Racers. Do you worry about oiling issues, or do you just drive?
 

I'm in two minds about how to approach this.

From time to time I get sucked in by the black hole on the Internet that goes on about oiling issues and imminent engine implosion. And despite my efforts to improve the oil supply I feel I own a ticking time bomb and want to get rid of it.

Often times, however, I figure I should just stop worrying, do the regular service, drive as hard as I can on track and trust that things will most likely hold up for a long time as long as I take care of them.

PS: UPDATED QUESTIONS DUE TO THE FIRST ONES BEING UNCLEAR! (See post #5)
1 Do you active racers often experience engine failueres?
2. Do you active racers often see other racers who have engine failueres?
3. Do you active racers constantly fear engine failueres, and does it influence the way you enjoy the car?

Search, plenty threads about this problem

I'm a firm believer in that you make you own luck:) I will do the things that give me peace of mind (within reason and budget), and for the rest, just enjoy!

Obviously, I would do the IMS bearing upgrade first, but M96-97 engines have some pretty serious issues with engine oil starvation if you push them hard... start with the right oil, oil quantity, oil filter, oil sump baffles, maybe a deep sump and an Accusump. There are other more expensive things you can do like dual scavenge pumps, and even a dry sump upgrade (if you have the money or skills). Oil pressure and temperature gauges will help some, but a real data logger would be best since your focus on the track should be outside not inside.

It all depends on your driving skill level, what you want to do with your car (track only or track/daily driver), and off course your budget.

I use a 2 qt deep sump with horizontal baffle combined with a X51 style vertical baffle.

http://986forum.com/forums/uploads02...1508302197.jpg

I guess my question was unclear. I'm sorry!

I've been reading all about this for years.

My engine has:
Deep sump
Horizontal baffle plate
Original vertical baffle
Original swirl pots
Large heat exchanger
3.2L coolant pipes
Central rad.
Original dual row IMS inspected and in great shape.

Internet is a dificult place to find objective information, and few of us are willing to do destructive testing, or have the datalogs needed to find out if our mods work or not.

All my mods are based on the best knowledge available at the time, but cruisually not backed up by actual data on oil pressures during a race, at least not data made available to the public.

Oil pressure drops seem to be a problem.
The only info I've seen on this that's backed up by actual available data says that:
Deep sump doesn't work.
Accusump doesn't work
Baffles doesn't work
Dry sump works. (but what about IMS splash lubrication? Pressure feed?)

I was planning to add an accusump to the system, but since the only data I'v seen says it doesn't help I've decided to drop it.

I am the only one I know who's building a 2.5 racer in the country so I have absolutely no real-life info to draw on. Only forums and vendors. Hence my questions

What I'm getting at is this: As almost none of you have dry sumps and you are still racing: If they constantly blow up there would be no racing.

How frequent are actual engine blow ups during races?

Do you worry that the engine is weak and will blow, and does it hold you back from enjoying the car and going for it in races and during practice?

Or is this actually as solid an engine as other street engines tthat are raced?

I've had nothing but bad luck with the engines in my 944 T which has run for a total of 6 months during 8 years ownership. If the m96 is as bad as the Internet says I'd rather drop this project, buy a new shell, return her to stock. That way I can cut my losses and buy a Ginetta with a rock solid crate Ford engine., But the mixed Porsche racing we have seems so fun....

Thanks for your detailed reply. Do you have any datalogs you might share?
I will be running a datalogger, but I have no logs yet.

I want to keep driving as hard as I can on the best suspension and tyres I can afford. It is a stripped, fully caged race car build. I'm also allowed aero changes such as a real splitter and rear wing.

Looks very nice and extremely similar to my setup.

Have you done any datalogging of oil pressure with this installed?

I run my 2002 in track days, and use street tires to keep the g-loads low because of the oiling problems. I also have a sandwich plate which lowers the sump, along with the plate to also lower the oil pickup. While I had it apart, I went ahead and installed the X51 baffle as well.

No, I have not done any data logging.

