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

[The Radium King]

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.

[steved0x]

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