Originally Posted By: ZeeOSix
Originally Posted By: Scargo
Now, I have a new 430 AWDHP DAVCS engine with a 12mm pump and a Peterson external pressure relief valve and the same K&N oil filter. The 12mm pump is capable of more pressure (85 vs 43) but is rated at 6% less flow than the 11mm pump @5,000 RPM, but I will be taking it to 7,500. The engine is a few tenths looser on the rods and mains. It just came off the dyno. 85 PSI+ is no problem.
Should I consider looking for a higher bypass pressure filter? There is a fairly large K&N HP-2005, where the bypass is rated at 27-35 PSID.
I thought most Subarus had really high volume output oil pumps with a high pressure relief setting (way higher than 43 PSI) as mentioned many times in this thread. That was the main theory why Subaru oil filters had such a high bypass valve setting - the high oil flow through the filter will cause more delta-p and therefore should have a higher bypass setting.
Many will run an additional shim on the 11mm pump if the motor is going to see race duty. This is with stock bearing clearances. I have a huge Setrab oil cooler and nine quart capacity when the Accusump is included. I've never had overheating conditions with water or oil (in past engine).
Engine oil pressure corresponds to the effort required by the pump to put the pump's output volume through the engine's oiling system. Seems like if the new 12 mm pump puts out less flow volume at 5,000 RPM, and your bearings are setup with a looser tolerance, then the observed pressure should be less at 5,000 RPM (compared to the old 11 mm pump) if running the same oil at the same temperatures. I'm assuming you've bumped up the new pump's pressure relief setting to allow more max pressure, which should mean more oil flow to the engine at higher PRM due to higher pump relief.
The 12mm pump seems like it should be capable of more volume but is listed as making more pressure than an 11MM pump. However, I ported the pump and the galleys and will be revving the engine to 7,500 RPM. The Peterson valve seems to be doing a good job of controlling the pressure. I just have a little more clearance on the bearings beyond stock. 525-550 hP is not an outrageous amount of power. It is all well-balanced, too.
Originally Posted By: Scargo
The thing is that I've had no oiling issues. While I've ran this motor two of my track buddies with STi's have thrown rods through their cases. They ran stock sized filters in the stock (very hot) location. No oil coolers. Both were in the 370 AWD HP range.
Any ideas what oil filter brand(s) they ran? With no oil coolers, they probably threw a rod because the the oil thinned out way too much and caused bearing metal-to-metal contact and eventually bearing lock-up and rod failure.
Originally Posted By: Scargo
I know this is pretty anecdotal but my setup works for me. You would think that I would have more oil bypassing and more and bearing wear.
It's been mentioned may times that the bypass setting of oil filters has a lot to do with the filter's flow resistance, and the expected max debris loading and max expected oil flow. As mentioned already, many believe the Subaru filter bypass is set high because of the unusually high pump volume, and who knows how restrictive the filter itself may be as part of the equation - could be part of the reason their bypass is set high. Subaru may also set their bypass really high just to ensure the filter hardly ever bypasses in the most extreme use conditions, similar to what's done with "racing filters".
My goal is to run 5-30 oil.
BTW, Fram has a new racing filter with metal end caps and a high bypass valve setting (in the 20s), high flow specs with most likely a better efficiency than the K&N ... might be another filter to consider also.
https://bobistheoilguy.com/forums/ubbthr...eas#Post4263567