low oil pressure on the track

[ChrisZang]

I had a great track day @ Infineon yesterday :-)
Well, actually I had to cut it a little short
In session 4 I noticed that even at full RPM the oil pressure gauge was somewhere between 2 and 3 (usually its at 4.5when the RPM are higher than 2k)
Outside temp was 95 degrees and the water temp was at about 220
So I called it a day, let the engine cool down and drove home where everything was back to normal
Could it be that I am using the wrong oil?
I am currently using Mobil 1 15W50

And yes I have an oil pressure gauge in my car:
how you guys like my new view from the driver's seat?

[JFP in PA]

On the track, G forces are the enemy of both your oil and engine. Coming off a corner, the outside cylinder head/cam cover is full of oil, and the oil in the sump is also trying to stand up on the outside wall; your pickup becomes uncovered momentarily, the pressure drops. The oil flooding the outside head will also take some amount of time to drop down to the sump after you are out of the corner loads, so the problem does not instantly go away. Changing oil weight will not help with this, you need better oil control.

Deepening the sump will help to a limited degree, an Accusump system would automatically step in and provide oil until the G forces unload and the oil returns to cover the pickup.

Keeping the oil cooler would also help, as would lowering the coolant temps (third radiator, 160 stat, etc.)

[ChrisZang]

I have a deep oil sump and the phenomenon was consistent al over the track even when I crawled back to the pits
I am thinking about installing an accusump but I don't think it would have made any difference here
What would be the best weight for oil for very hot conditions?

Thanks
Chris

[JFP in PA]

An oil weight for track usage gets into some interesting trade offs; many use 15W-50 or 20W-50, others like 10W-40. Some even change weights for specific track layouts.

You are overlooking the impact of oil "displacement" under repeated high RPM's; just like the G force phenomenon, repeated high RPM usage floods the cam covers with oil faster than the oil can drain back, resulting in low oil levels in the sump. This is even a problem on drag cars, where with out specific modifications, more than 85% or the oil capacity can be up in the top of the engine by second gear, starving the pump. This is one of the reasons Porsche created the “X51” option with additional scavenging pumps in the heads and a “northwest passage” oil return that by-passes the engine and routes the oil directly back to the sump. There are also aftermarket kits that do much the same as the X51 package, but they are very expensive and require removal, drilling, and sometimes welding on the cam covers; so they are not for the “faint of heart” due to the fact that your cam covers a machine matched to your heads and cannot be replaced if screwed up.

Oil control is a lot more than just weight selection; it is knowing where the oil is, and where you want it to be........

[ChrisZang]

Hi,
Summary of the old thread with updates, so here it goes:

Since I upgraded my instrument cluster to a 996 cluster and installed the 996 oil pressure sensor, I have now more insight into the inner workings of my car

On my last two track events I noticed the following:
Sometime in the middle of session 3 or 4 the oil pressure starts to drop to around 1.5 bar (approx 20+ psi) no matter what the RPM. This has nothing to do with high G-forces during hard cornering as I usually notice the symptom at full open throttle on the straights (where else can you peek down to check the gauges?)

At the same time I noticed that the coolant temp went up to around 230 F

So I initially thought it must be an issue with the cooling system
So here's what I did:
* Replaced water pump
* installed LN engineering low-temp thermostat
* cleaned the radiators (also cleaned between the radiators and the AC condensers)
* switched from 15W50 to 10W40
* bled the coolant system twice
* checked that all the electric fans kick in
* checked pressure on the coolant lines to the front radiators

My next (and last track day of this season) is coming up this Sunday
For some reason I am worried that I will be running into the same issues again.

In case it happens again I wanted to measure the oil temp via the Durametric right after I pull off the track, to see if the oil gets too hot (I have an "S", so I have the larger oil cooler already).


So, here's the question(s):
* Is it possible that the only issue is that the oil pressure sensor itself is malfunctioning
* Anything else I can do/check ?

[onaFLYer]

I had a similar experience last month at Reno-Fernley SCCA trackday. It ended up with my car on a flatbed, after going into "limp mode" and the low oil light flashing. Now has a significant rattle noise. Not good. Haven't determined the exact failure yet, could be a spun bearing or my new IMS has failed already.

[ChrisZang]

Originally Posted by onaFLYer

I had a similar experience last month at Reno-Fernley SCCA trackday. It ended up with my car on a flatbed, after going into "limp mode" and the low oil light flashing. Now has a significant rattle noise. Not good. Haven't determined the exact failure yet, could be a spun bearing or my new IMS has failed already.

Well, that is certainly encouraging

[onaFLYer]

a quick shot of metal flakes in my filter housing.

[skistewart]

If you are still having problems talk to the guys at 5th Gear motorsports in Dallas, as for Rick Sr.
972 317 4005. They do race support out here and have solved similar issues for the 944 with a baffled modified oil pan
Jim

[thstone]

Read more about oil starvation in this thread... Oil Starvation

[gschotland]

A couple of weeks ago I went to a NNJ Region PCA Boxster/Cayman tech session at PowerTech in Rockaway, NJ. One of the shop owners spoke at length about this oil sump extension kit that's very effective at dealing with oil starvation:

Mantis Sport > Products

One of PowerTech's owners has this on his Cayman S and loves it, and they have a number of customers who are serious racers that have found this kit to be very effective. I'm no expert, but it seems to be a proven, cost effective solution.

[jaykay]

I just put it on .... A beautiful piece. I will let you know how things go. I hate to say but I have no oil pressure indication yet....it's making me crazy

[thstone]

The Mantis product is several hundred $$ more expensive than the Porsche X-51 solution. See the other oil starvation thread for the entire discussion...

[ChrisZang]

just to re-iterate:
I have the LN Engineering deep sump, which should help with oil starvation in high g-forces (I think the other thread is very informative about this), but the deep sump has no impact at all on the issue I am experiencing which is general drop in oil pressure when the engine gets really hot

[MileHighBoxster]

It's not your weight. It's your lateral g-forces acting against you. Go with a deep-sump system and you'll be golden.

[ChrisZang]

Originally Posted by MileHighBoxster

It's not your weight. It's your lateral g-forces acting against you. Go with a deep-sump system and you'll be golden.

I HAVE a deep sump system

[MileHighBoxster]

Then I too would say - Accusump. But I see you're covering this on the other thread, so you already know this. Disregard.

[jaykay]

Chris

Look into whether there is a way to tell if your oil cooler is functioning as it should. I have heard of problems ...rarely though

You may have to play with the oil you are using

Redline water wetter may give you additional cooling assuming your cooling system is working properly...I have it in my car

I think you have the low temp thermostat already

Change or verify that your oil pressure transducer is giving you the right information....what did you do to get it shown in your car?