BRZ & GR86 Oil Starvation Even In Stock Form - [2024 Current State Technical Discussion]

[@KevinWong_BRZ]

Thanks for having us on the channel! With three, maybe even a fourth, second gen twin amongst the three of us, we have a lot on the line to figure how to make this car perfect on top of having the right knowledge to address the issue systemically! Hoping to address everything in a proper engineering approach!

[@latapx]

I have over 36 hours of track time on my 2023 BRZ. It's been fed a steady diet of 300V 5w30 and I've been logging oil data for over a year. Overfill helps. Removing OE heat exchanger gives you a 5psi bump. Cooler oil is key. You may only get 5 to 7 psi better straightline pressure with cooler oil (say 230F vs 250F) bit the pressure drops are mitigated. I've seen "slosh drops" from bumps at T17 Sebring or quick left to right transitions. They are instantaneous. Then there are "starvation drops" on longer right handers where pressure gradually drops and comes right back when the corner is done. According to my data, the sweeper type corner drops are the same stock suspension vs coilovers and sticky tires. The slosh drops get worse with grip. I'm currently on 255 RC1 and MCS coilovers. I'm also running a larger oil cooler, Setrab 920, which has less pressure drop and larger lines.

[@neildesai21]

@KevinWong_BRZ Latapx and I have worked together on this solution. We have extensive data from Sebring. Second to COTA this is where the majority of GR Cup cars blew motors. Remove OE cooler to gain the psi an aftermarket cooler will lose. We can even provide data on btu/hr and pressure drop through HX on the setrab 920 core.

[@KevinWong_BRZ]

@@neildesai21 and @latapx - very good data! I'll try to get ahold of both of you! Do you guys have a way to reach out to me or me to you? I checked your channels and there's no contact button.

[@practicaldriver]

@@latapx amazing data thanks for sharing.

[@ciello___8307]

@@neildesai21i know versus engineering is developing a new higher capacity oil pan and baffle package, its on youtube. They also suggested an overfill and of course the oil cooler

[@neildesai21]

@@ciello___8307 yup in talks with them to help them make sure the design leaves enough room for aftermarket headers!

[@darksunrise8777]

Love the analysis, but this issue has largely been solved by Toyota/GR Cup engineers. Setrab 915 oil cooler (delete factory heat exchanger), M1 0w40 oil, 0.7q overfill (7q total) and a stock oil pan with angled baffle. None of the 20+ GR Cup teams lost any engines due to oil starvation last year on that setup. This is running Conti slicks + aero. Pretty solid validation that setup works. No need to re-invent the wheel IMO, just use what is proven.

[@KevinWong_BRZ]

According to 900BRZ, they're still seeing pressure drops even with the standardized equipment they're running. I would say they have have raised the bar to get to failures but I don't think its been eliminated.

[@sikrip]

Nice info there. Thank you for sharing. I have been logging oil pressure on my completely stock GR86 since my first track day. My observation is that on a stock car you need four things: 1. Use high quality at least 5w30 oil 2. Overfill by 0.5L-0.7L 3. Do not let the oil to go higher than 120-125C 4. Short-shift where needed (for example by short-shifting on a right double header I have no drops [kzbin.info/www/bejne/eGjQi52ebbSFeKs] ). If the stock cooling setup does not give enough time on track(for sure it depends on the layout of the track), then add an oil cooler.

[@KevinWong_BRZ]

Oil can go up to 130-135 deg C no problem, I would cap it at that though. Great work on your part!

[@jagymeister]

Im doing exactly the samw with my GR86.

[@kasio22B]

There are more useful information discussed here than yesterday's GR86/BRZ fan fest/promotion day in Japan👍

[@eXpeDiEnt89]

This is fascinating and informative. I have a first-gen twin ('14 FR-S) that's a spirited daily and about to hit 100k miles. It's only been to the track once but has spent many nights carving mountain roads an hour or more away from home. I follow the maintenance schedule and have the oil analyzed for every other change. This video made me feel validated for what I've done with the car. I have an air/oil separator as a supporting mod and a handfull of other mods, but mostly supporting for reliability. I still run 0W20, but I think I'll keep some 5W30 in the garage to top off between changes. Excellent work on the research and thank you for sharing your experience.

[@stevemartegani]

As someone who has worked for Subaru in the past, I highly doubt there will be any updates for the N/A FA24... The WRX engine has the same issue, and Subaru seems intent on abandoning the BRZ model line with the extremely low deliveries to dealers and the lack of advertising over the course of the last 10 years. Also, a brief history of Subaru's engine issues... Back in the 1970's, Subaru had the EA63 engine. It was a 1.4L OHV Boxer that used "Wet Sleeve" cylinders that had copper gaskets holding the sleeves in place. Those engines were NOTORIOUS for headgasket failures due to the copper ring distorting. Subaru came out with a completely redesigned shortblock later that solved the issue, by creating a significantly better designed traditional closed deck. The EJ18's and EJ22's in the 1990's were VERY stout compared to the EJ25's that arrived later, they even sold "Sand cast" EJ20 and EJ22 short blocks for turbo applications in the 90's that were very well manufactured, but abandoned due to production costs. The N/A EJ25's especially the EJ251 and EJ253 had the headgasket issues that Subarus became notorious for (and the only real "modern" Subaru engine that had regular headgasket issues) as the result of using a coating on the factory headgasket that failed. The Turbo headgaskets on the EJ255/EJ257 have significantly fewer failures, and actually solve the issue... BUT Subaru to this day still sells the bad gaskets for the N/A engines and refuses to acknowledge the issue. And of course, the Ringland failures with the EJ255 and EJ257... An "Updated" piston design came out later for the 2018 Type-RA and became the standard block from 2019-2021 STI, but Subaru again never acknowledged the issue (because it would lead to a massive recall costing them crazy money) and it technically never solved the problem, because those engines still have ringland failures. So I would be SHOCKED if they acknowledged this issue with the FA24. The recall campaign would bankrupt the company considering the same design is in Ascents and Outback/Legacys with the Turbo FA24's, not to mention the 2022+ WRX's.

[@KevinWong_BRZ]

Cool history! That said though, given this problem is really a 1% of customer base (or less), its probably not worth it for them to address directly - which is sad for me as an engineer.

[@momsbasement656]

The WRX FA24 does NOT have the same issue. Multiple tests show it has rock solid oil pressure in every condition.

[@stevemartegani]

@momsbasement656 That's not what I've been hearing. But if thats the case, a baffle won't be the solution since they share that same part number. The oil filter is horizontal versus vertical on the WRX upper pan to make clearance for the Turbo/header, and the pickup is slightly different but angled the same direction. Heads and block castings are different to accommodate oil/coolant flow to/from the turbo too.

