[TrackEnthusiast]

Originally Posted by sir_co2

early n55 with 206xxx miles, as long the oil pressure is reading above 30+ psi when smooth, street driving and passing 50+ psi when going hard, that should take care of the oil starvation concerns. invest in a good gauge application or something to read those values to keep an eye on it. these engines are at their happiest when they are topped up with 100%+ oil level.

Tottally agree with the 100%+ oil level. Every change I add 7.5 liters instead of the recommended 6.5. Recently, at the track, I've noticed that the pressure drops when trailbraking left were getting more pronounced. Since it was the 4th event since the last change, I assumed that the oil level had dropped because of oil consumption. Added .5 liters and everything back to normal.

[TrackEnthusiast]

Originally Posted by TrackEnthusiast

Tottally agree with the 100%+ oil level. Every change I add 7.5 liters instead of the recommended 6.5. Recently, at the track, I've noticed that the pressure drops when trailbraking left were getting more pronounced. Since it was the 4th event since the last change, I assumed that the oil level had dropped because of oil consumption. Added .5 liters and everything back to normal.

Eventually, when I need to pull the oil pan, I'll fucking weld an oil dipstick tube to the side of the oil pan. Idrive allways shows full... I am pretty sure many N55s had died because of low oil level thats never picked up by this stupid oil level sensor.

[AmuroRay]

Originally Posted by TrackEnthusiast

Tottally agree with the 100%+ oil level. Every change I add 7.5 liters instead of the recommended 6.5. Recently, at the track, I've noticed that the pressure drops when trailbraking left were getting more pronounced. Since it was the 4th event since the last change, I assumed that the oil level had dropped because of oil consumption. Added .5 liters and everything back to normal.

There is no oil pressure drop when you overfill? Do you have a log?

[Polo08816]

Originally Posted by TrackEnthusiast

Eventually, when I need to pull the oil pan, I'll fucking weld an oil dipstick tube to the side of the oil pan. Idrive allways shows full... I am pretty sure many N55s had died because of low oil level thats never picked up by this stupid oil level sensor.

Wondering if you can retrofit the M235iR oil pan (and entire sump system) to your N55. It does have an oil dipstick.

https://www.realoem.com/bmw/enUS/par...20Racing&mg=11

[AmuroRay]

Originally Posted by Polo08816

Wondering if you can retrofit the M235iR oil pan (and entire sump system) to your N55. It does have an oil dipstick.

https://www.realoem.com/bmw/enUS/par...20Racing&mg=11

I don't doubt you could, but it's 1K for the pan alone.

[Polo08816]

Originally Posted by AmuroRay

I don't doubt you could, but it's 1K for the pan alone.

Indeed it is. I bought the S55 retrofit kit but haven't installed it on my new N55 yet.

https://www.bimmerworld.com/S55-Oil-...-435i-N55.html

And you would have to buy the pan separately as mentioned in this kit.

Ultimately, it's the only OEM solution that is designed to sustain oil pressure. The Accusump systems only work for a limited time until you run out of oil in the reservior.

[TrackEnthusiast]

Originally Posted by AmuroRay

There is no oil pressure drop when you overfill? Do you have a log?

For clarification: I didn't say that there was no pressure drop, I said "Everything went back to normal". Then, let's try to get a consensus on whats the "normal" for a stock oil pan N55: If you go to the MMR pan baffle website, you'll see that they ran braking tests to showcase theyre product, comparing oil pressure drop with and without the baffle:



The takeway from the graph is that, in the worst case scenario, with the OE sump, you'll go as low as 1 bar and with the baffled sump as low as 2 bar. Note that these are gauge pressures (max pressure = 4.5 bar). So, based on MMR knowledge, as long as you don't go below 2 bar gauge pressure, you'd be fine. And that's what I ment with normal in my previous post.

Now look at the 2 footages below, specially at turns 5 and 7. Note: MHD pressures are absolute pressure, so subtract 1 bar from the readings to be in the same unit as the MMR testing.

In the first video, the oil level had drop, since it was the 4th event without changing oil. I can't tell by how much it had drop, since iDrive would still show full, so its likely that I was around the recommended 6.5 liters. Second video is the first event after an oil change, with sump filled to 7.5 liters.

Can you see that, with the 7.5 liters (2nd video), it behaved exactly like if the sump was baffled (minimum = 3 bar abs = 2 bar gauge)? Also, in the first video, the minimum was 2 bar abs = 1 bar gauge, which also matches the MMR test for the OE sump.

