Hella-Buggin'

I think that's Thunderhill actually.

Here's a video of someone else having the same issue. It's a pretty known problem. I wish I knew for sure how serious of an issue and a sure fire cure but I don't. If you find something out, let me know for sure.

Slakker

FYI, DT40 is not meant for the track. It caps out at 240F. XP9 is a great track oil but it's not meant to do much more than 750 miles.

SWK6Cup

fair question, will have to check my paperwork file and see if I can get you an answer.

Hella-Buggin'

Interesting. Their website claim highetbshear for night temp situations. Where are you getting that data? I've emailed back and forth with them and they recommended DT40 & FR50 for my intended use.

NürburgringOrBst

I was having trouble in the same turns as in the video, but for me the drop in pressure was more pronounced. I was pushing the car through the turns quite a bit harder than that guy though.

Also for what it's worth, I'm using Amsoil 5w-40 (40 hot because it's going to be winter time here) and Judd at Flat 6 innovations said that was a great choice for DE.

I still am having a hard time believe that the drop in the gauge is somehow a faulty sender or a passage that is too small to the sender. The gauge's characteristics are consistent with other cars depending on the operating temps and rpms, and also pressure doens't care how small the passage is unless fluid flow is involved.

Can a durametric log oil pressure and oil temp? Maybe I could put a small tablet in the car while hooked up with that software next time (I don't own durametric yet).

NürburgringOrBst

Just in case anyone is wondering, I noticed this problem on the first session out (paranoid from all the threads I read on here!). After that, I went slower around right hand turns and used the next taller gear to keep the RPM below 4K when the needle would start to show 2-3 bar.

Hella-Buggin'

I'm not sure if Durametric logs Oil Pressure info. That data might need to be tapped from the CAN buss. I noticed this drop in pressure not only in right banked turns but also in steep uphill pulls to a lesser degree. I wasn't suggesting that the sensor is faulty but rather it's design may reflect a small pressure drop inaccurately. I notice no pressure drop on left hand turns and since the oil pickup is centrally located I don't think sucking air is the issue or it would show up in left turns as well. At Thunderhill, on T2 I'm banking left and carrying a sustained load of over 1G with no drop in pressure according to the dash gauge yet coming out of the cyclone I'm not carrying that amount of G Load yet the pressure drops and holds at 2.5 Bar despite RMP's.

NürburgringOrBst

That's a great point about the pickup. As I studied the OEM oil pan a bit more, I tend to agree with you. The pickup is centrally located....even if more oil was returning on one side of the pan it would quickly normalize as the oil slips past the baffle.

Yet the oil pressure sender is on one side of the engine, isn't it? Maybe it is time to get a real gauge or data logging to see if this is a real issue or not for cars on street tires.

d15b7

question for you guys -- how quickly does the stock oil pressure gauge respond? by that, I mean - is it 'damped'? most electric factory gauges are pretty well damped; they are designed to move fairly slowly (for example, if the oil pressure were at 60 psi and suddenly the pickup was uncovered, it might take 2 secs for most electric factory oil pressure gauges to drop totally to zero (at least in my experience)). for my racecars I typically use mechanical autometer pressure gauges that are not liquid filled; with hot oil, the oil pressure will clearly full sweep from 60 psi to 0 psi in about 1/2 sec or less. when I was having issues with oil pressure on my Lotus Super Seven (and eventually accusumped it) I'd point a gopro at the oil pressure gauge and it would literally flick from 60 to 0 practically instantly, and then flick from 0 to 60 again when the pickup was covered with oil again. this was horrifying to watch!!! now with the accusump, it falls slowly over a period of 1-2 secs to maybe 30-35 psi and then suddenly flicks back up to 60 psi.

I wonder if the Porsche electric gauge is damped, and that in reality maybe the oil pressure is 0, but the gauge is in the process of sweeping down and never gets the chance to show 0 because oil pressure returns once the pickup is covered in oil again and then sweeps back up to 60 again (but never shows less than 30 on the gauge due to the damping).

testing this would be easy -- install an undamped mechanical gauge in place of the factory gauge and watch it's behavior (gopro is super helpful for this)

Hella-Buggin'

The dash Oil Pressure gauge is dampened for sure. It basically responds like so...

Let's say I'm entering a right handed sweeper at 4k rpm, my pressure gauge would read about 4.5 Bar. As I turn in and the G force increases, the gauge slowly dips down and holds at 2.5 Bar. As I unwind and accelerate, it climbs back up to normal. Now, it doesn't do this on a left sweeper at all and holds rock solid at 4.5 Bar the entire time.

Now, 2.5 Bar = 36 PSI so I've been told it's not a huge issue but it is troubling.

I'd love to install a more accurate monitoring system and plan on discussing it with my mechanic but as of yet I haven't heard any good solutions.

An Accusump would fill the void in pressure until it's sump canister was empty. Not sure how long it would last supplementing a constsnt draw like that.

-Mark

jdistefa

Truth is that the M96 motor is sh*t for this application and needs a dry sump system or at least better oil scavenging pickups and pumps. Everything we do with deeper wet sumps, baffles, windage trays, cooling, and oil selection are bandaids to compensate for a flawed design.

NürburgringOrBst

Mark,

I think by dampened he means how quickly the gauge is responding compared to actual oil pressure.

My take is that the 996 gauge is damped a bit. I have definitely seen much worse (Japanese cars) where the gauge response is so slow by the time it is indicating low oil pressure it could be too late. What's the point then??

Before I went out on track I blipped the throttle to see how quickly the oil pressure gauge responds. Compared to my race car with an immediately responding gauge, I felt comfortable with the 996 gauge in how fast it responds. Just FYI, an un-dampened gauge will respond almost like a tachometer in how fast the pressure rises with RPM.

SWK6Cup

Did the research- using a deep sump conversion, LN x51 pan with baffle mod.

Slakker

That's what I was told by Jake Raby of FSI who helped develop DT40. I use it in my DD and it seems to work really well.

NYoutftr

If I install a X51 oil pan, will the factory Porsche skidplate still attach properly?