[@jrfish007]

Pretty sure the turbo FA24 has some differences internally, also Ascents and such probably do turns hard enough to worry about.

[@BuildinProgress]

For the oil cooler core/heat exchange - Setrab lists cooling capacity in BTU/hr(they also list a HP number). They also list capacity and pressure drop measurements for all of their cores. This is not cheap stuff but it is significantly better than just about anything else out there. In case you want a core that has some actual real data behind it not just "19 row core" maybe worth a try!

[@KevinWong_BRZ]

Thanks for the heads up! Thanks to people like yourself, I have indeed found Setrabs technical information but still need more to complete the duality of pressure drop and flow details but it's a massive step forward!

[@geraldjustprojects]

Glad to hear that you guys got good data. And here is a couple extra info for anyone else here. Top oil galley is about a delta of 5psi compared to the stock oil pressure switch location. And oil coolers themselves don't have much of a pressure drop (compared to what other companies may say. And no we don't sell oil coolers so we are not bias). The benefits of a oil cooler helps out too as oil temp and pressure are correlated.

[@KevinWong_BRZ]

Thanks for making the I/O box and the RaceChrono profile to make this all work! 10/10 would recommend your product (no, I am not paid - I bought the I/O box myself). @900brz and I have been trading data on the oil coolers and they DO introduce 4.5 to 5 psi drop across just the CORE itself let alone the tubing. Having spent a lot of time in the heat exchanger business, its never zero dP for heat exchange - there's always a trade off. I am now going down the rabbit hole to all the rad manufacturers to see who is willing to share information on their cores... so far Setrab actually has partial information published but not enough for me to use. TO BE CONTINUED!!!

[@FormulaDeltaOG]

Thank you for having us on the channel. Really looking forward to our next recording session!! Would love to answer any follow up questions or entertain any thought experiments anyone may have, just tag me in the comments!

[@SlickRacerGuy]

Great video guys! My 1st gen has gone through about 5 engines now, 2 of them from catastrophic failures due to oil starvation. For the first 5 years it was fine, then I boosted it and dealt with overheating issues. After that issue was resolved, it got caged and then I lost two engines in a row from oil starvation due to high cornering (1.5-2G's), and they were also on long right handers! Now I have a built engine (2nd one) and it has the oiling upgrades necessary for Gen1's (KillerB oil pickup tube, Greddy baffle). I've done the Accusump route with bad results (1st built engine) so now I'm running without one with a half litre overfill (also 20w50 Amsoil since it is purely a track car now). Sounds like similar issues to Gen1 but now harder to upgrade the pickup tube. Hoping your video helps with exposure to get some solutions on the Gen2's. Cheers, Andre.

[@KevinWong_BRZ]

Curious as to what happened with the Accusump... care to share?

[@GregKeys-v2t]

This is the most informative discussion of the potential oil starvation issues with this engine I have seen. Thank you so much. I learned a lot and look forward to a solution from you!

[@practicaldriver]

I've done 25 track days and 23k miles on my '23 BRZ. I run 5qts 5w40 and 1 qt 5W30, so 6 qts total. Haven't blown up yet. I've seen 278F oil temps at Road America. I see 261F now with a 16 row Setrab cooler.

[@KevinWong_BRZ]

Do you have any oil logging equipment? I'm curious to see your pressures and oil temps, etc.

[@900BRZ]

Which 16 row core are you using? That’s an unusual amount of rows for Setrab. The only one I see on their website is a series 1, which has quite short plate lengths. 261 °F is still very hot.

[@practicaldriver]

@@KevinWong_BRZ I don't I'm sure it's not great on the pressure drops. Would love the versus pan but still waiting

[@practicaldriver]

@@900BRZ setrab series 6 pro line with 16 rows. Agree it's too small I need a larger one and need to improve the ducting to it. I have it mounted to the left of the radiator hidden away. I see your temps are in the 220s and 230s and that's where I need to get to.

[@Zaratium]

mine blew at 24k miles, and another one of my friends blew his at 25k miles. both of us were denied warranty

[@basedneeble7350]

Interesting... feeling like i should just stick with my miata after all. 😂

[@thejasoncao]

ND1/2 don’t have oil pressure issues, but I do believe they have trans overheating issues when pushed hard. Trans cooler!

[@KevinWong_BRZ]

@@thejasoncao no cars direct from the factory intended for standard road use are bulletproofed for track use. Tho I do admit Mazda gave everyone a real gem with the ND generation only needing a tranny cooler. I love the ND but I don't fit in one.

[@jrfish007]

@@thejasoncaoyes, but a trans is like $700, far cheaper than the FA24

[@nodrogkam]

Appreciate the data and the passion...working towards a solution to help the community. Really glad people outside of the states are tinkering too. I also think with more drivers who have fixed their blown motors outside of Subaru/Toyota's hands dilutes the data they have around failures.

[@Kgregg1991]

Great discussion. Excited to hear about the future conversations after more data is collected. Thank for supporting the community

[@KevinWong_BRZ]

Appreciate the support! We'll be needing more support soon! Stay tuned to this channel for more news as the Ontario Time Attack season progresses!

[@SereneSpeed]

I run 1-qt overfill of Motul 8100 5-40. I’m doing frequent oil changes & multiple oil analyses between changes. So far so good 🤞Thanks for all the info 🙏

[@TheDriversPerspective]

Continually see you post real videos, with real data. Props. The discussion about oil coolers is on point.

[@KevinWong_BRZ]

Thank you for the compliments! We weren't perfect and I've been compiling a list of things to reclarify and/or correct for part 2.

[@nigel_white]

I don't own either, but the concepts apply to any car and I appreciate the intelligent discussion.

[@AaronEscobedo]

ran across this in my feed - thanks for the measured data. I previously worked as an Engineer Controls Engineer for an OEM, but now work as the semiconductor field as an engineer. One thing I will say, they knew.

[@kc510]

Love the chat and info guys. I’ve ran mine at the track stock once so far with 6qts of 5w-30. Didn’t log oil pressure but did see 257°F oil temp. Could have been higher but that’s the highest I witnessed. Didnt blow up yet lol

[@jtworksoncars6341]

Yikes, 257F? You definitely need an oil cooler.

[@kc510]

@@jtworksoncars6341 to be fair it was 95° outside that day but yes. I want to see some more tests with oil coolers and pressure drop, though.

[@rjhick1]

Very good video. I appreciate in-depth discussion about problems like this 👍🏼

[@SGTPJ]

Awesome video! I hope this gets figured out in the next year or so. I have not tracked my car because of this issue, but i do love driving it daily

[@TODR34M]

I appreciate the mature discussion about these topics!