Nice! Sounds like yours is holding up fine.
How many track days per year? Would you say that fear of an engine failure is the main reason you avoid running at a higher speed potential (sticky tires)? Or are there other considerations you consider important?

OK. Thanks for replying. How many track hours have you done with it? I've done about 10h. with my similar sump but temps are likely much cooler here.

from what i can glean, engines fail from extended g-force in one direction (depending on the car - different in rear vs mid-engined applications?). g-force due to sticky tires and/or long/banked turns.

it is not a pick-up, oil capacity or foaming problem, otherwise updated pickups, extended sumps, baffles, and accusumps would address.

it appears to be an oil pooling in the heads problem. indirect evidence? x51 and subsequent generation engines add additional head scavenge pumps. now, the oil pooling in the head reduces available oil, however as noted, increasing oil capacity doesn't solve the problem, so the issue is that the oil doesn't move once in the head in these high-g conditions, so doesn't cool and eventually breaks down and something fails.

so, there are additional scavenge pumps you can add (TTP sells a kit) or you can get a dry sump kit. the benefits of the dry sump noted below are not the increased capacity or the increased defoaming, but rather that the external scavenge pump draws from the heads as well as the sump. you note that an aos is not required with his kit - this is because *i think* he is using the aos vents on the heads to scavenge from (and also starts you down the thought path of how oil pooling in the heads is also tied to aos failures on the track ...).

i have a further sneaking suspicion, however. jake raby notes that his is not that impressed with the x51 heads, which leads me do believe that the additional scavenging in the heads is not the silver bullet. also noting that oiling failures do not all occur in the heads; they are also seen in the bottom end. what i am thinking is that oil pooling in the heads is creating sufficient back-pressure to trigger the spring-loaded pressure relief valve in the oil pump and, as a result, inhibiting oiling throughout the engine in extended high-g situations. my question would be if anyone has put a different spring in that thing - how does oil pressure behave at the track?

ps, this doesn't answer your question at all, but the thread got me thinking out loud so to speak.

I have worried about this issue in the past and tried different things and where I am currently:

• LN 2 QT Deep sump with X-51 style baffle for oil starvation issues
• UD crank pulley for power steering pump longevity
• Low temp thermostat
• Double row LN ceramic IMS retrofit
• 10W50 oil
• Oil temp and oil pressure gauges to monitor things
• Switch that runs both rad fans on high
• I am back to running my oil level 1 bar down from full on the digital gauge (I used to run down around 1/2 to 1/3 from the bottom bar). I haven't been having any AOS trouble but that may be track dependent.

I feel pretty good with this setup, running on 100 TW r-comps like Nitto NT-01 or Maxxis RC-1 and 200TW tires like Hankook R-S3.

I don't have any data logging but I do have a camera setup that captures the oil gauges so it is like a "poor-man's" data logging.

The 10W50 (I am running Miller$ nano 10W50) - the 50 part helps and yields better results and less dips than the 5W40 especially when hot - Mobil 1 5W50 is an alternative an on the Porsche approved list or Amsoil 15W50. I like the Millers because I can get 5000+ miles on each fill (mostly HPDE and to/from the track driving) and still get a good UOA with plenty of TBN left. The longer life helps mitigate the cost for me.

I still get dips in places, but they are not severe and my UOA are good and not showing any abnormal wear, so I am feeling pretty good.

Ultimately I would like to go dry sump, but it is $$$. :) Cheaper than a 996TT though or an air cooled dry sump 911. And I really like the Boxster platform.

Future potential reliability mods - replace the OEM rad fans with SPAL fans to see if I can keep things a little cooler, maybe combined with new radiators.

A counterpoint - the guy I bought my tire trailer from traded in his 986 Boxster after 80,000+ street miles and many years of track days, with his only mod being lowering springs and r-comp tires (and he was fast, 4+ seconds faster than me at Roebling) had no trouble whatsoever and his car was still in great condition when he traded it in on a new Cayman...

Steve

Could you point us tho the data?