From all this my conclusions are:
- Pressure drop as low as 2 bar gauge pressure when trailbraking left is the "normal" for an OE sump N55.
- Filling to 7.5 liters and mantaining this oi level is as good as installing the MMR baffle, at least for my setup (street tires and OE+ suspension).

For the sake of everybodys leaning, it would be really nice if someone with the S55 sump could post a video/log of the oil pressures.

[Ilvez]

That's really good practical info here, man! It would be extremely interesting to see a log from S55 oil pressure around the similar track driving conditions.

EDIT: Small relief is that oil pressure drops only momentarily during hard braking and initiating left turn, then it picks up pretty quickly. No pressure fluctuations during long hard corners, left or right.

It would be interesting to know that those who have experienced N55 engine blowups in track then if they had oil filled to max?

[TrackEnthusiast]

So, as we learned in the previous posts that it is very importante to overfill and to keep an eye on the oil level, I started to look for ways of monitoring the level more precisely, since the iDrive info bar is garbage.

Browsing around in the ISTA+, which I allways take with me to the track, I've found a routine that will display the oil level reading in mm, even with the engine off. I believe my engine is still very close to the 7.5 l I added in the last change, and I also readed elsewhere that the maximum reading is 74 mm. When I ran the ISTA routine, I had 75 mm with engine off and 74-75 mm when reving the engine. Now I'll try to keep track of this readings and see if it correlates correctly with the oil pressure behavior I saw and described in the previous posts. Below the ISTA+ screen in which you can see the routine name to get this reading (this is a troubleshooting routine, so it will start asking you if you get propper Idrive oil level readings, to which you should answer yes. Then you continue and then the option to show the mm reading of the sensor will show up):

[Polo08816]

Originally Posted by TrackEnthusiast

For clarification: I didn't say that there was no pressure drop, I said "Everything went back to normal". Then, let's try to get a consensus on whats the "normal" for a stock oil pan N55: If you go to the MMR pan baffle website, you'll see that they ran braking tests to showcase theyre product, comparing oil pressure drop with and without the baffle:



The takeway from the graph is that, in the worst case scenario, with the OE sump, you'll go as low as 1 bar and with the baffled sump as low as 2 bar. Note that these are gauge pressures (max pressure = 4.5 bar). So, based on MMR knowledge, as long as you don't go below 2 bar gauge pressure, you'd be fine. And that's what I ment with normal in my previous post.

Now look at the 2 footages below, specially at turns 5 and 7. Note: MHD pressures are absolute pressure, so subtract 1 bar from the readings to be in the same unit as the MMR testing.

In the first video, the oil level had drop, since it was the 4th event without changing oil. I can't tell by how much it had drop, since iDrive would still show full, so its likely that I was around the recommended 6.5 liters. Second video is the first event after an oil change, with sump filled to 7.5 liters.

Can you see that, with the 7.5 liters (2nd video), it behaved exactly like if the sump was baffled (minimum = 3 bar abs = 2 bar gauge)? Also, in the first video, the minimum was 2 bar abs = 1 bar gauge, which also matches the MMR test for the OE sump.

From all this my conclusions are:
- Pressure drop as low as 2 bar gauge pressure when trailbraking left is the "normal" for an OE sump N55.
- Filling to 7.5 liters and mantaining this oi level is as good as installing the MMR baffle, at least for my setup (street tires and OE+ suspension).

For the sake of everybodys leaning, it would be really nice if someone with the S55 sump could post a video/log of the oil pressures.

Originally Posted by Ilvez

That's really good practical info here, man! It would be extremely interesting to see a log from S55 oil pressure around the similar track driving conditions.

EDIT: Small relief is that oil pressure drops only momentarily during hard braking and initiating left turn, then it picks up pretty quickly. No pressure fluctuations during long hard corners, left or right.

It would be interesting to know that those who have experienced N55 engine blowups in track then if they had oil filled to max?

https://www.fcpeuro.com/blog/bmws-s5...rmance-upgrade

BMW has always done a good job with its oil scavenging system while retaining the wet sump setup on BMW M cars, and the S55 is no different. While the S55 engine shares a lot of its basic engine block architecture with the non-M N55 engine, it uses an entirely different oiling system which does a phenomenal job of ensuring a healthy supply of oil to the bearings under all sorts of operating conditions. This system is good enough that it is utilized in the factory-built F22 M235iR/M240iR and the F82 M4 GT4 race cars. Aftermarket companies make baffles for the N55 pan, but they can’t match BMW’s OE engineering. Luckily, the shared architecture means your N55 can benefit from S55 parts.