[@silvenshadow]

I do a 1qt overfill on 5q 5-30 and 2q 15-50 Mobil 1. I guess that's 7-37w ish but with some extra additives from the 15-50, short change intervals. Mixed light and heavy use. I definitely have to fully warm and cool the engine. I noticed far more temperature stability from even 5-30.

[@practicaldriver]

7qt total?

[@silvenshadow]

@@practicaldriver just a bit under

[@Iseenoobpeoples]

I got the old gen, I increased the pick-up tube size, horizontal baffle with rubber doors plus overfill with thicker racing oil.

[@thejasoncao]

Amazing contribution. Need more voices coming to similar conclusions so we can keep pushing forward.

[@JamesLapid-g6o]

Y’all should try Lucas Oil additive in the GR86 engine! Lucas makes the regular oil FLOW better by “sticking” to metal. My Cummins Diesel engine has over 300,000 miles and still has great compression and smoothness!

[@The89thAnarchist]

Great video, thanks for the deep dive!

[@richlee1374]

Thank you for a fasinating disussiion. I'd like to see a futher exploration as to why this oil staravtion only occurs on right handers. Its a boxer so you'd think the left and right banks of the engine are identical and the quantity of oil accumulating in the head should be the same left vs. right under identical g-loads? I suspect its the shape of th oil pan which is likely not symemtical left side vs. right side of the crank center line and/or the oil pickup tube is offset and angled differently left vs right. Care to comment?

[@KevinWong_BRZ]

We kinda hinted at it when @formuladelta took an in depth look at the upper oil pan. We'll cover it more in the next video.

[@DriversPaddock]

Watch the section where @formuladelta explains the upper and lower pan and detail and reply back with what you think. More to come 😉

[@richlee1374]

@@DriversPaddockI saw the difference in the upper oil pan left vs.right. However, I'm assuming under high g-load, oil is pumped out of the lower pan to the cam/valves and stays there until the g-load drops. Should be the same left vs. right. Starvation in right handers is resulting from the shape of the pan and the asymmetrical oil pickup not reaching the remaning oil sloshed to one side. Oli pickup is fine on left handers. Thoughts?

[@900BRZ]

Your mental model of the left and right banks of the boxer engine being symmetrical is not correct. In fact, they are highly asymmetrical. The right hand side of the engine (passenger side on LHD) is positioned forward in the engine bay. They need to be offset for the pistons to connect to the crankshaft. You can’t have pistons on each side of the engine connect to the crank at the same spot so they are offset. This means the timing cover is also asymmetrical. So in addition to the upper pan looked at in this video, there are countless other potential sources of the different behavior on left and right turns.

[@richlee1374]

@@900BRZ I'm aware of the cylinder stagger in a boxer and noted the differences in the upper pan. Fundamentally, the valvetrain, cylinders and crank and the oil passages in the "upper" portion of th engine should not differ - in a boxer's case left side vs right side (symmetrical apart from the cylinder stagger). So the amount of oil accumulation in the valvetrain area under the same high g-load should more or less be the same. Given the oil pressure test results and the expert's comments, I still think the starvation is caused by the shape of the oil pan and oil pickup tube location. I'm no expert. Just an interested soon to be BRZts owner.

[@02semiata]

Wow great video thanks for all the hard work! I know the video is geared towards the fa24 but I wanted to know if you though overfilling(0.5L) the fa20 would be helpful ? I have logged right hand pressure drops just like you see on the second gen... Thanks

[@KevinWong_BRZ]

From what I understand about teams running the FA20 in endurance racing, an overfill helps. The pressure drop was always an issue in any of the FAxx engines but the FA24 seems to have longer durations at worse minimums.

[@02semiata]

Thanks so much for that very helpful . I will try 6L total at my next track day then.

[@KevinWong_BRZ]

@@02semiata you might want to be careful with a whole liter extra oil because you will have oil in areas not designed for it and have moving parts hit it. As long as you're aware and accepting of the consequences of that, you'll be fine.

[@02semiata]

My understanding is the manual calls for 5.4L during oil change with filter. So a total of 6L would be an extra 0.6(600ml) I think… do I have something wrong here

[@900BRZ]

@@02semiata It’s actually 5.8 qts capacity for the FA20D. Subaru reduced the oil capacity to 5.3 qts in the FA24D for emissions reasons.

[@kjyu]

That's a very interesting discussion, thanks for doing it!

[@subie057]

Good information/video guys. One thought for you. Have you compared the FA20 bottom end/oil pan layout to the FA24's layout? The reason I ask is because I've been reliably running my heavily modified 2014 BRZ at the track for 10+years with a baffled oil pan. By finding the differences between the 2 layouts we might gain some insight to what is causing oil starvation in the FA24.

[@KevinWong_BRZ]

We have actually - we noted the FA20 lower oil pan is slightly larger than the FA24 and the upper oil pan casting is indeed different. The differences aren't drastic but it looks like they made enough changes that its possibly affecting return paths on the right handers even moreso than the first gen. Bear in mind that FA20s had the same oil pressure drops as the FA24 (as noted by 900BRZ in his videos) but the FA24 has them for considerably longer and steeper.

[@maintenancethrottle]

What baffled oil pan are you running? Thx.

[@ck17350]

@DriversPaddock The dead space in the head has actually been addressed on other channels including 900BRZ's. Wish I could remember who's, but one channel 3d printed a part to take up some of the dead space in the head. I don't recall if they had test results on that. Thanks for doing these tests that are more applicable to the average 86/BRZ owner. :)

[@KevinWong_BRZ]

They ATTEMPTED to address it, but hasn't solved it all.

[@Youzsirname]

An excellent and intelligent discussion and very useful advice. Thank you for the great work!

[@brianp1030]

Would I like a oil pan that fixes this issue, sure....but have we seen any oil starvation failures with an Accusump system installed? Serious question, because I don't mind the added complexity and it seems like a reasonable solution.

[@TassieLorenzo]

Great discussion! I'm guessing the GR86/BRZ one-make series will fix this, unless their solution is just to have some spare engines on hand in the series support truck (lol)...? (It's a shame that the official STi baffle ST11109Z2000 for BRZ Cup doesn't work at all.)

[@steve_c1]

For what it’s worth I have a ls3 with a baffled/trapdoor pan that starved in 5b

[@KevinWong_BRZ]

Yes, Vettes have been known to starve there too. Haven't really done any in depth investigation for that engine specifically but how do the baffles look? Horizontal or vertical gates? How is it relative to the pick up?

