Addressing N5x oiling and spun rod bearings (Accusump installed)

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Relegate

New Member
Oct 8, 2019
5
So regarding dual oil coolers.... I have a large setrab type oil cooler connected to the oem thermostat, and I still have the problem described. If the engine oil pump picks up air, I dont think it makes any difference how much oil is sitting in the oil cooler? The in/outlets are located on the top of my oil cooler, so the air would just push right though.

I also have a second oil cooler, which is driven by an electric pump connected to the front and rear of the oil sump, circulating the oil in the oil pan. I did try turning that pump on and off, and it doesn't make any difference in regards to the oil pressure issue. It just lowers the oil temps a bit. The oil is moved from the rear of the pan, ie out side the baffle, to the front of the pan. It makes sense that it doesn't help with oil pressure, because the issue happens when I trail brake, where the oil would already have moved towards the front of the baffle. In fact it might help to reverse the pump, but then I have the issue where it might run dry when accelerating. The rear of the pan is lower than the front.

And in general I would say, spend all the available cooling space on radiators instead of oil cooling. Three days ago a friend of mine hit +118C with this S55 on track, while his oil temps barely moved past 120C. My M135i friend would also hit power reduction due to coolant rather than oil temps here in the southern chinese humid heat.

If you update rods and bearings, you risk a bad installation which could lead to premature failure. Really I would say the easy answer is to go S55. It also has a pump to pull oil from the turbos under high G forces.

Regarding turbos for tracking you need something with headroom, so they have an easy job, and a turbo that uses the best exhaust wheel material that can handle the elevated egts. Look at the M235i racing. OEM turbos and less than stock power. That is my best advice. But you wont listen to that hahaha - I certainly didn't myself. Also look at the M235iR control arms for great inspiration.
Lot's of great points here! I have seen 3 S55's break at the track (1 the day my bearings went) and I know the crank hub fixes seem to work. I had actually considered just selling my 135i and grabbing and M2 Comp, but I'm not in a position to take on that payment increase. (the dealers are offering good deals on 2019's).

The engine rebuild would be done by a local BMW guy who builds E36/46 race cars for our AER series here in the states. His cars go very well, but the caveat is he is very busy and this would be side-work for him.... but I have time on my hands.

Is there a way to get the M2+ N55 dual pick-up (and pan) for our engines? I've been scouring the ebay, etc and haven't seen anything.

I've been running stock turbo, with JB4, then MHD and MHD was misfiring like crazy... I heard from some people the burble tune on track can cause issues? So, anyhow, I resigned to stock tune and kept improving lap times. But, I did run stickier tires (I normally run RE71 or NT01 and switched to the AR-1.) I chased down a supercharged e92 M3 and that's when the oil temps went crazy and I shut down on track (300F).

Plan for rebuild is a CSF 7046 Radiator as I have a DCT. I hear you about the aeration issues with any oil cooler.

I also run RaceLouvers.com hood extractors which have definitely helped with coolant temps as well as aero.
31841
 

Relegate

New Member
Oct 8, 2019
5
Here is a link to the M2 oil pick up- $87.62 USD. Would this work on our engines with the rest of the parts? (Pan, etc?) The more I read... the more I want to walk away. I lost the engine in my 911 and sold it as a roller and bought this 135i with that money. I had to replace the DME after a short (no thanks in part to the JB4 it seems) and I'm sort of over putting money into fixing things when I haven't even addressed the REAL upgrades (cooling, suspension, lsd). Maybe I take the $10k I would put into this car and just get something else?!
 
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Bnks334

Sergeant
Dec 1, 2016
397
New York
Here is a link to the M2 oil pick up- $87.62 USD. Would this work on our engines with the rest of the parts? (Pan, etc?) The more I read... the more I want to walk away. I lost the engine in my 911 and sold it as a roller and bought this 135i with that money. I had to replace the DME after a short (no thanks in part to the JB4 it seems) and I'm sort of over putting money into fixing things when I haven't even addressed the REAL upgrades (cooling, suspension, lsd). Maybe I take the $10k I would put into this car and just get something else?!
I provided a pretty lengthy reply over on 1addicts. As for ditching the chassis, it's really a financial decision for you to make lol. They aren't worth much as a roller and a used engine is fairly affordable in the grand scheme of things. You're in PA, right? I'll come scoop up your old engine lol. I wouldn't pay someone to rebuild to stock spec. Either go all out or just drop in something used. You can throw in some new bearings and re-seal it on the engine stand.