BMW S55 Oil Scavenging System
Although the N55 and S55 have sensitive oiling systems, M Division's improvements are shockingly simple yet effective. For starters, the S55 engine utilizes a large main sump towards the rear of the engine. That part of the sump is where the oil drains, and the engine will pull oil from. To keep up with the M3 and M4 chassis requirements, BMW included an integrated baffle plate to keep as much oil as possible around the oil pick-up tube under extreme lateral forces. The N55 doesn’t have the integrated baffle and suffers because of that. Owners have found out the hard way that an aftermarket baffle is essential for their engines to survive repeated hard cornering on a race track.

The S55 also differs from the N55 as it has two oil pumps. The main oil pump, responsible for supplying oil to the engine, is driven off the crankshaft via chains but pulls oil from the central part of the sump. Working in tandem is the scavenge oil pump (driven by the main oil pump). It’s specifically tasked with ensuring there’s never a drop in oil pressure and pulls oil from four locations:

The front left of the oil pan
The front right of the oil pan
The front turbocharger oil return (cylinders 1-3)
The rear turbocharger oil return (cylinders 4-6)
The oil pulled from these four sources continually feeds into the main sump through the oil return flow pipe. The pipe forces the returning oil into a part of the baffle called the swirl pot, which drains the oil into the main sump even under the highest lateral or longitudinal forces. It’s a relatively simple system but incredibly effective when done right.

This system is so effective that BMW retained it for use on the F82 M4 GT4 and F22 M225iR/M240iR. Those race cars will typically use slick tires, allowing higher sustained lateral loads. Even in this extreme situation, oil starvation is not a problem. BMW claims that this system guarantees a consistent and constant oil supply up to a longitudinal acceleration of .61g down to -1.2g. Furthermore, this system ensures a constant oil supply of up to 1.2g of lateral acceleration (hard cornering, for example).



BMW N55 To S55 Oil Pump Retrofit
As mentioned earlier, this system is interchangeable with the N55 engine due to the similar engine block architecture. For those who track their rear-wheel drive, N55-powered BMW, you can add on this oiling system as a plug-and-play factory upgrade. Adding a baffle to N55 oil pans certainly helps, but the S55 system completely resolves any possibility of oil starvation without running a dry sump system.

You will need more than a handful of parts to retrofit the S55 oil scavenge system onto any N55 in an RWD BMW 135i, 335i, or 435i. With that said, the total cost of the retrofit is much less than the asking price for a used long block and doesn’t require a degree in rocket science to install. Everything required can be bought as Genuine BMW parts, though we recommend grabbing OE or OEM parts if you aren’t concerned about having a BMW logo on parts you won’t see.

[Ilvez]

Dude, that's one hell of a quoting. What are you saying? Buy S55 oil kit and be done with it? BTW, it does not fit F10 N55.

[TrackEnthusiast]

Originally Posted by Ilvez

Dude, that's one hell of a quoting. What are you saying? Buy S55 oil kit and be done with it? BTW, it does not fit F10 N55.

It dits on my engine, but doesn't fit on my pocket (at least new). I am still wheighing if it worth the risk of buying used parts, since those I can buy for a reasonable price.

[AmuroRay]

Originally Posted by TrackEnthusiast

It dits on my engine, but doesn't fit on my pocket (at least new). I am still wheighing if it worth the risk of buying used parts, since those I can buy for a reasonable price.

Just to be clear - you don't have an MMR baffle right?
And 7.5L - is that 7 1/2 bottles of oil? Do you drain out some after the event?

[TrackEnthusiast]

Originally Posted by AmuroRay

Just to be clear - you don't have an MMR baffle right?
And 7.5L - is that 7 1/2 bottles of oil? Do you drain out some after the event?

Answering your questions:

1- I do not have the MMR baffle, oil pan is 100% stock.
2-When I change the oil I do fill the engine with 7 and a half liters (aprox 8 qts) of oil, regardless of the size of the oil container (sometimes I get 1 liter bottles, sometimes 4 liter bottles and sometimes 5 liter bottles, depends on where the best price per liter is).
3- I do not drain any oil until its time for a new oil change.

[AmuroRay]

Originally Posted by TrackEnthusiast

Answering your questions:

1- I do not have the MMR baffle, oil pan is 100% stock.
2-When I change the oil I do fill the engine with 7 and a half liters (aprox 8 qts) of oil, regardless of the size of the oil container (sometimes I get 1 liter bottles, sometimes 4 liter bottles and sometimes 5 liter bottles, depends on where the best price per liter is).
3- I do not drain any oil until its time for a new oil change.

Hmmm...

[Ilvez]

Basically 1 litre of oil overfill gives extra 1bar of oil pressure during braking into left turns?

No downsides?