shtbxr22 Posted June 9, 2012 Share Posted June 9, 2012 I have been in quite a few different vehicles with different oil pressure guages, however anytime the engine is any higher than 2k rpm, the guage seems to shoot up hard and stay around or higher than 100 psi. I have a hard time believing this as spec per subaru manual on an '11 sti for example is 14psi @ 600 RPM (6.8+ qts/min.), and at 56.8psi @ 6000 RPM (66.6+ qts/min.) Does anyone have insight in how this makes sense? Are they all inaccurate, or is there some kind of oiling magic that escapes my normal brains reasoning? p.s.-these pressures/flow rates are with oil @ 176 degrees farenheit if it matters. Link to comment Share on other sites More sharing options...
vkchu Posted June 12, 2012 Share Posted June 12, 2012 I have been in quite a few different vehicles with different oil pressure guages, however anytime the engine is any higher than 2k rpm, the guage seems to shoot up hard and stay around or higher than 100 psi. I have a hard time believing this as spec per subaru manual on an '11 sti for example is 14psi @ 600 RPM (6.8+ qts/min.), and at 56.8psi @ 6000 RPM (66.6+ qts/min.) Does anyone have insight in how this makes sense? Are they all inaccurate, or is there some kind of oiling magic that escapes my normal brains reasoning? p.s.-these pressures/flow rates are with oil @ 176 degrees farenheit if it matters. which gauges have you seen? i bought the prosport halo oil pressure gauge, but have not installed it yet. Link to comment Share on other sites More sharing options...
Mega Users paintpollz Posted June 12, 2012 Mega Users Share Posted June 12, 2012 Well with my 45 dollar prosport oil gauge, it reads 92 psi at 75-80 mph at hot highway cruise, and 24 hot idle, all day errrr day. And that seems to be standard across the board. Cold start up its pinned at 100psi, where it maxes out, so I'm guessing with cold oil its around 120 psi cold start up. my prosport boost gauge is off by almost 1 psi in the positive direction. "Remember Danny - Two wrongs don't make a right but three rights make a left." Link to comment Share on other sites More sharing options...
shtbxr22 Posted June 12, 2012 Author Share Posted June 12, 2012 which gauges have you seen? i bought the prosport halo oil pressure gauge, but have not installed it yet. the ones that I've seen are autometer, stri, prosport, and maybe a couple others. Link to comment Share on other sites More sharing options...
shtbxr22 Posted June 12, 2012 Author Share Posted June 12, 2012 Well with my 45 dollar prosport oil gauge, it reads 92 psi at 75-80 mph at hot highway cruise, and 24 hot idle, all day errrr day. And that seems to be standard across the board. Cold start up its pinned at 100psi, where it maxes out, so I'm guessing with cold oil its around 120 psi cold start up. my prosport boost gauge is off by almost 1 psi in the positive direction. which is what i've seen. I just don't understand how the "book spec" can be off by so much. Link to comment Share on other sites More sharing options...
iNVAR Posted June 13, 2012 Share Posted June 13, 2012 1) The book spec is "minimum" pressure if I'm not mistaken. 2) It doesn't say where the pressure is taken. Most gauges are hooked up to a filter sandwich adapter... that's the easiest and most common way to install the oil pressure gauge. I believe those that have tapped into the block itself through the oil galley plug get lower readings more in line with what you're saying too. 3) I have a Defi gauge hooked up via sandwich adapter and it reads like how paintpollz described, except my gauge maxes out at 140psi so I can tell you that on a cold start, it's at about 105-110 psi, not 120. Link to comment Share on other sites More sharing options...
shtbxr22 Posted June 13, 2012 Author Share Posted June 13, 2012 I dont see it as a minimum though. In the manual, these pressures/flow rates are listed as performance, not a range. Everytime ive seen a range in a subaru manual, it gives you a range. This lists specific oil temp to pressure/flow rates at two given rpms. maybe this section was a "lost in translation" item? Link to comment Share on other sites More sharing options...
I Donated thefultonhow Posted June 13, 2012 I Donated Share Posted June 13, 2012 I have the Prosport sensor with the Prosport galley plug hooked up to a VBG1 (v1.04). With Rotella T6 5w40, cold start is 75-78psi, warmed up idle is 28-30psi, and it ramps up to 72-78psi at around 2000 rpm (low end of cruising speed) and stays around there until redline. If I romp on the car hard for a while, cruising pressure goes down to high 60s, which I assume means the oil has gotten too hot. With the Wal-Mart 5w30 dino oil I'm using right now, cold start is 72-75psi, warmed up idle is 18-21psi, and cruising is 66-72psi. My guess is the oil pressure in the FSM is supposed to be measured at the sensor for the idiot light, which is probably similar to the galley plug. Link to comment Share on other sites More sharing options...
iNVAR Posted June 13, 2012 Share Posted June 13, 2012 Well there you go. ^-- Location where it's tapped makes a difference. Probably due to hydraulics and force multiplication and what not. Link to comment Share on other sites More sharing options...
shtbxr22 Posted June 15, 2012 Author Share Posted June 15, 2012 Well there you go. ^-- Location where it's tapped makes a difference. Probably due to hydraulics and force multiplication and what not. Well thank you for that. this makes the most sense to me so far. maybe they "bench test" the pumps. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.