Do your own research before you become an example of the saying "grass is always greener." I know someone was raving on addicts about how they moved to an 8th gen civic and how great it is already with only a few mods... well, google "8th gen civic oil starvation," or, "BRZ oil starvation," if you want to see things of nightmares. All you see at HPDE is S55 and BMW's blowing up? Maybe that's because that's all you pay attention to lol. Not too many cars out there can run a race pace without needing to be heavily modified so pick your poison. This is why spec series are so popular. It keeps costs down vs being the fastest car ever like in some unlimited class time trial event...

M2 oil pan setup is not direct bolt-on. you need to fabricate a bracket to hold the power steering pump. Otherwise, you need the pan, pump, and pickup tube. It's not exactly an affordable solution either. I have seen some steals on Ebay, but, it's not a high volume car where there are a plethora of junkyard parts available. We could use an aftermarket oil pan. 1/2-1" deeper would fit fine and go a long way. Extended pickup tube to match. Shouldn't be too hard for someone to modify a stock pan for you. That's what N20's have done. Not sure to what success though. Combine that with a BETTER than vac's baffle.

The Accusump seems to work as advertised. I've provided logs a few times now to show the difference across autocross runs. I ran a 1:34.6 at thunderbolt earlier this season but didn't log oil pressures. I'm honestly not overly concerned about it. I was tracking this car for 3 year before it went. With the Accusump, I would bet I'll get at least another three years. This season has been great and I've put 8k miles on the rebuild so far. Maybe i'll drop the pan to see what the bearings look like over this winter.
 
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Asbjorn

Sergeant
Mar 10, 2018
473
Europe, based in China
Lot's of great points here! I have seen 3 S55's break at the track (1 the day my bearings went) and I know the crank hub fixes seem to work. I had actually considered just selling my 135i and grabbing and M2 Comp, but I'm not in a position to take on that payment increase. (the dealers are offering good deals on 2019's).

The engine rebuild would be done by a local BMW guy who builds E36/46 race cars for our AER series here in the states. His cars go very well, but the caveat is he is very busy and this would be side-work for him.... but I have time on my hands.

Is there a way to get the M2+ N55 dual pick-up (and pan) for our engines? I've been scouring the ebay, etc and haven't seen anything.

I've been running stock turbo, with JB4, then MHD and MHD was misfiring like crazy... I heard from some people the burble tune on track can cause issues? So, anyhow, I resigned to stock tune and kept improving lap times. But, I did run stickier tires (I normally run RE71 or NT01 and switched to the AR-1.) I chased down a supercharged e92 M3 and that's when the oil temps went crazy and I shut down on track (300F).

Plan for rebuild is a CSF 7046 Radiator as I have a DCT. I hear you about the aeration issues with any oil cooler.

I also run RaceLouvers.com hood extractors which have definitely helped with coolant temps as well as aero. View attachment 31841
Nice car!

Don't bother with the CSF radiator. It doesn't improve cooling. We are way down on cooler area compared to the S55, so start by increasing area instead of thickness.

As for the S55, here most of them overheat due to the dct oil temp actually. Have seen a few examples of that. Only seen one example where an S55 overheated due to water temps.

I provided a pretty lengthy reply over on 1addicts. As for ditching the chassis, it's really a financial decision for you to make lol. They aren't worth much as a roller and a used engine is fairly affordable in the grand scheme of things. You're in PA, right? I'll come scoop up your old engine lol. I wouldn't pay someone to rebuild to stock spec. Either go all out or just drop in something used. You can throw in some new bearings and re-seal it on the engine stand.

Do your own research before you become an example of the saying "grass is always greener." I know someone was raving on addicts about how they moved to an 8th gen civic and how great it is already with only a few mods... well, google "8th gen civic oil starvation," or, "BRZ oil starvation," if you want to see things of nightmares. All you see at HPDE is S55 and BMW's blowing up? Maybe that's because that's all you pay attention to lol. Not too many cars out there can run a race pace without needing to be heavily modified so pick your poison. This is why spec series are so popular. It keeps costs down vs being the fastest car ever like in some unlimited class time trial event...

