Oil Pressure.. too low?

[xwd]

8mm.

I installed my gauge and oil pressure/temp sensors this weekend. I removed the factory oil light switch and put the pressure sender in there, and used the galley plug on top of the block for the temp sensor. Thankfully it was like other Subarus and unplugging/removing the pressure switch does not cause the light to come on.

I'm getting roughly the same values you saw above. Once the car is warmed up I'm at about 150kPa at idle and when I get on it up to about 750kPa.

The oil temp probe on top of the block consistently reads 10-15c lower than stock gauge, as via OBD2/Torque. Driving to work the max I saw in Torque was about 95c and on the gauge about 80c. Not sure if it's the location or differences in the thermocouple... So I set the warning to like 110c.

[Dave-ROR]

Originally Posted by dwx

8mm.

I installed my gauge and oil pressure/temp sensors this weekend. I removed the factory oil light switch and put the pressure sender in there, and used the galley plug on top of the block for the temp sensor. Thankfully it was like other Subarus and unplugging/removing the pressure switch does not cause the light to come on.

I'm getting roughly the same values you saw above. Once the car is warmed up I'm at about 150kPa at idle and when I get on it up to about 750kPa.

The oil temp probe on top of the block consistently reads 10-15c lower than stock gauge, as via OBD2/Torque. Driving to work the max I saw in Torque was about 95c and on the gauge about 80c. Not sure if it's the location or differences in the thermocouple... So I set the warning to like 110c.

I want to log mine to see what the OEM gauge sends but I don't have a fancy OBD2 dongle thing.

[brillo]

wanted to resurect this thread as I'm not clear if running 0W-20 with a 13 row oil cooler (I know Dave-ROR has a larger 19 row unit) at high temps and high RPMs results in oil pressure that is too low or not. It appears from the observations above running 0W-20 with a cooler for daily driving is not the issue.

I'm going to be hitting the track in November (cooler weather by Houston standards) and I'm trying to understand if I need to switch my Amsoil 0W-20 to 0W-30 before I do that given I have a oil cooler kit.

Many thanks.

[robispec]

We run 5w30 with zero issues. But we also keep the cars temps in the low 200s.. 10k racing miles...

[xwd]

Originally Posted by brillo

wanted to resurect this thread as I'm not clear if running 0W-20 with a 13 row oil cooler (I know Dave-ROR has a larger 19 row unit) at high temps and high RPMs results in oil pressure that is too low or not. It appears from the observations above running 0W-20 with a cooler for daily driving is not the issue.

I'm going to be hitting the track in November (cooler weather by Houston standards) and I'm trying to understand if I need to switch my Amsoil 0W-20 to 0W-30 before I do that given I have a oil cooler kit.

Many thanks.

I got your PM. I am not running an oil cooler, and for now am just autocrossing the car and haven't done any track days. That being said, I still run 0w-30, I'm not a huge fan of running the stock 0w-20 weight especially in hotter climates.

After doing about a 1 minute autocross run I've hit about 210F and back at idle it results in an oil pressure around 22psi. I've never tried the same setup with 0w-20 so I don't have any comparative data.

[ft_sjo]

20 and 30 have similar viscosities at hot running temps so it makes little difference in this context.

[cf6mech]

Talking to Ken Stout about my car and tracking, ( they are contesting A FRS in the Pirrelli World Challenge Series) He strongly suggested running a accusump oil system due to the pressure drops, he added it would be cheap insurance . Guess they had some pressure extremes north and south during extensive testing. They are running a dry sump.

[mike the snake]

The gold standard for oil pressure is 10 pounds per 1k rpm as far as I know.

100+ lbs oil pressure seems super high, even at high rpm's. I'm not familiar with Subarus though.

seems like a recipe for blown oil lines.

[rice_classic]

Originally Posted by cf6mech

Talking to Ken Stout about my car and tracking, ( they are contesting A FRS in the Pirrelli World Challenge Series) He strongly suggested running a accusump oil system due to the pressure drops, he added it would be cheap insurance . Guess they had some pressure extremes north and south during extensive testing. They are running a dry sump.

I want to echo this. Not necessarily to say an accusump is mandatory but Dave: check your pressures (if you can) during high G cornering. You might see pressure drops in long sweepers.

If that is happening, and robispec can probably verify, an accusump will fix that but also a baffled oil pan can be a simpler, and more cost effective solution as well.

Dave: Since you're familiar with Hondas, think D16 vs B16 (or B18) pans. The D16 are factory baffled and I can run 1.6 G's all day long without a problem but the B-series pans are just empty buckets. We built a 9k rpm B18c5 @ 12:5:1 CR and solved the oiling issues 100% by simple pan baffling.

Just something to look at next time you're at the track.

I don't like your latest oil temp vs pressure results. The reason is that the measurement isn't taken when hot. 75C is "startup temp" for all I'm concerned. That's only 167F! You're oil isn't even up to temp yet, so there should be no surprise that at redline you're @ 100psi. In my race car, I don't even like revving past 4k until my oil is roughly 180F and I race with it at 240-260F.

Get your oil temp to 220 at least and check pressure. Increase or decrease oil viscosity as needed with that reading.

That's my $.02

[brillo]

So I'm going to install an oil pressure gauge and test my own pressures. I assume I can tap the oil pressure switch location. Anything special I need to know about removing the switch? Will oil dribble out or gush? Will removal of the switch freak out the Ecu?