[@steve_c1]

@@KevinWong_BRZ it’s the sikky pan for ls swap z33 the main issue with ls engines is they don’t have priority oiling to main bearings it’s top down.. aftermarket blocks address this a convo of higher end oil would be a cool video motul vs amsoil etc

[@900BRZ]

LS3 has its own problems for sure. I’ve actually seen as many late model Camero SS engine failures in local track days as I have with FA24s (obviously just anecdotal). My grandfather (small block Chevy engine builder) used to routinely add drainback plumbing from the heads in those engines as well.

[@SolidMGSnake]

Fascinating! Thanks for your expertise on the issue.

[@dillonhoffman9178]

I think we're all just overfilling and waiting for Verus at this point

[@latapx]

@@dillonhoffman9178 heads up, the verus pan is being designed around the OE header...it may not work with any other header.

[@dillonhoffman9178]

@@latapx Yep. Thankfully still OE myself. I have to imagine they will create a version for use with popular aftermarket headers as well considering the target market are people who track their cars, or they will create their own headers that work with the pan.

[@JupiterxBlues]

​@@dillonhoffman9178 the average person who tracks their cars(any car and year, but more so for newer cars) usually keeps their stock exhaust manifolds for track use. After a few track days, that's around the time people usually start swapping manifolds for more power. The people who swap exhaust manifolds on newer cars generally have never seen a track day in their lives and are doing it for the sound more than anything.

[@dillonhoffman9178]

@@JupiterxBlues Considering for this specific platform it's one of the few hardware parts that is proven to provide power I don't think that's true. Plenty of people on this chassis doing a lot of track time replace their headers. I personally have not because the power to me is not worth the price of a header and a tune and I like my car quiet. I see your point, there are a lot of turbo cars nowadays that hardly see a gain in power with aftermarket downpipes but on this specific chassis that is not the case.

[@ruturaj47]

​@@dillonhoffman9178unequal length headers would give much more clearance. Verus oil pan is engineered around stock headers for more oil capacity. If they were designing from scratch without factoring in limitations the shape would have been much different.

[@yipchitaywonga]

around the 27 min mark you ask: " what recommendation do you have for gen2 owners?" does the gen 1 not have that issue as well? (or is it too slow?😛) if not what is the difference and can't the differences be brought to the gen2?

[@KevinWong_BRZ]

Gen 1s are very well established at this point. They also have the same pressure drop as @900brz has documented but nowhere near as long or as steep of a drop. Gen2s made it worse.

[@gamerdaddy2570]

I got 2024 gr86 premium automatic with brembon with 0km. It is my daily. I dont plan to track but ocassional spirited driving. It is under 60,000 km warranty from toyota and i work for the only exslucive dealer in the country. They told me to do oil change every 7500km. My oil changes till 60,000 km is free. What should i do. Keep it or trade it in for supra or honda or anything. This dealer deals wirh multiple brands exclusively so I have options. I am very confused, sometimes i feel its a ticking time bomb. I love the cae though as long as its running fine. Only 1000km done till now. I need serious advise.

[@Flat-Four-Track]

I track at Mosport. I have a 2022 GR running SME turbo kit 350whp that has SME’s extra capacity baffled oil pan. It would be interesting to data log oil pressure with that set up. I overfill and have removed the stock oil cooler, running front mount oil cooler now and also dual Radium oil separators to help with overfill and detonation from oil burning. Running 255 square R compound.

[@KevinWong_BRZ]

If you have a high capacity pan due to the extra space that aftermarket headers can provide, that's likely why you haven't had issues yet.

[@DriversPaddock]

Try logging the pressures the same way we did. Would be interesting data to see.

[@Flat-Four-Track]

@@KevinWong_BRZ yes - it would be interesting to data log and determine if the pan helps to reduce pressure drop.

[@Flat-Four-Track]

@@DriversPaddock agreed, I guess I will try and figure that out.

[@Flat-Four-Track]

@@DriversPaddock kzbin.info/www/bejne/j3fJmWWVaLudiposi=73770EXlPRtPoNLW

[@colinbowman8816]

Do you think Subaru threw a set of 200tw tires on the car and tested it before selling it? What oiling mods are the GR86 cup cars running?

[@KevinWong_BRZ]

Doubt it. The GR86 cup cars seem to be running an oil cooler as well but I have no documentation on the part number from a VERIFIED source.

[@colinbowman8816]

​@@KevinWong_BRZ That's where I'd start. Unless you have a Verus prototype baffle on the way. Might get in contact with a cup car builder, or a team and ask what they're doing to keep motors alive. Seems like windage may be an issue as well: pressure starts out around 100 psi, then it drops to 50 psi quickly after a lap, even when driving straight... oil T is 120C at that point, so it might just be thin oil? Oil cooler experiment might solve that.

[@900BRZ]

@@colinbowman8816 Yes, definitely seems to be either windage or starvation happening on the straights in this video. Close to redline, you see a pressure drop on the straights which recovers after RPM drops after the upshift. I’m thinking windage is more likely than starvation. Rationate for starvation would be increased flow rate due to higher RPM, but with an overfill, I’d assume there would still be enough capacity when there is no meaningful lateral acceleration.

[@2trackminded]

Was the white startup smoke from overfill blow by?

[@KevinWong_BRZ]

We believe it is.

[@briantroy24]

The 1st number does indeed matter, 0W40 will typically break down and thin out before a 5W40, 10W40 etc. The bigger the variance between the winter number and operating temp number matters. I believe the motor oil geek had a video on this.

[@KevinWong_BRZ]

Added to my notes for correction in Part #2! Thanks for contributing to the data!

[@900BRZ]

I watched Lake Speed Jr’s video on this recently and it’s very good: kzbin.info/www/bejne/aF6odHxrqrBsm6c Agree generally, but as a Mobil 1 0W40 FS user, it doesn’t always mean that a 0W is worse than a 5W. In a 15 min KRL test performed in the video above, the Mobil 1 0W40 FS had 10.4% shear (i.e. loss in viscosity @ 100C) while Castrol Edge 5W-40 had 13.6% shear. M1 0W40 also did better in % HTHS shear, with 5.5% vs 7.2%, respectively. The Mobil 1 5W50 they test also has more shear by % than the 0W40 in both tests. That said, there are other formulations which can have much less shear, like the HPL NO VII 5W30 with only 0.6% KRL shear % and 1.1% HTHS shear.

[@KevinWong_BRZ]

​​@@900BRZooooh another member of the STLE (society of tribologists and lubrication engineers). He definitely would know his stuff. Will watch for notes.

