Oil pressure drops on race track in S corners

[JDMChris]

Originally Posted by zeroomega

Local 86cup fb group. Gen1 car with 2015 engine. I don't know the owner so I don't know more details. I guess now you see one example.

It means nothing without knowing variables. He could have been low on oil for all we know. Could have been running crappy oil. Who knows.

[Dzmitry]

Just btw, I don't believe this was linked anywhere here. Good read on a large discussion over gen1 FA20 oiling issues. Worth skimming and reading through most of the thread (11 pages) for you @KillerBMotorsport, if you haven't seen it yet. Some good testing and data provided in there.

https://www.ft86club.com/forums/showthread.php?t=134863

[timurrrr]

Originally Posted by Dzmitry

Just btw, I don't believe this was linked anywhere here. Good read on a large discussion over gen1 FA20 oiling issues. Worth skimming and reading through most of the thread (11 pages) for you @KillerBMotorsport, if you haven't seen it yet. Some good testing and data provided in there.

Forgot to paste the actual link?

[JDMChris]

Originally Posted by zeroomega

Local 86cup fb group. Gen1 car with 2015 engine. I don't know the owner so I don't know more details. I guess now you see one example.

It was a junkyard engine. So who knows what it could have been. He did mention temps and pressures were fine.

[zeroomega]

Some updates after last weekend at Buttonwillow.

TL;DR, I don't think Syms Racing oil pan baffle is quite useful. But it doesn't seem to make the matter worse.

I did a side by side comparison of oil pressure log with and without Syms Racing oil pan baffle (a picture can be found from https://www.japanparts.com/parts/detail/?id=64611). See the data log image (click it to see the full res image) below,
* Red is logged with the oil pan baffle installed with oil temperature around 220F on Jan. 28, 2023
* Green and blue is logged without oil pan baffle with oil temperature around 210F on Nov. 25, 2022

(disclaimer, I am new to Buttonwillow track so my driving might not be consistent enough)



If you are familiar with Buttonwillow 13CW layout (see the map below), all the turns that has oil pressure drops marked in the image are right turns. And the pattern is quite similar, it starts with a hard braking and a right turn with more than 1g lateral.



* Turn Off Ramp: With baffle, it looks like the pressure is even slightly lower to 22psi. But I am not too worried about this turn as the RPM dropped below 4k and pressure recovered before throttle increased.
* Turn Club Corner: Pressure dropped for less than 0.5sec and with baffle, the minimal pressure is marginally improved.
* Turn Riverside: Oil pressure is oscillating regardless of presence of baffle. This is a 6sec 1.1g right turn with a little bit positive camber. However, unlike other turn marked here, the car enter the turn with throttle instead of braking.
* Turn Phil Hill: This is a right turn with hill top. With baffle, the minimal pressure is improved from 30psi to 40psi. The pressure drop lasted for around 1 sec.
* Turn Sweeper: This is a long double apex flat right turn with around 1.1g. Oil pressure is oscillating regardless of presence of baffle.

So, yeah, the syms oil pan baffle (even though it is on Japan's 86cup approve list) doesn't seem to improve or worsen anything, at least at Buttonwillow CW13. But the pressure drops at BW is also not as bad as what I seen at Thunderhill West, where at T5 the car dropped to 30psi for around 5 sec.

I don't think the pressure drops I experienced are AVCS related. If it is, I should see the same pressure drops in left turns. But from the log, the pressure drop looks simply correlated to right turn or hill top (or both), so I highly suspect it may be simply due to the oil pick up is installed to the passenger side. It would be great if we could have a transparent oil pan and mount a camera there to see what is actually happening. The AVCS is probably responsible to the slight pressure drop when engine RPM is near red line. But I don't think that amount of drop should be worried about.

I personally don't use the case that a shop car with certain mods survived a track or not as an indicator on whether that platform or mod is reliable on track. Especially without published data logs on the car's running conditions. And unfortunately not many shop or vendor will publish that data. A single car survival or failure in a certain track for a single HPDE track day doesn't mean much. If it survived a 24h endurance racing, that is a different story. But previous gen 86 doesn't have a good track record in endurance. IIRC TAPG's 86 blew the engine in Thunderhill 25hr in 2018. So I won't say the car/engine is alright just because I didn't see any failure at some tracks. :-) In fact, I have seen 3 FA20 engine blows personally, though they may not related to oiling. With FA24, it would take years for us to know if it better or worse than previous gen FA20. With this uncertainty, I prefer to play it safe and do logging if I can. In the worse case when it fails, I at least have some data to do a post mortem.

Another issue is that for most HPDE/ Amateur time trial drivers, setting up data logs that is not directly from ECU is quite complicated. When I decide to log oil pressure, there is no off the shelf product (that is economical enough) that I can use to log the data into a AIM Solo DL2 or some data logging apps like RaceChronos. I have to build 3 iterations of circuit boards to read oil pressure sensor input and send it over CAN bus so it can be logged. Below are the boards I built for logging the oil pressure:


I would hope some company can build a similar product with reasonable price. The market for this might not very big or profitable though.

[nissanfanatic]

Originally Posted by zeroomega

* Turn Riverside: Oil pressure is oscillating regardless of presence of baffle. This is a 6sec 1.1g right turn with a little bit positive camber. However, unlike other turn marked here, the car enter the turn with throttle instead of braking.

