Oil starvation on Track. GReddy baffle plate data
TL;DR: I installed the GReddy oil pan baffle plate specifically to address FA24 oil starvation. I then logged 12 track laps with a real oil pressure sensor. It did not fix it. Worst reading was 1.79 bar (26 psi) at 5300 rpm, and 100% of my sub-2.5 bar events happened in right-hand corners. If you are buying this part expecting protection, please read this first.
I see the GReddy baffle plate recommended constantly as the budget answer to the FA24 oiling problem. I bought into that. I want to put actual numbers out there so the next person can make a better decision than I did.
Setup and conditions
- 2025 GR86 (ZN8), JDM import, FA24, 6MT
- Oil: 5W-30, fresh,
overfilled 0.5 L
- GReddy oil pan baffle plate installed (PN 13515903)
- Stock oil pan, stock pickup, no oil cooler
- Speedway — 1.9 km, mixed direction, several long right-handers, 12 laps, ambient warm
- Logging: Ansix CANbus kit + OBDLink CX into RaceChrono, real oil pressure sensor on the CAN bus (not the idiot light, not an OBD-II PID estimate)
Establishing a healthy baseline first
Before claiming anything is wrong, I filtered for hot oil, throttle >20%, and lateral G under 0.3 to get a clean "what should this engine make" number:
RPM |Median oil pressure
4500–5000 |4.97 bar (72 psi)
5000–5500 |4.90 bar (71 psi)
5500–6000 |4.97 bar (72 psi)
6000–6500 |4.90 bar (71 psi)
6500–7000 |5.10 bar (74 psi)
7000–7500 |5.24 bar (76 psi) So the pump and the engine are healthy. Flat, strong, ~5 bar across the whole usable range. Whatever goes wrong is a pickup/slosh problem, not a mechanical one.
The actual result
I sorted every sample above 3000 rpm by corner direction. I verified the sign convention independently by computing signed path curvature from GPS and correlating it against the CAN lateral accelerometer (r = 0.87), so this is not me guessing which way is which.
Condition |Median |5th percentile |Minimum |% of samples >1 bar below baseline
Right-hand, >0.6g |4.69 bar |3.10 bar |1.79 bar (26 psi) |19.8%
Left-hand, >0.6g |5.10 bar |4.21 bar |2.76 bar |1.6%
Straight / low-G |4.97 bar |3.86 bar |2.62 bar |2.4% Threshold breakdown above 3500 rpm:
- Below 3.0 bar (44 psi): 94% occurred in right-handers
- Below 2.5 bar (36 psi): 100% in right-handers
- Below 2.0 bar (29 psi): 100% in right-handers
That asymmetry is the FA24 signature everyone has been documenting for years. The baffle plate did not remove it.
It is not sensor noise, and it is not heat
Two things people will reasonably ask, so I checked both.
Noise: noise does not care which way you are turning. A 20:1 ratio between right and left cannot come from a flaky sensor. And it is not a single-spike artifact either — on lap 9 I spent 2.5 continuous seconds loaded at −0.9 to −1.5 g and pressure sawtoothed 5.1 → 2.7 → 5.1 → 3.0 → 3.2 → 3.7 bar. That is the pan repeatedly uncovering and re-covering the pickup.
Heat: the worst events happened at 113–120°C oil temp. My clean 4.9–5.2 bar baseline samples were taken at the same temperatures. Coolant never went past 94°C. Hot thin oil is not the explanation here.
It got worse as the session went on
Percentage of samples running more than 1 bar below expected pressure, per lap:
- Lap 1: 2.5%
- Lap 3: 5.2%
- Lap 9: 9.6%
- Lap 10: 18.6%
- Lap 12: 11.1%
My fastest lap was also one of the three worst laps for oil pressure. That is the trap with this platform — the better you drive, the more you hurt it.
Important caveat that makes this worse, not better
My oil pressure channel logged at 7.2 Hz (roughly one sample every 120 ms). Out of 232 discrete low-pressure events, 158 were a single sample. That means the true minima are almost certainly lower than what I recorded — I am sampling too slowly to catch the bottom of these dips. 1.79 bar is my floor, not necessarily the engine's floor.
I am raising the logging rate before the next session and will post an update.
Why I think it can't work
The baffle plate addresses oil movement inside the pan. But on a flat-four a large amount of oil ends up parked in the heads and the timing cover under sustained lateral load, and no plate in the sump can pull it back. Verus have publicly said their own first attempt was a baffle system and it didn't do what they expected, which is exactly why they ended up designing a whole new pan. Killer B's plate showed the same thing in independent track testing years ago. My data is just one more confirmation of a pattern.
To be fair to GReddy: their marketing talks mostly about oil migrating into the timing chain cover under braking G. It's possible the plate does something there. What it clearly does not do is protect you through sustained high-lateral right-hand corners, which is the failure mode that actually kills these engines.
Full track setup, for context
Nothing exotic, and nothing that should stress the oiling system beyond what any tracked GR86 sees. If anything the grip level is what makes the problem visible — I'm pulling around 1.5 g peak lateral.
Engine / breathing
- Tomei Expreme UEL header Ver.2
- Custom catless front pipe with dual resonators
- HKS Spec-L II catback
- GR Performance intake
- EcuTek tune (three maps: stock / track / pop-bang)
Chassis
- H&R lowering springs
- Camber bolts (SPC 81260) — alignment currently −1.3°/−1.4° front, −1.1° rear
- APEX ARC-8 17x9 ET42 with Yokohama A052 245/40R17
Oiling (current)
- 5W-30, stock pan, stock pickup, GReddy baffle plate, no oil cooler
Logging
- Ansix CANbus kit + OBDLink CX + RaceChrono
What I'm doing next
The baffle plate is staying in — it's not hurting anything — but I'm treating it as a placebo, not a solution.
I'm going with the Formula Delta oil pan. Increased capacity plus proper integrated baffling is the only approach that actually attacks where the oil goes on this engine, rather than trying to manage it after it's already gone. Verus's pan is the other serious option and I looked hard at it, but Delta works out better for me on cost and shipping from Cyprus.
In the meantime I'm running a slight overfill and I'm not going to attack the long right-handers at Achna at full commitment.
If you track a 2022+ GR86/BRZ: please buy a real oil pressure sensor before you buy any "fix." You cannot evaluate a solution you can't measure, and the factory gauge will tell you absolutely nothing until it's already too late.
Happy to share the raw session file with anyone who wants to run their own analysis on it.