This in my opinion is not applicable for our engines:
To maximize filter performance, Moroso
Oil Filters have a rating of 27 microns, which produces a maximum initial restriction of only 2.5 psi when tested to SAE j806! The result is less pressure drop, more flow, less
oil by-pass and maximum filtration performance that's so important in severe racing conditions
I ahve no idea what SAEJ806 is, maybe it is 3gpm or 30 gpm. The ENGINEERING information RP sent indicated a dp across the filter of LESS THAN 2 psig at 9GPM and 20Cst. The max flowrate a melling HV can put out is 8gpm. 15W50 at 100C has a viscosity of 20.2Cst, 10W30 is 10.7 Cst. RP micron is 99% at 25 micron and 97% at 20 micron.
Please note even the competitors filter on the RP information only had a dp of 4 psig at 9gpm. Bottom line at temp no filter is bypassing.
I think the Moroso is a good filter and mimicks the old Ford Racing FL-1HP. None of us will ever realize the benefit of a 25 micron filter over a 27 micron.
Supposed to get to 50F tonight, tomorrow morning I am going to determine the dp across the fitler with the engine
oil cold, viscosity should be about 200 Cst. If it dont bypass then it will never for us that live in Texas. Even if it bypasses no problem as long as clean side.
False and misleading advertising and my own ignorance led me to beleive that oil filter bypass all the time, so buy the best with the biggest filter. In reality for our Street engines under 15 gpm, no filters bypass at temperature and if they bypass on start-up it is only for minutes until it gets warmed up. I loath the filters FRAM with dirty side bypass valves.