Nice info people. Keep it coming.

As far as sources, the only available info based on datalogging I have found comes from Chris Cervelli in this thread:
https://rennlist.com/forums/racing-and-drivers-education-forum/981880-boxster-dry-sump-system.html
Please read the thread as I don't want to quote too much of his work. However, here are some key findings.

Others might not agree with his findings, but until data is available which proves otherwise this is the information I choose to go with. Based on his logs he states that:

I have a hand built by me Frankenstein motor there is very little left that has not seen some modification. I currently have 40k on the motor rebuild. I don't think about it too much at the track. I do watch my videos and data logs carefully when I get home. I have 2 oil pressure gauges and an oil temp gauge, that I can watch on track, but don't watch more than a glance or so a lap. I run Dot 40 CAA or BAA Slick tires. I will see G's in the 1.6, 1.8 range on really good laps. I have added measures as the G's have increased through the years. My oiling, cooling mods go like this

1. Dual chamber AOS (motorsport AOS)
2. LN ceramic IMS bearing.
3. LN 1/2 Qt Deep Sump. with X51 stainless baffle.
4. Third radiator
5. 4" underdrive pulley
6. Accusump. 2 Qt. with remote filter.
7. 997 oil cooler.
8. Air to Oil cooler fan cooled.
9. Electric power steering pump.
10. Manual engine Bay Fan switch.

tldr:
Just drive.

1 Do you active racers often experience engine failueres?
no

2. Do you active racers often see other racers who have engine failueres?
no

3. Do you active racers constantly fear engine failueres, and does it influence the way you enjoy the car?
no

I admire what Chris Cervelli is doing for the dry sump solution, and I had read that post. The problem is that he does not say what the issue is, only somewhat vague statements on how some common fixes don't help, namely, Accusump, extended oil sumps, oil baffles and Dual scavenge pumps. No doubt the ultimate solution IS Dry Sump, but, to what the Radium King said, why did the X51 and all subsequent engines have an additional oil scavenging pump if that is not at least part of the issue? Also, how can an Accusump NOT help, even if oil is pooling in the heads? Accusump also adds a couple quarts of oil to the system, so that certainly helps to keep temps down. So, short of spending $20K on a dry sump system, I'll go with the "band aids" for now:D

Hey Jsceash, did you notice coolant and/or oil temps lower after you installed the 997 cooler?

I did five track days last year, but only one this year. :(

There are two reasons I haven't gone to R-compound tires - I wanted to avoid the oil starvation trouble, and the cost. I'd have to get another set of wheels + the cost of the tires themselves.

What track do you run at in Norway?

I'm with you and your thoughts mirror the reasons I started the thread. I'm also with you on the cost issue, but if you follow the cost argument further...what if the most important factor is driving style and the band aids actually do nothing to stabelize oil pressure and are purely there for as a comfort blanket and to fill vendor's pockets? If so we might as well just stop after doing all cooling mods (confirmed) and just drive...We keep the money for a future rebulid. Unless the mods add power of course.

The reason I'm sceptical to the accusump is that I have read, and I suspect, it simply has too much lag to fill in the pressure dips. Also, all air bubble sucked in by the pickup, (or from pump cavitation due to high RPMs?)is already in the systen when the pressure drops and the only way to purge it is via the bearings. As Chris says it may help for extreme cases where the pickup continues to suck air for a longer period, but that is not what is causing pressure dips. If you have lost pressure for that long you have also lost your engine, in my opinion.

When it comes to the dual scavenge pumps they may be needed for other issues.In more powerful high-revving engines where the oil flow is higher. Pooling, backpressure and areation from the moving valve train come to mind. Anyway, they surely can't hurt our engine.

Chris states that the X51 baffles may work in the rear mounted 911s, but if the logs show the same pressure dips as before the installation in a mid-mounted engine it clearly does not alleviate the specific problem of pressure drop spikes in our cars, at least not in the tested engine.