M2 oil pan setup is not direct bolt-on. you need to fabricate a bracket to hold the power steering pump. Otherwise, you need the pan, pump, and pickup tube. It's not exactly an affordable solution either. I have seen some steals on Ebay, but, it's not a high volume car where there are a plethora of junkyard parts available. We could use an aftermarket oil pan. 1/2-1" deeper would fit fine and go a long way. Extended pickup tube to match. Shouldn't be too hard for someone to modify a stock pan for you. That's what N20's have done. Not sure to what success though. Combine that with a BETTER than vac's baffle.

The Accusump seems to work as advertised. I've provided logs a few times now to show the difference across autocross runs. I ran a 1:34.6 at thunderbolt earlier this season but didn't log oil pressures. I'm honestly not overly concerned about it. I was tracking this car for 3 year before it went. With the Accusump, I would bet I'll get at least another three years. This season has been great and I've put 8k miles on the rebuild so far. Maybe i'll drop the pan to see what the bearings look like over this winter.
Some great ideas here! Thanks for sharing.
 

drunkenup

Lurker
Dec 16, 2017
19
Fwiw I installed an oil pressure gauge prior to my last track day, tee'd into the oem pressure switch location, I have a VAC baffle as well, running Dunlop Z3s

Threshold braking and left turns do not bother oil pressure, it stays in the 70s, but the moment you combine the two and threshold brake, into left handers you can see pressures drop as low as 20 psi, maybe high teens momentarily.

For reference, NJMP thunderbolt's octopus sustained left turn shows no loss in pressure (involves no braking), but NJMP lightning's left hander at turn 7 (after a 120 mph braking zone, some braking into the turn) shows that drop. Again, I have the vac baffle, no baseline numbers.

Front pickup would be nice.
 
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Bnks334

Sergeant
Dec 1, 2016
397
New York
Fwiw I installed an oil pressure gauge prior to my last track day, tee'd into the oem pressure switch location, I have a VAC baffle as well, running Dunlop Z3s

Threshold braking and left turns do not bother oil pressure, it stays in the 70s, but the moment you combine the two and threshold brake, into left handers you can see pressures drop as low as 20 psi, maybe high teens momentarily.

For reference, NJMP thunderbolt's octopus sustained left turn shows no loss in pressure (involves no braking), but NJMP lightning's left hander at turn 7 (after a 120 mph braking zone, some braking into the turn) shows that drop. Again, I have the vac baffle, no baseline numbers.

Front pickup would be nice.
You are n54 and tapped into stock location? Can you post a log showing oil pressure from idle to 7k rpm? Curious what n54 pressure is as we've had a few different numbers posted.
 

drunkenup

Lurker
Dec 16, 2017
19
You are n54 and tapped into stock location? Can you post a log showing oil pressure from idle to 7k rpm? Curious what n54 pressure is as we've had a few different numbers posted.
I didn't hook up to a logger (actually have no logger to hook up to), but I can tell you roughly off the top of my head from looking at it so much on the street. I could possibly do a gopro video

Once oil temp is around ~215f (Castrol 0W-40 Euro Formula)
600rpm - 23-24 psi
1200rpm - 55 psi
1500rpm - 65 psi
peaks to a sustained 81 psi through the midrange but falls off to mid 70s around and past 6000rpms
 

Asbjorn

Sergeant
Mar 10, 2018
473
Europe, based in China
Fwiw I installed an oil pressure gauge prior to my last track day, tee'd into the oem pressure switch location, I have a VAC baffle as well, running Dunlop Z3s

Threshold braking and left turns do not bother oil pressure, it stays in the 70s, but the moment you combine the two and threshold brake, into left handers you can see pressures drop as low as 20 psi, maybe high teens momentarily.

For reference, NJMP thunderbolt's octopus sustained left turn shows no loss in pressure (involves no braking), but NJMP lightning's left hander at turn 7 (after a 120 mph braking zone, some braking into the turn) shows that drop. Again, I have the vac baffle, no baseline numbers.

Front pickup would be nice.
This is exactly the same problem I see. Trailbraking into left handers - bye bye oil pressure. Ever tried adding more oil?
 

