubricant
In one practical test on a dyno the engine (Porsche V8) was in system relief for about eight minutes - even with a great flowing lubricant
Getting the lubricant to 65C takes about 10 minutes on these engines. Some people rev them up to 4k plus when cold use 25W-50 lubricants even when the ambient temp is at freezing!
The move to higher lubricantion system pressures and higher FF system by pass requirements is largely determined by engine design factors - thank goodness for 0W and 5W cold start rated lubricants
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Thanks, Doug. Yes, if their hanging at limits for prolonged periods of time due to the volume/visc composite, they're going to see substantial PSID across the media.
Smart Germans.
Smart Germans.
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