[@PocketDrummer]

48:50 - DO NOT USE ADDITIVES!!! You have a lot of good information here, but additives isn't one of them. Best case, they're just an oil thickener, and you'd be better off just buying an oil one grade thicker to begin with. Worst case, it interferes with the additive package that's in your oil, and causes more wear, oxidation, etc. Look up videos from Lake Speed Jr. about this subject. He shows exactly what happens with various additives in a lab. If you want more performance from your oil, use a higher quality oil to begin with.

[@KevinWong_BRZ]

We meant additives that the oil manufacturers already put into their blend not aftermarket DIY ones.

[@ProstoChester]

What has really worked for me. Ive installed aftermarket oil pressure sensor in the block. Ive cleaned all the rtv from oil pickup and installed oil buffle plate. Ive switched to pao ester 5w40 oil, ive constantly overfilling arround 500-600ml of oil. I have no oil cooler or other tuning stuff. Oil pressure stays storng even in hard right turns.

[@KevinWong_BRZ]

Have you done any oil analysis? High pressure due to high viscosity, doesn't necessarily mean more flow. Just gotta remember that.

[@orangetaby6024]

The LIGHTING is backwards,,, can't see anyone's face. The lights should be BEHIND the camera

[@abhimanyupandey9740]

This is prolly one of the major reasons why Toyota is planning on reworking the 86 platform. Using the 1.6 turbo of the GR Corolla with a hybrid set up makes sense as Toyota would have more control over the car and its performance as opposed to being left on the mercy of Subaru and the FA24 platform. The hybrid set up may seem a bit odd. Need to wait out to see how it would perform and feel. OR this could be the last of these cars we may see and Toyota might introduce a coupe type GR Corolla. Would love some discussion on this here. :)

[@patrickbateman7122]

It's a shame (previous gen owner) as the boxer creates that lovely low COG feeling not many cars have which spoils you but i found it such a characterless engine and i got rid of it due to that...

[@abhimanyupandey9740]

@@patrickbateman7122 if you don't mind me asking, characterless how?

[@patrickbateman7122]

@@abhimanyupandey9740 the FA20 felt like it was going to blow up for me at high revs and that torque hole was annoying. I much preferred my 320si E90 (Eu car) 4 pot which genuinely wanted to sing although not as much as a Honda engine i guess..

[@Cichlid_Visuals]

an oil cooler with a positive pressure return line to the oil pan, with a 2 way ball valve to allow drainage (like a fumoto valve) when necessary.

[@artblackwood7936]

The dead space and gravity is a big part of the issue.

[@valkator]

What if you took the lower oil pan and welded flat pieces of steel on a 45-degree angle downwards towards the middle of the pan on each side of the oil pan. If you were to take a hard corner, I don't believe the oil would be able to slosh past that considering it would get trapped in that spot plus there is sort of some kind of downward ramp for the return oil to get to the pan yet.

[@gt4.86]

My GR86 had exact same symptoms about the white smoke. Huge white smoke when start up on the second session. And the car was stock, 0w20 oil with no overfill. What would be your recommendation? Should I be concerned?

[@KevinWong_BRZ]

You might be experiencing something else.

[@alexandram9477]

thank you guys for doing a baseline stock test and presenting it with clarity! For people like myself who daily drive (mine is a 22 BRZ manual), plus once a week do 'spirited' canyon drives (socal), oil temps in 110-115C, should we still overfill and use higher viscosity oil? I love this car and just looking for best practices to keep Uncle Rodney from paying me a visit! I think the incredible chassis/balance/handling kind of belies the the reality that the engine is a cheaply built flat 4, the inherent advantage of gravity is missing (compared to inline or V engines) and because it's cheaply produced it's not really addressing the oil return effectively when pushed hard, especially when modified. I think there's a reason why Subaru's strength in motorsports is in low grip. I like the moody lighting, lol!

[@KevinWong_BRZ]

TLDR? Yes to the 5w30 but the overfill is ... maybe? I highly doubt spirited driving pulls over 1G for as long as @driver's paddock does at this track so you might be ok. You're also spot on about Subaru design inherently being better for low grip as a local Subaru specialist shop tells me... once you go 100% grip driving in Subie engines, they have issues.

[@timster046]

You can run 5w-30 with a half litre overfill with no negatives in this car, unless you have to put up with -20c weather in winter. Subaru dealer near my house, they actually overfilled a little on my last service too.

[@KevinWong_BRZ]

​@@timster046same here lol...

[@johnathanjung7251]

if i also spirted drove during the winter on winter wheels - do u recommend to use OW-20 in the winter?

[@KevinWong_BRZ]

@@johnathanjung7251 I would go with the fill the factory suggests for your temperatures. At that point you're dealing with a completely different set of problems and I highly doubt you're pulling G's in winter conditions.

[@rawrbrz]

Imagine If we could somehow sneak a camera and a light into the block during a session and see how the oil sloshes around. Would be cool to see

[@KevinWong_BRZ]

We honestly thought of this too but it would be coated in oil most of the time making it impossible to see anything.

[@rawrbrz]

@@KevinWong_BRZ derp good point

[@supers0nic77]

My car mr2 spyder with zz engines suffer the same. I did a k24 swap so I'm not sure if it still applies. This video is awesome though.

[@CPE-j1u]

It's so, so, SO interesting that Subaru/Toyota do literally NOTHING about oil starvation AND rtv issues (I just got my tS and did all oils replacement with Motul and Mobil 1 - @1600 KMs)

[@EctoPlasmic]

So if you're just daily driving it (not tracking) should be fine then as you're not pulling those G's on normal traffic.

[@KevinWong_BRZ]

Yeah but I'd still put in 5w30.

[@subiesnacks8446]

Always remember this though as well......people these days tend to make a bigger deal out of things then the problem actually amounts to. But honestly who do you trust? You got manufacturers saying one thing, someone says something else, and then there's always those who hate the car and will just talk negative about it either way. It's very confusing, you almost have to just give'r and see what happens. This platform just need a little more time to be figured out I think.

[@lamesamelame]

These guys are doing what Subaru engineers couldn't do. FN Legends 👍

[@KevinWong_BRZ]

To give credit to Subie engineers and as someone who has worked in that kind of role, I suspect somewhere along the line leadership is saying its not worth the fix at this moment in time. We are talking about the 1% (or less) who will encounter this issue, let alone blow an engine.

[@jamongkad]

@@KevinWong_BRZ I agree, at the end of the day its a bean counter decision and they figured the money spent to fix and warranty the issue is not worth it. Reminds me of the Miata ND transmission issues. Mazda will just keep replacing them under warranty but won’t budge an inch to actually address the issue.

