kondata17

I'll preface this thread with lots of searching done on my end. My car is a 99 996 coupe. Engine is mainly stock, 200utqg tires, some suspension work, 99% street car. What I have done is installed a 1.5L Mantis oil pan with baffles, set up a front mounted oil cooler (with a Tilton pump running lines from the pan), upgraded radiators and new cooling system.

I've ran the car at one track day completely stock and noticed oil pressure dipping to 1-2bar in high G turns. installed the mantis pan, oil cooler and took it back out again only to find the same results.

I see plenty of people running their cars at the track so I'm assuming either you guys live with pressure drop and roll the dice or do something different from me (perhaps an accusump?)

this is my 3rd track day in the 996 with same results no matter what oiling mods I do so any input is appreciated.

Kris Murphy

I have been chasing the problem all season. My car will be fine for the first 15 minutes of the first session of the day, and progressively give me less and less time as the day progresses. By the end of the day, I am only out on the track for about 8 minutes until it starts to drop, at which point I pit in (I blew my motor last year, 100% my fault), so I am very cautious when it comes to things that could blow it up again.

I have the FVD deep sump and run XP9 oil. I have done all of the same research as you have, and have not found the magic bullet to fix the issue. Not everyone has the issue. I know someone that just started using XP9 and it fixed the issue. Others have used accusumps and it still does not fix the issue.

I have also seen multiple videos of people who have been tracking their car for thousands of miles and in every turn you see it dip.

What is interesting is that the motor I have is a remanufactured motor by Porsche with all of the 997 upgrades. This issue started after I put this motor in. It never happened on the original motor before I blew it up. Do you know if you have the original motor in your car?

Part of me suspects it is actually an issue with the oil pressure sending unit (which I did replace). I may add a new oil pressure gauge and see if it is really an issue. I was planning on getting the mantis pan, but since that did not help you, maybe I will not bother.

Sorry, this is not giving you any answers, but it is giving some additional data.

Slakker

To ask the obvious question, if you are at full throttle does it do the same thing. The answer to all questions on the track is more gas less brake.

In all seriousness, don't sweat it. If you are going slow enough to watch your oil pressure gauge I guarantee it's not an issue. Deep sump baffle and XP-9 are the appropriate safeguards for tracking this engine. About half of the 996 racers I know also use an accusump but there is no evidence that they have less issues than the baffle only. As long as you don't money shift, these engines are insanely durable.

kondata17

I'm fairly certain that I have the original motor since its still throttle cable and not electronic. I'm a bit puzzled about why this would happen to some and not others, seems odd. I actually have a stand alone VDO pressure and temp gauge installed and watched the vdo unit display. Factory pressure gauge on the cluster is worthless as it sits at 5 bar the whole time. VDO unit shows fluctuation more inline to what I was expecting. The VDO pressure sending unit is installed on the opposite bank where the boxster would have its dummy light.

kondata17

I'm certainly not going fast, but I have the gauge set up so its easy to glance at mid turn. All I have to do is notice 30psi-25psi and I know things are not OK. I was running DT40 on track, watched temps get to 220-230 but the pressure drop happens well before oil temps start to creep into 230 range. I'm talking second hot lap.

I want to believe you that these motors are strong, but at 25psi at 6000RPM, no motor is gonna last.

Kris Murphy

So for me, as I exit the turn (under full throttle), I look down and see that it is between 1-2 or 2-3, it will climb back up. Also seems to happen much more on right hand turns.

I have also noticed it under full throttle on a NASCAR banked turn at Pocono (so plenty of time to take a peak).

BTW, this is the second time that someone has said if you are going slow enough to look at it, that there is not an issue. That doesn't make a ton of sense to me. Checking it (after I blew my motor) is something that is now just habit when I am on the track. I do it at the exact same spots throughout each lap. Just like checking for flags.

