Oil pressure drops on race track in S corners

[zeroomega]

I did some data logging on oil pressure at Thunderhill West race track with a GR86 today and had some interesting(sad) discovery: the pressure seems to be quite steady at long sweep corners but drops significantly at fast S corners during load transitions. At TH west, the pressure drops significantly on 3 different locations on the track. (1) At T1 to T2 left to right transition; (2) T4 to T5 left to right transition; (3) T7-T8-T9 at hill top.

The pressure drop at T4 to T5 is the most severe one as the pressure dropped from around 60psi to 25psi for nearly 3 secs. While it is hard to tell if that is going to cause significant damage to the engine, but it is definitely not ideal. No wonder why Japanese GR86/BRZ cup recommends oil pan baffles. But at the same time, I am wondering how much these baffles could help as some designs seems to be blocking oil return flow.

The car was using GT Radial SX2 tires, which has similar grip (maybe even less grip) compared to the OEM PS4 tires. Except for the extra front camber, there is no other suspension mods. It is likely with stickier tires, the oil pressure drops could be more severe. Oil pressure sensor is installed at engine block oil galley port.

Overlaid video:

Thoughts?

[KillerBMotorsport]

Do you have a logs with telemetry?

What you're seeing might be cause by a couple of different things. I'd like to see full logs showing oil pressure, oil temp, speed, RPM, AVCS L, AVCS R, throttle position and ideally the telemetry showing lateral loads in all direction.

It could be what's called Slosh. Most common in auto-x where there are rapid direction changes.

It does not sound like Surge which, is seen at sustained lateral loads.

It there are throttle/braking or RPM/load changes being made during in these particular sections of track, it could be due to 'normal' AVCS modulation. Not uncommon for EJs to lose 30+ psi under the right AVCS conditions.

Managing it (or not) best will depend on the cause.

[Robertw]

The GR Cup cars are running Greddy oil pan baffles right?

[KillerBMotorsport]

OK, so I missed the vid the first time around.

This thing does not like taking right hand turns. What was the oil level?

We're still new to the FA24 platform, but the engine configuration is typical of all Suby H-4 engines. IMO what you're seeing here is a combination of engine design and track elevation changes amplifying those conditions. The LH-Head is a few inches further back than the RH-Head. What that means is that under certain condition; Right had turn on throttle and/or elevation changes, allows oil to easily flow into that LH-Head.

Odd because it seems consistent and much more pronounced than I've ever seen on a stock-ish setup. This is why my first question in on oil level, because that would make sense here. Have you tried running a higher oil level. We've not tested the FA24 yet, but so far, the EJ engines are very tolerant of overfilling, by a quart without issue.

Your data and conditions may make you a good candidate for product testing

[timurrrr]

Originally Posted by KillerBMotorsport

This is why my first question in on oil level, because that would make sense here.

That was my first question as well.
He separately told me he was running oil at max.

[alex87f]

Were we seeing similar drops on 1st gen cars?

Also, are the 2nd gens equipped with a proper pressure sensor or is this aftermarket?

[timurrrr]

Originally Posted by alex87f

Also, are the 2nd gens equipped with a proper pressure sensor or is this aftermarket?

No "proper" pressure sensor from the factory, this is aftermarket/DIY.

[zeroomega]

Originally Posted by KillerBMotorsport

Do you have a logs with telemetry?

What you're seeing might be cause by a couple of different things. I'd like to see full logs showing oil pressure, oil temp, speed, RPM, AVCS L, AVCS R, throttle position and ideally the telemetry showing lateral loads in all direction.

It could be what's called Slosh. Most common in auto-x where there are rapid direction changes.

It does not sound like Surge which, is seen at sustained lateral loads.

It there are throttle/braking or RPM/load changes being made during in these particular sections of track, it could be due to 'normal' AVCS modulation. Not uncommon for EJs to lose 30+ psi under the right AVCS conditions.

Managing it (or not) best will depend on the cause.

Please DM me your email address, I can send you the original AIM data logs. But I didn't log AVCS L /R since I haven't figure out the CAN ID for these values. If you know the CAN IDs, I can log them next time.

Oil is at full mark, I check it every session. Haven't consider overfilling it as I am concerned it will cause more issues than solving them.

There was a video in Chinese that a guy experienced oil pressure drop to around 4psi in similar esses corners. So I doubt the pressure drop I experienced are from AVCS.

[zeroomega]

Originally Posted by Robertw

The GR Cup cars are running Greddy oil pan baffles right?

Did U.S. GR Cup mentioned they are using oil pan baffles? I only know Japan GR86/BRZ cup car has a proved list of baffles and Greddy one is one of them. However, I didn't see any test data proving these baffles improves the stability of oil pressures, that is why I am hesitate of installing one.

[NoHaveMSG]

Originally Posted by alex87f

Were we seeing similar drops on 1st gen cars?

Also, are the 2nd gens equipped with a proper pressure sensor or is this aftermarket?

Yes, I have seen down into single digit on my first gen.

[zeroomega]

Originally Posted by alex87f

Were we seeing similar drops on 1st gen cars?

Also, are the 2nd gens equipped with a proper pressure sensor or is this aftermarket?

I think someone mentioned gen1 has similar oil pressure drops. I didn't test it on my gen1 so I don't have any data to compare.

The oil pressure sensor is the "30-4407" 150psi AEM oil pressure gauge. Sensor installed to the block oil galley port. I use customized hardware to pass through the pressure data to an AIM Solo DL2 for data logging.

[KillerBMotorsport]

Originally Posted by zeroomega

Please DM me your email address,

sent and received. Will review and get back to you.

Originally Posted by NoHaveMSG

Yes, I have seen down into single digit on my first gen.

Same conditions? Do you have logs?

What are you doing to manage it?

[NoHaveMSG]

Originally Posted by KillerBMotorsport

sent and received. Will review and get back to you.







Same conditions? Do you have logs?



What are you doing to manage it?

I have an innovate ssi-4 connected to an innovate logger and gauges but I haven't gotten it setup to properly read rpm and that project fell by the wayside while I deal with other things. I wanted to start logging it. Oil pan baffle going in this winter.

[mpg9999]

Originally Posted by zeroomega

I think someone mentioned gen1 has similar oil pressure drops. I didn't test it on my gen1 so I don't have any data to compare.

The oil pressure sensor is the "30-4407" 150psi AEM oil pressure gauge. Sensor installed to the block oil galley port. I use customized hardware to pass through the pressure data to an AIM Solo DL2 for data logging.

Would you mind sharing your exact datalogging setup? I'd love to capture some oil pressure data while autocrossing.