[@lamesamelame]

@@KevinWong_BRZ I wanted to get a BRZ for the track because it was inexpensive... But after reading about the RTV degrading and right turn issues I'm not moving forward. The Miata is too small for my German Shepard... GR Corollas seem to be next best but those have transmission issues: weak 2nd/5th gear and transmission hubs. Types Rs are great just Larger and more expensive; out the door 58k+ USD. 💀💀💀.

[@KevinWong_BRZ]

@@lamesamelame the RTV is a total non issue. You can toss that one out. The oil starvation is only true if you can sustain that kind of lateral G forces for so long. The track we tested it on is one of North America's fastest so unless you plan on putting endless time attack laps at CTMP GP, I'd still recommend the second car with a caveat. I liken it to whether I would recommend a RX8 second gen (before the R3 release). I would but with an asterisk.

[@enricosteinmetz7173]

Could a Dry sump lubrication solve this issue?

[@KevinWong_BRZ]

Absolutely. Except that would be insanely pricey and invasive to install. Needs new headers too. We mention why it's kinda self defeating in the video to produce a dry sump kit or even to buy one if it existed.

[@prs2nd]

for oil cooling, is it possible to make a more effective replacement heat exchanger sandwich plate?

[@KevinWong_BRZ]

For sure. The problem is packaging / manufacturing costs / heat transfer efficiency / pressure drop and mounting. This is why I always feel bad for OEM engineers as they get no respect for doing all of this work.

[@prs2nd]

​@@KevinWong_BRZ i apologize for the speculative follow-up, but do you think a product like this would be viable from a cost/benefit/efficacy standpoint, as direct bolt-on replacement products are the safest mods?

[@ExiledVessel]

So basically, it's a 2d coup sports car that ideally shouldn't be tracked. I really think that subaru should at least update the 2025 model with a bigger pan as that seems like the logical answer to address the concern with minimal cost expense. I don't think you mentioned if the oem part to prevent the crank from getting sloshed on is standard on all gen 2 or what but that should be there too by default. Do you think they should change the recommended oil to a 5w-30 by default regardless of driver use as well as encourage more frequent oil change? If I do decide to buy a BRZ should I be doing more frequent oil changes say every 4k miles instead of the 5-6k that I heard at dealership when looking at a used model? Regardless if the car was tracked or driven spiritedly on canyons?

[@KevinWong_BRZ]

We honestly think unless you add an aftermarket oil cooler, 5w30 isn't enough... you can clearly tell in our video when we hit 130 deg C in only 3 laps around this track.

[@Sherlock535]

Done 2 track days in mine, 0w40 no overfill but I make to sure to short shift on long right hander and back off at 120C oil temp… which basically means only use partial throttle down any straight 😂 Will add an extra 0.5l next time I go out for some more protection.

[@WakeMtz]

The fact that it only happens in right hand turns and not left ones is obvious that is a geometric restriction of the oil pan, pickup tube or timing belt cover. The only other components that are not symmetric would be the oil filter, and the oil pressure valve that could be causing some sort of restiction or release on lateral g forces. If I would go on designing a oil baffle, I would addres the asymetry of the timing belt cover first and then something like a fixed honeycomb arrangement inside the pan to prevent slushing.

[@KevinWong_BRZ]

The oil filter is right on the discharge of the gear pump at the engine so its not a starvation path item. It is literally the first thing TO get oil. The oil pressure relief valve is also on the discharge of the pump and is a necessary item on all positive displacement pumps because catastrophic failure will occur if you deadhead (ie: fully restrict flow via the discharge) a PD pump.

[@WakeMtz]

​@@KevinWong_BRZ I still think is the timing cover the culprit. Even on Subaru's own documents, they mention some "new" ribs inside the cover to prevent this situation, but they never reached production. What I was saying about the release valve is that since it is mounted horizontally, maybe the strong lateral g forces are opening it, causing an oil loop that never reaches the engine. (Very unlikely but possible)

[@KevinWong_BRZ]

@@WakeMtz the relief valve would have to be spring loaded in order not to open at anything other than deadhead pressure for the oil pump. If the spring fails and it opens during any lateral load, it would have opened during the cold start as that's the highest pressure normally. You seen it in the video. The oil is cold and thick and the revs high enough to hit 100+ psi. If the valve isn't cracking open then, it isn't opening on lateral load.

[@WakeMtz]

@@KevinWong_BRZ If those factors are out of the way, then it is obvious the oil is creeping up and getting stuck on the timing belt, there is no other place on the engine that can hold that much oil to leave the sump dry. Maybe the the solution is to fill as much voids in the timing cover as possible and reducing the amount of volume it can hold.

[@KevinWong_BRZ]

@@WakeMtz watch the video lol... We talked about it quite a bit early in the video too. It's not the timing belt but I get where you're trying to go.

[@CarPlebs]

I nearly got a GR86 last week, glad I got a 987.2 CS instead...

[@recca7]

is overfill recommended for daily driving? makes it safer but down on power..?

[@KevinWong_BRZ]

Overfill isn't required for casual daily driving no.

[@recca7]

@KevinWong_BRZ dang it, I already did it😅 but I'm using 0w 20

[@ScottyBeMore]

@@recca7 not required.... but won't hurt anything

[@ronac44]

Accusumps add a lot more extra lines? It’s just one. That’s half of the lines compared to adding an oil cooler…

[@KevinWong_BRZ]

Yes just one acting as both supply and return but depending on where you mount the tank, it might be a lot more distance travelled and thus dP (differential pressure) to and from the tank. dP is the killer here as Subaru likely didn't size the pump for more losses than planned. Ultimately, dP is what matter and not the number of lines. You could run a million small 5mm lines and still have less dP than a sump thats in the trunk.

[@ronac44]

It can be mounted on top of the motor with a 2’ hose which is shorter than a hose going to an oil cooler. They’ve shown to prevent oil pressure from dipping as dramatically with measurements taken at the engine. Saying they add a lot more complexity is just lazy. There’s way more points of failure by adding an oil cooler but nobody bats an eye.

[@KevinWong_BRZ]

@@ronac44 fair point, that's why I held back on the oil cooler but that doesn't take away the points we raised about excessive fill into existing spaces and also how it recharges. Ultimately the Accusump needs time to recharge and that time is time on track - depending on when the next right handers come at you, you MIGHT run into a point of no reserve left. If you increase sump volume, that allows for the OEM equipment to recover better at least with zero added moving parts.

[@geraldjustprojects]

Although accusump may help for a breef period of time. The cooling affect on the oil affecting pressure directly is also a factor to take into account.