Doesn't the pickup sit towards the rear of the pan? It appears to based on the pictures I looked at. That would track with the drop happening under right handers with deceleration, and not as bad under accel.

Think it would be possible to give a few brake pedal stabs next time out on hard right handers?XD
I've done some basic hardware stuff like UART stuff on routers, rpi stuff, etc so I'll start looking into building something similar to what you have unless you happen to open source your stuff first.

[zeroomega]

Originally Posted by nissanfanatic

Doesn't the pickup sit towards the rear of the pan? It appears to based on the pictures I looked at. That would track with the drop happening under right handers with deceleration, and not as bad under accel.

Yes, the drop is not as bad as some brake and right turns like "off ramp". But it still drops, probably because lateral g is way higher than longitudinal g and it is a long corner so the pump depletes the pan eventually.

Originally Posted by nissanfanatic

Think it would be possible to give a few brake pedal stabs next time out on hard right handers?XD

I would avoid trail braking into Riverside, that is asking for trouble XD. Last Saturday is a timed event so I need to prioritize lap time instead of doing experiments. But it would be nice to experiment different braking strategy on other slower technical hard right turns to see how the oil pressure reacts.

Originally Posted by nissanfanatic

I've done some basic hardware stuff like UART stuff on routers, rpi stuff, etc so I'll start looking into building something similar to what you have unless you happen to open source your stuff first.

The 2nd iteration is open-source already: https://github.com/zeroomega/canmim it contains reference circuit schematic and Gerber file so you can order the PCB from some PCB manufactures and build your own copy. I am still cleaning up the software for the 3rd iteration board so it will take some time for me to update the repo with the 3rd iteration. But this board is mostly work for GR86 that the CAN data is logged from ASC unit, not the OBD2. If you have a gen1, you probably have to implement your own programming to work with the OBD2 CAN protocol.

[Blighty]

Originally Posted by KillerBMotorsport

snip
...

On the dyno is where it needs to be done. It's a controlled environment. You monitor inlet/outlet pressure and flow. You do pulls and recharge the accumulator at various RPM points and watch what happens.

Would a dyno be able to replication the low pressure conditions though? The pressure drops are still when the pump is trying hard, so faking pressure through modifying the pump cycle would not be a great test for instance.

[KillerBMotorsport]

Originally Posted by Blighty

Would a dyno be able to replication the low pressure conditions though? The pressure drops are still when the pump is trying hard, so faking pressure through modifying the pump cycle would not be a great test for instance.

Again, the pressure drop off or light throttle is not the concern here. Pressure drop at WOT is very much the concern, and easy to duplicate on the dyno.

The accumulator would be drained to whatever its minimum would be and recharged under load. I would do it at 1,000 RPM increments to start with. On the dyno you can prolong the pull, shorten it, or hold it at a certain RPM and just hold full load continually. So, you can set up some pretty severe conditions while very closely monitoring oil pressure, temperature and flow.

[Dzmitry]

Originally Posted by timurrrr

Forgot to paste the actual link?

LOL, yes I did.
https://www.ft86club.com/forums/showthread.php?t=134863

[Ansix Auto]

We actually built a prototype unit as well that can send oil pressure to the Canbus for logging. We're evaluating the feasibility at the moment since it's quite labor intensive to build. If people are interested in this, please let us know. Maybe we can do a small production run or group buy.

@zeroomega I noticed both baffles you've tested don't have trap doors. Would that be something you'd be interested in? We can send you ours to try out.

https://ansixauto.com/2022-brz/gr86-...il-pan-baffle/

[nissanfanatic]

Originally Posted by Ansix Auto

We actually built a prototype unit as well that can send oil pressure to the Canbus for logging. We're evaluating the feasibility at the moment since it's quite labor intensive to build. If people are interested in this, please let us know. Maybe we can do a small production run or group buy.

Would a DIY kit be more feasible?

[Ansix Auto]

Good question.. I'm not sure if I have a good answer. A DIY kit is a bit of a half measure, you might as well just fully DIY then?

[zeroomega]

Originally Posted by Ansix Auto

We actually built a prototype unit as well that can send oil pressure to the Canbus for logging. We're evaluating the feasibility at the moment since it's quite labor intensive to build. If people are interested in this, please let us know. Maybe we can do a small production run or group buy.

@zeroomega I noticed both baffles you've tested don't have trap doors. Would that be something you'd be interested in? We can send you ours to try out.

https://ansixauto.com/2022-brz/gr86-...il-pan-baffle/

Thanks for the offering but I would prefer to avoid using baffle with rubber trap doors as some Japanese drivers tested the cusco oil pan baffle (which also use rubber trap doors). The rubber trap doors fall off and clogged the oil pick up.

From my test data, I don't think the horizontal oil pan baffle is enough to the pressure drop issue, there probably needs vertical baffles near the driver side lower pan to mitigate the pressure drop in right hand corners.


I agree on labor intensive part of building the board. For DIYers like me, it took me 2hr to assemble a board with SMD components. I won't make a profit if I decide to sell it at low price. The price can be greatly reduced if the board is pre-soldered from a manufacture like JLCPCB though.