what's the right (engine) oil level for the track

[Jittsl]

Originally Posted by ppbon

... including my own, I am convinced that the Boxster NEEDS an Accusump system, especially when using sticky tires.
It doesn't matter whether you have the oil pan extension or the Motorsport AOS or the X-51 Baffles in the sump or anything other than an Accusump or a dry sump system.
The oil will creep up the sides of the sump and the pump will suck air.
One or two, or three laps like this won't kill the engine, but you do 3 or 4 20 minute sessions and the damage you're doing to the engine is unquestionable.
Take a look at my latest video and watch the gauges in the middle.
The right gauge is the engine's oil pressure.
The left gauge is the Accusump's pressure.
The center gauge is oil temp.
At 4:33 into the video the engine oil pressure sender's wire broke and you'll see the right gauge at zero. The left gauge (Accusump) still shows it's working.


If it weren't for the Accusump at every high-speed turn the engine's oil pressure would drop to zero, even though the RPMs are at 6-7K.
With the Accusump you see that as soon as the engine's oil pressure drops below 35 psi, the Accusump opens it's release valve and kicks up the engine's pressure.

Lap@Sebring.mov - YouTube

Happy Boxstering,
Pedro

Pedro, I would suggest that there was something wrong with the engine's oil pressure gauge long before it failed. Is that what you normally see? I also have an oil pressure gauge that I can see in my video and I have never seen it dropping under brakes (let alone around right hand corners) the way yours does. It doesn't appear as if the car is pushing particularily hard and yet any movement away from dead flat and the pressure drops - and that's with an accusump!

If that was typical I doubt these motors would last five minutes. I would be interested to see your next video after you make repairs to the wiring and (might I suggest) you swap the inputs to the two gauges to see if the response is still the same. I am taking it as a given that the oil level was correct. Just for the record, where did you attach your oil pressure sender?

[Topless]

Originally Posted by Jittsl

Pedro, I would suggest that there was something wrong with the engine's oil pressure gauge long before it failed. Is that what you normally see? I also have an oil pressure gauge that I can see in my video and I have never seen it dropping under brakes (let alone around right hand corners) the way yours does. It doesn't appear as if the car is pushing particularily hard and yet any movement away from dead flat and the pressure drops - and that's with an accusump!

If that was typical I doubt these motors would last five minutes. I would be interested to see your next video after you make repairs to the wiring and (might I suggest) you swap the inputs to the two gauges to see if the response is still the same. I am taking it as a given that the oil level was correct. Just for the record, where did you attach your oil pressure sender?

+1 agreed. No way the oil pressure is varying like that on every corner. Faulty gauge.

[jaykay]

Interesting discussion thanks all!

Okay I will have to get a gauge put in ....it may be digital to save space not sure if I will be okay without the sweep of a needle
....so I can learn what the normal response might look like

I have dealt oil pressure in aircraft only; it is steady or you have serious problems....oh and old MGB...not sure I believed any gauge on that panel

[Brad Roberts]

oh and old MGB

They had oil pressure?



B

[Brad Roberts]

I didn't watch Pedro's video... but now that I see it is from Sebring, I'll pull up some data I have from last years PCA Club race and take a look at it!!



B

[san rensho]

Originally Posted by Brad Roberts

They had oil pressure?



B

Exactly. How can a car that has all its oil on the undersides of the car (from oil leaks) have oil pressure?

[Jittsl]

Originally Posted by san rensho

Exactly. How can a car that has all its oil on the undersides of the car (from oil leaks) have oil pressure?

Now that is funny.

[jaykay]

Originally Posted by san rensho

Exactly. How can a car that has all its oil on the undersides of the car (from oil leaks) have oil pressure?

its been a terrible day....but I am laughing out loud!

er em back to the survery:

Deep sump: (1,5 L extra) with windage tray; extended pick up; slightly over filled stock AOS (now has a film of oil all over the top section); very little smoke

-pilot sports, PS2s

-currently car is run on a high speed type circut and and a tight technical track

[ppbon]

Originally Posted by Jittsl

Pedro, I would suggest that there was something wrong with the engine's oil pressure gauge long before it failed. Is that what you normally see? I also have an oil pressure gauge that I can see in my video and I have never seen it dropping under brakes (let alone around right hand corners) the way yours does. It doesn't appear as if the car is pushing particularily hard and yet any movement away from dead flat and the pressure drops - and that's with an accusump!

If that was typical I doubt these motors would last five minutes. I would be interested to see your next video after you make repairs to the wiring and (might I suggest) you swap the inputs to the two gauges to see if the response is still the same. I am taking it as a given that the oil level was correct. Just for the record, where did you attach your oil pressure sender?

... the reason it stopped working was because I didn't give the wire enough slack and it was a solid core wire (not stranded), hence it broke.
I don't see any oil pressure drop under braking, just under lateral acceleration.
Most of the turns at Sebring reach or surpass 1G lateral (with racing tires).
My engine's oil sender is located on the left bank port just under the left intake plenum and fuel injector bar.
Why would left hand turns be different than right hand turns as far as oil pressure is concerned?
The Accusump doesn't change the way the engine oil pressure behaves. That depends on the baffles and sump itself and how the oil reacts to the lateral forces.
It only opens up once the engine's pressure drops bellow 35 psi (or whatever other setting you desire). Once the pressure drops to that threshold the valve on the Accusump opens and oil under pressure is injected back into the engine.
Happy Boxstering,
Pedro

[Jittsl]

OK..... I just watched it again and every time you brake (or even slow down) the oil pressure drops. What aren't you seeing?

Right or left is different for some reason or another and typically these cars starve for oil under extreme left hand turns - or right hand if the engine is in backwards such as a 996. No idea why, just quoting what I have heard and what I have observed. Just for the record this does require in excess of 1g for sustained periods. Doesn't look like you would be even approaching 1g in the video you displayed and none of them look particularily sustained.

Brad, you would know better than me - does the behavior of Pedro's oil pressure gauge look right to you?

In my car whilst on the track the pressure reads 80-100 lbs (varying by temperature only) all the time if I am anything above idle. In your film your car is constantly dropping if you do anything other than drive straight and flat. Only three possible explanations that I can think of - the car is starving for oil because it is too low, there is something wrong with the oiling system and it cannot deliver the required pressure the minute the revs drop (such as braking or turning) OR there is something wrong with the gauge. Since it is a noname gauge with a dubious wiring setup I would be inclined to believe the later.

Laurie

[ppbon]

.... my particular gauges are electrically operated.
The sensor sends a signal to the gauge which has a servo motor so it reacts to every change of pressure quickly and accurately.
Many analog gauges are. Very slow to react do it seems that the pressure is steady when it's actually not.
Again, there is nothing wrong with my gauges.
What you may see as a pressure drop under braking is just the normal pressure drop from decelerating the engine's RPMs.
On the track the oil temp is much higher than normal and therefore less viscous do it also allows for a quicker drop in pressure than you'd normally see.
The video may not look it but almost every turn generates close to 1G lateral.
Happy Boxstering
Pedro