[@KevinWong_BRZ]

@@geraldjustprojects extra volume always helps for thermal capacity!

[@johnlu9368]

im stilling think the ts brz or the premium 86

[@xiiimotorsports]

I've got a box of Eneos 0w50 Racing oil for your to test !

[@DriversPaddock]

You know where to find me

[@FendtXerion3800]

I relly enjoy your take on the whole situation. But one part took my really off guard from 25:25 to 26:15. When the resulting acceleration of the engine really reaches 90° you may have other problems than oil starving engines. On 1g side force its an equivalent of 45° force in the reference frame of the car, without taking into account rolling of the car and on a flat surface. When lets say you have 10° roll in the car you have to pull 5.6Gs side force to reach a resulting force vector of 90° in the engine. Without roll 1.5g ist 56.3° and 2g is 63.4°. Adding the body roll angle results in the true force direction. I would really love to see a test with realistic angles to see what really happens in the engine. I mean the concept is right what you tried but the angle ist vastly different from the actual force directions in that car. Maybe when you guys have taken out your engines again you can try this and vary the roll angle to see what is happening. edit: After thinking a bit more about the upper oil pan. I really think you can see the root cause of the right turn problems. The left side of the upper oil pan is more closed and the return lines for the oil seem to be more to the center than on the right side. Which is no problem on 0g side acceleration but with every degree in resulting force angle the left side can hold increasingly more oil than the right side. So i think the return lines on the left are a big contributer to the problem. Maybe there is a difference in dead volume on the left too. I would suspect that adding oil return lines as far to the outside as possible would help.

[@KevinWong_BRZ]

Ding ding ding, give this man a prize.

[@rob_over_9000]

Seems like a new pan is needed. It’s actually insane that Toyota apparently didn’t even test this before releasing it.

[@KevinWong_BRZ]

This failure scenario is literally the 1% or even less for a low volume car. I don't think its a "big enough" issue to warrant the initial test scenarios. As someone who has been involved in product design, you can't test for EVERYTHING so I kinda have some sympathy... but also no. Haha.

[@recca7]

​@KevinWong_BRZ not when this car is advertised as an affordable sports/track car. It should be able withstand what they know these cars are going to be used for. They would've logged in plenty of laps during production, so either they know and decided not to address it or they didn't notice it with their testing equipment. The former is most likely the case, which just really sucks for its fans

[@leom00n79]

Hey all. I plan on getting the 2025 Hakone Edition as a daily driver. Can any owners inform me the long reliability as a daily car?

[@KevinWong_BRZ]

It's fine as a daily driver. No issues. Follow the break in and maintenance and you'll be fine. This video is for the 1% who track and the 1% of that who actually hit high enough lateral G's for enough time.

[@konrad4520]

why didnt they try using 5w=40 oil in there tests if thicker oil is such a important thing, i agree the thicker oil is better but im just wondering why they didnt test 5w-40 then

[@KevinWong_BRZ]

Thicker oil is compensating for the drop off in viscosity as the temperature dials up. It is hurting you on the cold end if that's not your target operating range.

[@zuhlera]

i ordered my brz for a daily commute but not sure if it was a good decision for it

[@jeremyburleson6329]

I love my 2024 GR86 these issues are track related and people drive them on the road extremely hard. There are tons of Facebook groups that GR/BRZ related and they get totaled all the time because how people drive them lol

[@zuhlera]

@@jeremyburleson6329 ahh i see i drive mostly through canyons and PCH to get to work every day , id want to track sometime too but If i ever do id do research first

[@KevinWong_BRZ]

You'll be fine, you're not gonna pull those G's long enough to run it dry.

[@zuhlera]

@@KevinWong_BRZ is it possible to lose pressure even going on a canyon?

[@KevinWong_BRZ]

@@zuhlera it depends if you're pulling enough later G forces long enough.

[@Infinite_AM]

Welcome to the world of boxer engines. Replace your oil pan and your pickup tube. Have a nice day.

[@lenerjan]

How?

[@It_is_about_power]

Did you know, that Toyota will avoid guarantee, if you drove your car higher than 7200rpm?

[@jameshowlett2868]

After discovering these validated issues, I immediately got rid of my GR86 and traded it for a Toyota Corolla. Problem fixed.

[@jeremyburleson6329]

I went from a 2022 SE hatchback 6MT to a 2024 GR86 6MT. Those cars have known issues too lol. Why I sold mine

[@KevinWong_BRZ]

*Doubt*

[@DMA-i8w]

Over reaction

[@Zaratium]

mine blew at 24k miles, and a close friend of mine blew his at 25k miles. all my regularly scheduled maintenance was done in 3k miles intervals by my dealership, and my engine was stock. i was still denied warranty. fuck that

[@oemj7147]

How were you denied warranty? They have to give a reason.

[@Zaratium]

@@oemj7147 they simply stated “for misuse” and that was it. needless to say, i got a lawyer and made sure they never pull that shit on anyone again. it was a successful victory for me at the end

[@KevinWong_BRZ]

@@Zaratium care to post the details of the litigation?

[@Zaratium]

@@KevinWong_BRZ it blew while i was going 57 mph in 3rd gear in midday traffic. had it towed to the dealership immediately, and was told warranty was denied for going 5rpm over the limit thus voiding my warranty

[@rekt4guud134]

There's no way toyota and subaru weren't aware of this problem when they released the car.

[@wolvesbrigade1700]

Verus Engineering Oil Pan Development and maybe a Catch Can System on top of that just got a whole lot more interesting … Also good to learn accusumo which is what I was leaning towards isn’t the best solution.

[@KevinWong_BRZ]

The accusump in my opinion is inelegant and only addresses the symptoms of the problem with a solution that is parasitic in my opinion. Short of redesigning the engine, no solution will be truly root cause fix so our approach will be to dive deeper to the core and resolve it with less parts.

[@wolvesbrigade1700]

@@KevinWong_BRZ agreed, with their already being so many catch cans out there things are looking up imo when combined with ur findings. And I think that oil pan with should increase capacity if I’m not mistaken, hopefully it will be the key. But as mentioned with its design I’m worried about aftermarket header fitment. Regardless the combination of the two seems most appealing while also not causing a significant trade off. With regards the separate RTV issues we are seeing anti-drain out oil adaptations and baffles to help with that as well. So while it’s annoying to have to do all this for the car out the box it’s good to see cost effective solution and more people doing the research to determine what works. But lastly, I wanted to ask if the AOS systems were tested and if they had any different results vs the catch cans?? I’m very curious to see if they are a better option or they same because as I said there many companies making different product in that category that could help.