I understand your reasoning. Thanks.
I mainly run at Rudskogen. It is mostely accelerating rights and stop-go lefts. One of the rights is high speed and severely off camber. Top speed braking while turning right down the steep hill, then hard acceleration back up the hill and into the S's. This is where I expect the problem to be worst.

Nice mods and longevity.
Did you alter bearing clearances?
Would you mind sharing some of your logs?

Just to add my two cents.
80% of my business is to the racing crowd. I spend a lot of time talking to these guys and a lot of them are removing the accusump system because it isn't reliable (pressure switch)and is just dead weight. Of course you also have a bunch of people who swear by them. I'm leaning towards the useless side even though I have one in my car. I do like the ability to pre-lube though. That's when it's working at least. One thing they all agree on is the baffling in the oil pan. I think they all either use the X51, aftermarket or modify a factory pan.
Now when it comes to Cervelli's drysump system. It looks to be a wonderful system and has proven itself on the race track. Chris races in WRL and I don't believe he's blown a motor since installing his system. For those who don't know. Guys race for 8-24 hours in the WRL series. They beat the living tar out of these cars and 100 hours seems to be how long a motor last with them. Except Chris! Other race teams who compete with Chris are installing his system. It's not cheap but it might pay off in the long run. Here's the his website boxsterdrysump.wordpress.com or you can call him at 303-809-6173

Thanks for your opinion Woody. That's the final nail in the coffin for the accusump as far as I'm concerned. I have spoken to Chris, but I need to prioritize building a workshop. Maybe I'll buy his system in the not too distant future. In the meantime I hope my engine doesn't blow :D

Last summer I was hitting 205 on a regular basis. The track outings this year I saw my water temp at 185 to 190. My oil pressure was stable with a 15 PSI drop at 1.4 and 1.6 G's on the passenger side head, and no drop on the sump.

On a side note I added the engine bay switch at the same time so it is hard to say how much each helped.

My crank was balanced by a local service that builds 410 sprint engines. It was installed with stock Porsche bearings. My spinning weight is over 10 pounds less than stock.

I have shared videos with data on them but I don't know how to extract the data out of the video. I use a Garmin Virb XE with a Blu-tooth ODBII.

I don't know anything about the dry sump. The solenoid supplied with the accusump is crap, if you have one get rid of it. Find a online supplier of a 1/4 SS solenoid with a edpm diaphragm. Or else buy the manual operating kit.

My 2.5L Boxster logged 100+ track days, many at ACS Fontana which is known to kill dozens of 986 motors directly due to starvation. My brother and I ran nearly identical cars and both were regularly at the pointy end of the BSX time sheet. We never killed a motor.


There are lots of gizmos, gadgets, and methods to attempt to resolve this and I don't know any that are 100% effective. Here was our strategy with success over nearly 200 combined track days:

-Run NT-01 tires which are good track tires but generate less lateral G forces than the 40tw R-Comps.

- X-51 pan

- Castrol 5w40 oil changed every 6 months

- Make sure the oil level was exactly topped before every session at hi G tracks.

- Complete the banked sweeper at max speed and stay well away from the rev limit as we downshift for the next corner. The idea here is that after a banked sweeper, the pan is nearly dry from hi G cornering so we let the car idle under full braking to allow for some refill and only blip to 4k on downshift at the last possible moment. Pinging the rev limit with a nearly empty oil pan is the best way to cavitate the oil pickup and score the main bearings, killing a nice flat six motor.

I can't say these methods will work for everyone but they certainly were effective for us in BSX class.

I didn't say in my post above, I almost never go above 6500 RPM and typically shift around 6000-6200, exceptions are places like coming up to tower turn at Sebring (or other turns) where I don't really have time upshift because I would then immediately downshift so I wind it out a little but try never to go above 6500. I believe 6500 is the Rev limit on the 2.5 engine as well. It's just my philosophy. Am I losing time? Maybe... :)

Steve. What you are saying makes a lot of sense and is very interesting. Changing driving style and remaining quick may be the most efficient (and most complex) mod there is. I'll have to study a map of your track to learn more.