Asbjorn

Sergeant
Mar 10, 2018
473
Europe, based in China
It just occurred to me... since the oil starvation mainly happens after braking and then turning left, maybe it would help if I reversed the flow of my oil pan oil cooler pump, essentially so that it would be moving the oil from the front to the rear of the oil pan instead?

mmexport1570255691236.jpg
 

rac

Corporal
Nov 14, 2016
127
Australia
gents - on topic you guys will know already most of this information but its an interesting listen and very encouraging for accusump use.
note at ~7 min it was meant to be said that dry sumps are cheaper than making a wet sump work for racing teams, and for the really time poor the accusump discussion from about ~11 min is the most relevant for most of us.

 
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Bnks334

Sergeant
Dec 1, 2016
397
New York
It just occurred to me... since the oil starvation mainly happens after braking and then turning left, maybe it would help if I reversed the flow of my oil pan oil cooler pump, essentially so that it would be moving the oil from the front to the rear of the oil pan instead?

View attachment 32339
isn't that how you have it running? The oil pickup is in the rear of the pan (left of pic). You want to be pumping fluid FROM the front (right of pic) to the rear. If your oil pump is pulling oil from the sump/rear and dumping it to the front of the pan then it's serving its purpose of oil cooling but not oil starvation.
 
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Bnks334

Sergeant
Dec 1, 2016
397
New York
gents - on topic you guys will know already most of this information but its an interesting listen and very encouraging for accusump use.
note at ~7 min it was meant to be said that dry sumps are cheaper than making a wet sump work for racing teams, and for the really time poor the accusump discussion from about ~11 min is the most relevant for most of us.

I watch the live session from time to time. Often information is too generic to be applied to any specific car but it's good for reinforcing what you think you know etc.
 

Asbjorn

Sergeant
Mar 10, 2018
473
Europe, based in China
isn't that how you have it running? The oil pickup is in the rear of the pan (left of pic). You want to be pumping fluid FROM the front (right of pic) to the rear. If your oil pump is pulling oil from the sump/rear and dumping it to the front of the pan then it's serving its purpose of oil cooling but not oil starvation.
Totally agree. I have it set up wrong given when the oil pressure drop happens. Let me try and flip the pump and report back.
 
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chris_flies

New Member
Nov 1, 2019
5
Woodbridge, VA, USA
In the OP, do you have your Accusump on the feed (to oil coolers, then rest of engine) or return (from oil coolers, direct to rest of engine) on the oil filter housing?

Does it matter? I would think that giving the Accusump the closest run to the engine possible would be advantageous, but I'm not sure which port is which...
 

F87Source

Lurker
Oct 14, 2019
12
I posted the gist of this in another thread but I am hoping that making a dedicated thread on this topic results in some CONSTRUCTIVE conversation regarding N5x oiling. Are there improvements that can be made other than just blaming oil? Or, are all the street racing bros right that Rotella is life? I think there is more to discuss here, myself...

I recently wiped my rod bearings on track at 115k miles

The above is a short rendering of lap #2 which was the only complete lap I got in for the second session of the day before the car rolled to a stop. Oil peaked 26xf and coolant peaked 220f on the straight. 3 turns later and it just died.

I decided to rebuild the engine myself. this gave me a first-hand look at what went wrong. Here is an album of all the pics I took during this process: https://drive.google.com/open?id=1CtV8pJYwjm-R2lBLrVuWmWSCevqbfJtD . I was a bit too busy with the build itself to worry about documenting key processes, but I can answer to the best of my ability any questions you may have. I was also a bit busy sorting out ECS Tuning's part # mistakes... Those guys really do just blindly throw crap in a box and ship it out.

From what I can tell, it looks like the oil pickup ran dry. The rod bearings literally melted themselves to the crank. The crank journals were not actually all that bad once the babbit material was peeled off. However, the crank took a ton of heat and so did the rods. I was lucky nothing let loose. Rod/journal #1 was the only one that looks like it got a bit of oil and fared a bit better than the rest.