[@KevinWong_BRZ]

@@wolvesbrigade1700 realistically, AOS vs catch cans have already been argued to death in other discussions and it comes down to what you are willing to live with in your pan. I ran a Radium dual catch can system in my last car (S2000) as I wanted my pan to be as clean as possible with as little fuel in it as I can.

[@wolvesbrigade1700]

@@KevinWong_BRZ expound on the argument and what you mean by “living in your pan” I was always under the impression that the both were equally as effective one just recirculated the fluids while another one didn’t and required emptying out

[@KevinWong_BRZ]

@@wolvesbrigade1700 the catch can was catching moisture, fuel and oil. It wasn't just oil. Everything that blew by was being caught and that stuff wasn't mostly oil. I didn't want thag stuff living in my pan. The AOS is known to return basically everything the catch can captures back to the pan IIRC.

[@Iseenoobpeoples]

If you ran the test again after having done all the alterations that would have been more useful.

[@KevinWong_BRZ]

That's the plan! This test was just the baseline on stock plus 5w30

[@LETerEATRenne]

Toyota really dropped the ball by putting a Subaru power plant in this chassis. Disappointed is an understatement, the new gr86 looks great but that fa24 is junk imo.

[@KevinWong_BRZ]

Its a fine engine just had some really dumb quirks. Even the GR Corollas have engine oil starvation IIRC.

[@1Solace]

Are people still not aware of an oil accumulater?

[@danihan1410]

Subaru needs to fix this problem

[@DriversPaddock]

We may have just fixed it! Check our channel for the latest video!

[@PlayinWithGhosts]

I'm on the fence of Toyota didn't make a track ready 24/7 track car for 30k. If you bought this car thinking you can do that without any additional effort, that's on you.

[@KevinWong_BRZ]

The issue is that the first iteration (FA20) didn't have as bad of an issue as the FA24. So you could say people were somewhat misled.

[@Sam-iw6zl]

Oil starvation when turning to the right at high rev's.... Maybe something to do with the crankshaft throwing more oil to one side of the crankcase/ oil pan than the other?

[@jasonoshima6839]

I wonder how much attention Toyota/Subaru will pay to your findings?

[@KevinWong_BRZ]

Probably next to zero.

[@Reptilianoverlord-jc8mt]

And they advertise it as a track car . What a joke. 😂

[@T_3rR4h]

Just keep it under 6200rpm

[@KevinWong_BRZ]

Kinda kills the point of buying the car when you're capping max tach artificially.

[@christiansprojects-cgmanuf1426]

Dude, learn how to drive stickshift. You are on the gas too early after every upshift, causing the clutch having to compensate for the rev mismatch.

[@Mr_two-v.v]

make a clear oil pan take a video mystery solve

[@KevinWong_BRZ]

Except it'd be coated in oil all the time and make it impossible to see anything in a dynamic situation.

[@FormulaDeltaOG]

There is another channel called Garage 54, where they have done this on a different car/engine, you can take a look at what happens in an inline 4 engine

[@barenekid9695]

Reality is the Subaru Repurposed aircraft Target Drone engine design was NEVER an outstanding design ! Being a DISPOSABLE engine. Decades of add ons hasn't really helped. Notice ? the dozens of hoses to carry half of the Coolant capacity... External.. to the engine. Real answer ? DON"T run a Subaru flat 4.

[@ZONE3965]

So it's a fundamental engine problem and can't easily be fixed... I'm out.

[@1Solace]

Accusump is 500$

[@tone3560]

Just don’t autocross or track it. No oil starvation then.

[@KevinWong_BRZ]

Yeah if you're not gonna be tracking it yep. No issues. Still not convinced autocross can give it that much lateral Gs but testing will prove that.

[@tone3560]

@@KevinWong_BRZ Yeah agreed, I watched most of the track oil pressure drop videos in the right turns and it doesnt start dropping into the dangerous zone unless it is a long sweeping turn at sustained high g's for it to be detrimental. Autocross there is high g's just in very short time frames which it doesn't lose pressure or a miniscule amount that isnt detrimental but cannot 100% confirm that.

[@69fcortina]

Interesting, it appears the OP starts to drop above around 6500 rpm, into the low 50's or even 40's, even without much evidence of lateral g's. Problem wih the pump, or with oil returning to the sump when pushing higher volumes?

[@KevinWong_BRZ]

I know which sections you're referring to - keep in mind that the back straight of GP is an uphill climb with an ever so slight kink right. I don't think I have a pump problem because the oil pressures are rock steady on a flat road.

[@69fcortina]

@@KevinWong_BRZ Thanks. I was just pointing out what I saw. I wasn't thinking it was your pump, but maybe a design problem with the pump and the oiling system as a whole- without knowing or understanding the pump design, I was wondering about cavitation at higher RPM's, or the pump simply pumping oil faster than it can possibly return to the pan- something that has occurred to some people in racing circles. Upgrading a pump can backfire and lead to worse problems. It's more likely that the boxer design has some inherent problems, and oil return needs to be very carefully designed. It seems almost an afterthought in many engines. I've seen enough where major manufacturers had to add restrictions after the fact to some oil galleys because too much oil was being pumped to the top of the engine in too much volume, starving the mains. Looking at that casting of the upper oil pan, it really looks like oil return was a secondary consideration, and I have no idea what accommodations were made to get oil to drain back from the heads or even the ridiculously large timing cover that the engines require. I can imagine oil being held in the front of the engine in prolonged braking, too. It's a real mess- but on the other hand, I have an order in for a BRZ tS, which I never intend to track- I'm too much of an old man. The problem does not seem severe enough to dissuade me from purchasing the car for road use.

[@KevinWong_BRZ]

@@69fcortinaso here's something a lot of people get wrong about cavitation - it happens when the pressure of the fluid at any point within the pump is LOWER than the vapour pressure of the fluid it is pumping, cavitation will occur. Vapour pressure is defined as the pressure which is exerted by that liquid's vapor upon its condensed state to maintain equilibrium. In other words, the pressure where the liquid and its corresponding vapor can happily coexist without one converting to the other. Think of water at atmospheric pressure (101.2kPa). It will happily sit there (assuming no additional heat to evaporate it) forever. If you take the same water to the peak of Mt. Everest (where air pressure is 33.7kPa), the water would start boiling and flash vaporize. This is because you've dropped the vapor pressure and the move towards thermodynamic equilibrium drives the water to flash vaporize. Long story short, unless our OIL is VAPORIZING, it ain't cavitation. Everyone loves to jump on cavitation when they actually mean loss of suction head. The two while occasionally related are not the same thing. Hope I managed to help you understand cavitation! I spent a lot of time dealing with that in the field of pumps.