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Discussion Starter #1
I have road raced various production and formula cars over the years. All of them had either dry sumps or baffled wet sumps with an Accusump.

Those days are done. I am starting to track my ‘14 BS.

The main difference between track days and road racing is less passing and dicing. Otherwise, they feel pretty similar. Great!

At some g-force in the context of extended track day use, surely a line is crossed where oil starvation commences by subtle degree, if not catastrophically. Flat sixes cannot be immune from this.

The use of a race oil with zinc can partially address this, but zinc eats cats, and race oils do not have the right additive mix for extended road use. Proper protocol for a mixed-use car would dictate multiple flushes of race oil at the track to purge the cats of zinc as soon as possible. Not practical.

Is there a “standard of care” which dictates the use at some point of a baffled sump with the 3.4 flat six? For, instance, when you move from a summer high performance tire to a DOT-race tire? Or is there something in the design of this motor which ameliorates or eliminates this issue? My owner’s manual says essentially that if you use a stickier tire, you may have issues with this. Why would Porsche say that if it were not an issue?
 

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General consensus is that the 9A1 engine is very resistant to oil starvation. It has multiple oil pickups in the pan and is a huge improvement over the previous generation flat 6s from Porsche. I personally have not heard a single account of oiling problems when tracking a 981 - on road or track tires.
 

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Discussion Starter #3 (Edited)
General consensus is that the 9A1 engine is very resistant to oil starvation. It has multiple oil pickups in the pan and is a huge improvement over the previous generation flat 6s from Porsche. I personally have not heard a single account of oiling problems when tracking a 981 - on road or track tires.
Thanks for the response.

I remain curious about this. For instance, what mods would be made to the sump of a 9A1 properly prepped for serious amateur wheel to wheel road racing with PCA or SCCA? Hard to believe that the answer is “none.”

Knowledge about recommended sump mods in that specific context would better define the oil starvation risks when tracking. I’ll look for an answer there and post if I find anything significant.
 

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My understanding is that with the 09 motor scavenge pumps and pickups were added that almost emulate a dry sump. The oil is scavenged from the heads and the sump. So on long high g turns when the oil pools in a head there is a pump to move that oil back into the system avoiding starvation. I think it was referred to as "Semi Dry Sump"??

You might try googling around I cant remember where but I have read several technical articles about the oil systems post 987.1. It is a pretty big issue in the pre 09 cars.

That is interesting that they make that statement in the owners manual
 

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I've been tracking my GT4 for 2 years and have seen very high G forces at Watkins Glen with no issues. I do use Motul 300 V racing oil.
 

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As others have said, this was a common issue for water cooled engines prior the the 9a1 engine. There was good data posted up to 1.5g lateral acceleration with no drop in oil pressure.


Sent from my iPhone using Tapatalk
 

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Discussion Starter #7 (Edited)
Thank you all for the good feedback. I destroyed two high-cost MG race engines due to systemic oiling issues during consecutive race weekends at Blackhawk and Road America in 2016, and in this respect am like a dog too often beaten:waiting with dread for that Sword of Damocles red light to come on.

BillL223, what is your experience with that specific race oil and cat life?
 

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I've been running 300-V about 5 years, 3 in a 987.1 and 2 in a GT4. Both cars are/were street driven but not daily drivers. No cat issues but even so, cats are a lot cheaper than engines. 300-V is a high moly oil.
 

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Discussion Starter #9 (Edited)
I've been running 300-V about 5 years, 3 in a 987.1 and 2 in a GT4. Both cars are/were street driven but not daily drivers. No cat issues but even so, cats are a lot cheaper than engines. 300-V is a high moly oil.
Do you leave that oil in the car, and how often do you change?

Regarding my initial question, I have looked more at how a 9A1 race motor is built. A standard component is a deep sump with more oil capacity—-9.5 to 10 quarts.

This does two things. It permits longer use intervals under stress before the oil overheats, and it extends the run time before oil breaks down and shears out of grade. My full race MG motor had the same kind of enlarged sump, so this is probably SOP for a serious production race motor under race stress.

The problem with getting this wrong in the track day use context is not necessarily catastrophic failure. It is accelerated engine wear. What I am trying to get a feel for is when the stress of track day use approaches or equals race use.

Most road racing is sprints of 20-30 minutes during which the goal is wide open throttle as often as safely possible. Run times are similar to track days usage.

What appears to differ for me, at least, will be time spent at wide open throttle. There is no way that they will be the same, for me at least, on longer straights during track days. There are many other circumstances where wide open throttle will be used, however.

What is hard to assess is at what point a $2500 deep sump and the use of a race oil become prudent measures to achieve reasonable engine
wear rates for track day use.

The problem is not the red light for low oil pressure coming on. It is the more subtle accelerated wear of bearings, cylinder walls and rings caused by compromised lubrication under occasional, at least, extreme stresses in track day usage that surely will approximate race usage for some of us at least some of the time. It all depends on how hard you run.
 

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Brain storming - what about doing a Blackstone or similar oil analysis monthly for a year to get a baseline. Then, with fresh oil do a light DE - say two 20 minute sessions. Send the oil for analysis again and see if any conclusions can be drawn?

If there is no notable wear continue with HPDEs and oil analysis?

If there is some concern based on the results then add high shear oil and repeat and/or add oil cooler or sump.

Where did you see a $2500 sump system for sale for the 9A1s? I have not looked around and I am curious.
 