It's funny, I've never heard, "Well, you saw that red flag and came to a controlled stop, so you must not have been going fast"

Slakker

The reason is when you are riding the edge it's almost impossible to focus on anything else. Once I enter a corner, the only thing I'm looking for is my heads up marker or track out point. I've checked my mirror a few times and had the rear end decide it was sick of following and wanted to lead. That being said, without a full cage and safety gear, it's probably not a good idea to spend too much time on the edge. So that would make it a little easier to check a gauge. But it's something I would never do myself or recommend to someone else.

kondata17

youre right, for the most part I only check the gauge through slower corners or intentionally go through the corner slower to be able to look. so if its happening at lower speeds (lower G's), I can only imagine how bad it is when I dont check.

Slakker, so youre saying switching to XP9 has solved the starvation issue for you? Were you dropping oil pressure prior to running gibbs oil?

Kris Murphy

Will need to agree to disagree here, since basically what you are saying is unless something is at your track out marker you will not see it. It is dangerous to be that focused on your track out marker. By the time you are pointed at track out, you should already be looking at your next turn, and for flags, or debris, or the car that just spun in front of you...

Nickshu

I yell at myself as I enter a turn "eyes up, eyes up, eyes up".

Nickshu

In the short time that I have had my car I have tracked it with Mobil 1, DT40, and XP9. I was using the stock oil baffle w/ Mobil 1 and the EBSR metal door X51 baffle with the DT40 and XP9.

My anecdotal and approximate observations (on my car - 2003 3.6L stock C2 engine):

Hot idle coming off track on a hot day - 1.3 Mobil 1, 1.5 DT40, 2.0 XP9
Oil pressure drop noticed during high G turns hot engine (well into session), hot day - 2.0 Mobil 1, 2.2 DT40, 2.5 XP9

Slakker

I'm looking for apex in the brake zone and as soon as I turn in I'm already looking for my heads up track out marker. A tree, billboard, light pole, 3rd Martin house in the line. If there is debris on the track then that's the flagman's responsibility. If there is a spun car then peripheral vision will pick that up. If you want to be a better driver, lower your seat or block your windshield to where you can't even see the track 30-40' in front of your (recommended to me by a pro instructor). Eyes up is everything when it comes to driver improvement.

Here is picture of me going through a low speed turn in a race. You can't tell in the picture but I was extremely and intentionally focused on a set of tires a 50 yards away and not on the car in front of me.

As for the XP9, no, it prevents oil sheer not starvation. I've seen the Aim Data where oil pressure drops in turns but it looked spotty at best to me. And I have never talked to a race shop or an experienced 996 racer that had any concern for oil pressure drop in turns on the track. I encourage you to contact yours and see if they feel differently.

Nickshu

I think this is the best answer. Lots of guys tracking 996's and 997's extensively using Mobil Water with no problems.

Just drive it, take good care of it, but just drive it. If you blow it up...hey it's 4.0 build time. Nobody said this hobby could be cheap.

spruden

Are you using the standard gauge to measure oil pressure drops in real time - while hustling the car mid corner on track? If so - you're at best getting a very loose bit of information that likely isn't all that helpful to you.

There are so many variables that come into play - is your throttle/traction/RPM/G-force load exactly the same each lap? I've put roughly 10K track miles on my mostly stock 3.6 M96 - not taking it easy either.

Your best bet it is to do what the Spec 996 guys/gals do. If you don't know anyone who actively races then follow the SP996 class guidelines.

I'm a fan of a deep sump/baffle upgrade + running proper oil designed for wet sump track use (like the Driven XP series and others). Do these and don't worry about it.

As you do this more and more, it's driver error, debris, a mis-shift, or a "racing incident" that you worry about...not your M96.

Kris Murphy

Already had the mis-shift which is why I have the new motor in the car. What is so perplexing is that it seems so random. I have talked to a ton of people tracking 996s, some have the issue, some don't. Some have had the issue and the fixes listed above take care of the issue. Some have done all of the fixes and it still happens.

As I mentioned, this did not happen with my last motor.

I also don't think it is a byproduct of me just going faster. While this is my second year in the 911, I have been doing DEs for 8 years with close to 150 days at the track. Granted the first couple weekends in the 911 were slower than my normal pace, but I was not driving at a novice pace.