Unfortunately, a better solenoid won't help purge air that has already entered the pickup, which is what a pressure drop spike is. The air, or lack of oil, still has to pass by the bearings.

Hey Thstone, what brand is the horizontal baffle you have? Is it the LN Engineering one?

not to answer for him, but thats the TuneRS one, also known as Pedro's techno sump.

Yeah, then he added on the EBS X-51 baffle - more details in his thread (it is a big thread and many pictures are gone unfortunately due to photobucket...)

http://986forum.com/forums/boxster-racing-forum/46070-spec-boxster-build.html

I’ve been tracking my car (VIR) with R compounds for years and in addition to track events have been completing up to 20 autocrosses/year. It’s been living this life for 7 years or so, with no extra cooling or oil modifications (stock cooler, stock baffle etc) and I’ve been running Mobil one (not the best). It’s never had a problem, it’s outlived most of my buddy’s non-Porsche engines. I don’t have any “tricks” I redline it, don’t pay any mind to long sweepers and don’t have any oil gauges. VIR doesn’t have any banked corners per day but the car does pull 1.28 Gs in hog pen due to the elevation change. This all being said it’s probably on fire as we speak...better go check on it

@truegearhead. I suspect a lot of people do this and get away with it. People tend to talk about what goes wrong. If something works as expected they generally keep quiet, and nobody makes money on solutions that way either. Thanks. Then again, maybe your driving style is better for the engine. My plan for next season is to follow your example, with the exception that I do have some mods in place.

Just for kicks. Here's a nice rendering showing tank sloshing and the effect of baffles.

The rendering is of course not directly comparable to an engine as it does not take the insane tornado of windage and the unbelievably rapid flow of oil into account.

Considering the pickup would be in the middle it seems clear that baffle higth is important. The effect of the baffles depend on enough oil being returned to the central space as it is sucked dry by the pickup. At high RPM the oil pump moves about 1 qt (0.9L) pr. second or more. The amount of oil that can be returned at speed into the central space, and how aereated it is, becomes just as important, if not more, than how well the baffles can retain the oil.

Another potential problem could be that it seems like large pockets of air may be introduced as the oil rushes back to fill the empty side of the tank. This may be why some report more spiking in oil pressure with baffles.

Oil flow numbers.
964 - 65L per minute
930 3.3L - 100L per minute (high performance engines from this era uses larger bearing clearances to aid cooling, amongst other things. They need a higher weigth oil and larger flow to maintain the same pressure.
GT3 RS - 83L per minute (clearances are tighter in modern engines so a lower weight oil may be used. This lowers the need for flow and increases efficiency)
3.8 RSR - 57L per minute based on one persons dyno testing.
Source: http://forums.pelicanparts.com/porsche-911-technical-forum/193700-oil-pump-rating.html

Accusumps work great if you use the electric or manual valves. It's just 2 or 3 quarts of pressurized oil always available to feed the main bearings, pressurized by the oil pump. No lag, just pressurized oil. Stay away from the EPC set up where there is a pressure sensor that operates the solenoid...these have proven to be unreliable and can not deal with the wide range of oil pressures one sees on the track. The down side on this style is you need to remember to fill it EVERYTIME you turn the motor off and do it the same way each time so you can get consistent oil level readings.

So if I were to bypass the pressure switch that activates the EPC solenoid valve and just have a switch to turn it ON/OFF, would that work as well as the Electric Valve? I could easily test that just by some minor rewiring work, without physically removing the pressure switch. I like the EPC valve because it is a one-way valve and fills up the tank when turned off. I'm currently setting up my Race Capture and AnalogX system and hope to have oil pressure data at 2 locations: the standard bank 1 valve cover location, and also at the inlet of the remote oil filter (before the filter/cooler, after the oil pump). That is just across from where the Accusump feeds into the circuit (at the outlet of the remote oil filter). This should give me info on oil pump outlet pressure, and total pressure drop across the filter, cooler and engine bearings.