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Discussion Starter #11 (Edited)
Erik, Bilt Racing, a business partner of LN Engineering and an experienced Cayman race prep shop, makes a bigger race sump for the 9A1. They are a PCA Club Racing national sponsor and know what they are doing. They are just south of Chicago.

My sense is that oil and water temp control are central to this. If you can control those either by how hard you push it or by a bigger sump, additional rad and/or larger oil cooler, you may minimize accelerated wear based on compromised lubrication, although high revs under load will always wear out things much faster than road use even if temps are not high. But extended high revs accompanied by high oil and water temps constitute ”race stress” whether its an SCCA sprint race or a 20 minute track day session, and should mandate race oil.

Generalities aside, it is hard to quantify this. My instinct is to move to a race oil pretty early in the exercise.

I will try to discuss this with Bilt Racing in the next few weeks and post any useful feedback.
 

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I drive hard. I did run a deep sump (Mantis) on my 987.1 as well as the third radiator. Typical oil temp was about 245 going to 255 on a hot summer day. I recommend the 3rd rad. Another issue with these cars is transmission heat. Most racers run a cooler, I did not but did change oil annually using Redline. A LSD makes this worse. I'm trying Motul Gear in the GT4 because of its good viscosity index. A little notchy when cold on the street, good when hot.
 

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Discussion Starter #13 (Edited)
Bill, do you just leave the race oil in the motor between changes or do you flush it after each event?

How many track-hours between changes?

How much street time does the car see?

Have you analyzed your oil ever?

Have you ever had cat issues related to this?

Explain in some detail please.

Last, is your trans a manual or PDK?
 

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I leave the racing oil in the car and change annually. I run 6 DE events a year, this year that was 14 days. I analyze the oil after every change, no issues to date. No CAT issues, manual trans. Drive once or twice a week except during winter bad winter. Back in the day I raced the SCCA National series and qualified for the Run Offs twice. Also former manager of McLaren Engines. My 987.1, which I sold two years ago, has at least 150 track days on it with no engine issues.
 

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Wow 150 track days on a 987.1. I may have to get a cheap one add a radiator and a sump and run this oil. Thats amazing. Pretty sure Bill was running that thing way harder than I ever could.
 

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Discussion Starter #18 (Edited)
I have been thinking about this topic and researching race and high performance oils for the past week. Here are my lay conclusions for what they are worth.

My goal is maximum metal to metal contact protection under high revs and temps, accompanied by no or minimal cat damage. That is the top priority. I don’t care about friction reduction unless in achieving that no other objective sought is compromised. I want a relatively simple protocol that does not involve race oil flushes after each track day.

There is a wealth of misinformation about race oils coming both from oil companies and the internet. The most credible source I have found is an unbiased mechanical engineer who posts at 540ratblog.wordpress.com/.

He scientifically tests various oils and publishes a frequently-updated oil wear protection ranking. In this he expresses wear ratings in psi. The higher the psi number the better.

He also tries to quantify the amount of phosphorus in the tested oils. Phosphorus is what eats cats.

He does not test for friction reduction, which, admittedly, is a positive in an oil intended for track or race use if every fraction of a second counts. It use to count for me when I road raced. I don’t care so much about that for track days.

My search is for the highest psi rating in an oil that does not contain so much phosphorus that it will destroy cats—-anything over about 800 ppm—-and which also contains sufficient levels of “street use” additives to minimize acid formation, carbon deposits, sludge buildup, air bubbles and foam. Also important is a reasonably high thermal breakdown temperature consistent with track day uses in a 981.

To make a long story short, the oil best meeting these parameters I have found is 0W-40 MOBIL 1 FS European Car Formula.

This “street oil’ was ranked number 3 in a very long list of oils tested (including marquee “race oils”) for wear protection under the temp and rev stress that have been discussed in this thread. Thermal breakdown for this oil was noted at 280 degrees, a high number. And at 275 degrees,the wear protection rating was still outstanding as he ranked them—-much higher than many well-known race oils with high levels of ZDDP even at the standard test temp of 230 degrees for those race oils.

Motul 300 tested very well too and was ranked just below this in wear protection rating, but was noted to have too much phosphorus for extended cat life. BillL223, an estimable source for sure, has not experienced this, but the science is against him here. I choose that over anecdotal evidence.

With the parameters expressed above, where I end up on this is to use 0W-40 MOBIL 1 European Car oil and test it periodically after a track day or two to determine quality. I will try to maintain engine oil temp in the 220-230 range—-if necessary, by enlarged sump, third rad or bigger oil cooler or just not pushing it so hard especially on long straights like the front or back straights at Road America.

If I choose to push harder and stress the motor more, this is among the very best oils to do it with.

I encourage anyone interested to read the oil blog referenced above.

If anyone has input on this I would like to hear it. These issues really matter, there are lots of opinions out there, and we all benefit from solid information.
 

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Quick search it looks like 10 qts is ~$80 for the Mobil and $150 for the Motul.

Not ridiculous if you can run it for a year ~ 2 or 3000 track/ street miles.

I think the stuff Jake recommends is about $200 for 10 qts.
 

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Useful information here, glad to see what others are doing. I do have a question for you guys: I try to make it to the track once a month, but I work from home and travel for work so I don't get to drive the car much in between. How often is it recommended to drive the car?
I also have another grocery getter that I use for short trips.
 
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