Oil pressure drops on race track in S corners

[KillerBMotorsport]

Originally Posted by nissanfanatic

It would be nice to test this on a skidpad or something where you can load the car laterally and then mess with accel/decel to try and reproduce the pressure drop.

Yes and no. A skidpad is a very specific condition and Suby boxer engines don't like them. It's a sure-fire way to blow them up if you're not careful.

In short, the outside facing head fills with oil given enough time. We see the same thing happen on long and/or banked corners like the Nurburgring's Karussel. It's banked and +180°. Competitive Subies would slow down considerably on this corner until oiling solutions were developed.

IMO, this starvation is happening because oil is sloshing into the timing cover, which is a big cavity, and roping on the chain causing a significant drop in oil level. The pan is perfectly shaped to channel oil up and forward, and the upper pan/block have more open area on the left side for oil to pool under braking right turns.

Horizontal baffles are not the solution for this type of condition, which is why some have seen no change when using them. I have a handful of prototype baffles that are to be made next week and will be testing them. Anyone who seriously tracks, has datalogging capabilities, and is brave enough to test prototype parts is more than welcome to reach out to us for upcoming beta testing opportunities.

[DriveDriftDogfight86]

Originally Posted by zeroomega

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.

I'm not going to read all 9 pages of this, but I thought the stock GR86/22+ BRZ already comes with oil baffles from factory.

Start @ 6:34

[Blighty]

Originally Posted by DriveDriftDogfight86

I'm not going to read all 9 pages of this, but I thought the stock GR86/22+ BRZ already comes with oil baffles from factory.

Start @ 6:34

Funny, I've watched this a few times back when it came through, but I didn't recall these nuggets at all. Getting old!

But yeah, are there any full teardowns videos of the FA24D yet?

[Blighty]

Originally Posted by Blighty

Funny, I've watched this a few times back when it came through, but I didn't recall these nuggets at all. Getting old!

But yeah, are there any full teardowns videos of the FA24D yet?

I forgot there was one with FTSpeed. I couldn't see both sides of the casing, didn't noticed anything special compared to an FA20 breakdown, but I dont know what this might look like.

What I did notice was the new block has a LOT more ribbing. There is almost none that I could see on the old FA20.

[zeroomega]

Originally Posted by Blighty

Funny, I've watched this a few times back when it came through, but I didn't recall these nuggets at all. Getting old!

But yeah, are there any full teardowns videos of the FA24D yet?

Upper oil pan has some metal shielding below the crank shaft, if that can be called as baffle. The same structure is already present in gen1 FA20.

Lower oil pan (the one people drop for RTV cleaning) doesn't have any baffle at all.

What is already present on the car to prevent oil sloshing is actually not very relevant now. They are not sufficient to prevent oil pressure drops. The pressure readings doesn't cheat, the engine does have oil pressure drop behavior at certain right turns with large lateral G. We just don't know for sure if that is severe enough to be a problem.

[KillerBMotorsport]

Originally Posted by zeroomega

Upper oil pan has some metal shielding below the crank shaft, if that can be called as baffle. The same structure is already present in gen1 FA20.

Lower oil pan (the one people drop for RTV cleaning) doesn't have any baffle at all.

What is already present on the car to prevent oil sloshing is actually not very relevant now. They are not sufficient to prevent oil pressure drops. The pressure readings doesn't cheat, the engine does have oil pressure drop behavior at certain right turns with large lateral G. We just don't know for sure if that is severe enough to be a problem.

^ this right here.

The design changes are marginal. The guy in the vid seems to express 'significant upgrades', but the data says otherwise.

[nissanfanatic]

Just more observations: I just watched the last three of @zeroomega's videos (since another new one popped up on youtube for me today) and on each of them, it really seems like combined gees of 1 in lateral/long on right handers (quadrant 2) is where this occurs:





Each of the significant drops starts around that area on the gee circle. It also occurs in situations where I'd think there has been enough time for oil to return to the pan, such as at 30 seconds in on this video:

It doesn't seem to be braking alone as I don't see it occur under straight line braking, but it does occur at the slightest amount of lateral accel on right handers (again, anything in quadrant 2) that exceeds 1g combined...

[KillerBMotorsport]

IMO, braking followed by a right-hand turn is causing sloshing into the timing cover and into the left had side of the timing cover, where there are no drains. As the car straightens out, oil can flow back into the pan through the center drain back from the timing cover.

The timing cover is a HUGE cavity and the oil pan shaped like a finnel into it, doesn't help. Additionally, you have a high-speed chain in there that will draw (rope) and hold for a period, a decent amount of oil.

This would explain why flat horizontal baffle plates (in the pan or between upper and lower pan) do little, since the upper pan holds more oil than the lower.

If this baffle that blocks the timing cover opening works well for us, it will be a simple and effective solution. We'll find out...

[dragoontwo]

Originally Posted by KillerBMotorsport

IMO, braking followed by a right-hand turn is causing sloshing into the timing cover and into the left had side of the timing cover, where there are no drains. As the car straightens out, oil can flow back into the pan through the center drain back from the timing cover.

The timing cover is a HUGE cavity and the oil pan shaped like a finnel into it, doesn't help. Additionally, you have a high-speed chain in there that will draw (rope) and hold for a period, a decent amount of oil.

This would explain why flat horizontal baffle plates (in the pan or between upper and lower pan) do little, since the upper pan holds more oil than the lower.

If this baffle that blocks the timing cover opening works well for us, it will be a simple and effective solution. We'll find out...

Does the timing cover need to come off to install this?

[KillerBMotorsport]

Originally Posted by dragoontwo

Does the timing cover need to come off to install this?

No it does not. The baffle is installed with the pan removed.