Some notes from the tear-down: intake and exhaust cam ledges looked perfect still. The bottom end was burnt to a crisp. The cylinder walls, valves, pistons, and the main bearings looked OK with the exception of 115K miles of wear and tear. The cylinder head was pretty clean with no sludge (5-6k oil changes with Castrol Edge 0-40 EU). I have done multiple Blackstone analysis in the past and there was never any indication of an issue. In fact, they kept telling me to run my oil longer (7k+ miles). So, lets not go down that road of fuel dilution, thin oil, etc. Oh and yes, 7qts of oil drained out of the pan. In fact, it was about 1/2qt over-filled when this happened. I had just changed the oil the previous weekend and threw in the extra 1/2qt right before the event.

N54 and N55 failures seem to happen pretty frequently at the track. Sometimes there is so much heat generated that the engine throws a rod. In my opinion, the oil pan is pretty poor design for performance work. While the N55 did get a revised windage tray and oil pickup tube, over the outgoing N54, the pan itself is virtually the same for manual cars. The engine sits at an angle and the oil pan sits parallel to the ground. This results in a sump area that has a triangular shape/slant as one edge has to taper to meet the block. The horizontally cut and narrower pickup tube on the N55 seems to be an improvement over the N54 pickup tube for ensuring suction. However, neither pan has a baffle or any kind of provisions for ensuring the pickup stays wet. BMW points this out themselves on page 57 of the "S55 engine PDF." I can see how a situation like being 1/2-1qt low on oil and doing some high rpm pulls and then hard braking could easily run the pickup dry causing bearing wear. Or, if you're coming off a banked straight-away in 5th gear and toss your car into a few steady state turns...

To add to this, people seem to have really bought into the misnomer that N55 is "more reliable" than the N54 (yes the turbos and injectors might be but the bottom end has the same integrity) that they are buying N55's for track duty and thrashing them. It's not going to end well if you think a luxury commuter car can be "raced" on slicks without dropping some money into it. No, 60wt race oil isn't going to help you either. People love to say "LS swap it" but if you dig you'll find that just as many LS motors have had issues with oil starvation at the strip and track. I am not talking about the occasional beginner HPDE. If you want to get serious with the car, you'll need to get serious about oiling.

At autocross, I've logged ~10psi oil pressure under heavy braking. I never really thought much of it since "everybody does it so how can it hurt?" Well... 115K miles later, multiple HPDE days with rcomps, and 20+ autocross events and I am writing this post. I can't blame ll-01 oil, I can't blame dirty oil, and I can't blame "N55 intake camshaft oiling issues." I can only blame myself for ignoring what was a pretty transparent problem. It's even more funny to me now after tearing down the engine and seeing this issue first-hand and then seeing all the M235i owners at the track saying they bought their cars because they are more reliable than E-series N55. "Well BMW races the 235i." NOPE. Only the M235iR got the M2 oil pan...

Here is the M2 pan design (shares the same oiling system with the M3 and M4):

Not only is there a baffle to keep oil from sloshing away from the pickup, there is also a secondary pump which sucks oil from the front of the pan[and turbo drains] and dumps it to the rear (semi-dry system). Even this system is only rated for 1.2g of sustained g-force, per BMW. If only it weren't so expensive of an option... I'd definitely look into retrofitting this setup.

My current solution:
  • A slight oil pan baffle
I took some aluminum sheets and welded a ~1-1.5" wide "L-shaped" piece into the corner of the oil pan surrounding the pick-up tube. I didn't take pictures, unfortunately. I chose this L-shape as it mimics to a lesser extent what BMW did with the M2 oil pan. This is also similar to GM's "batwing" oil pan in the LS swap world.


Before anyone mentions it, I did not like the look of the VAC oil pan baffle. It looks like it would reduce the pick-up area to half of the sump and restrict the return of oil to the pickup in some situations. Turner has made baffles for previous generations, like the s52, which make more sense than this piece, imo.


A baffle alone is not going to cure this problem. It seems obvious that if you need an enclosure like VAC's to keep oil around the pickup that oil is not going to be returning to that trap fast enough either. Meaning, that ~1qt you managed to trap MIGHT last 1 full second before running dry itself... our cars can easily pump 3qts of oil out of the pan in a 2 second long sweeping turn or a 2 second long threshold braking situation like at the end of a drag run. On to the second solution:
  • A 3qt oil accumulator (Accusump)
While an oil pan baffle helps ensure oil doesn't slosh away from the pick-up tube, there are still going to be oiling issues in long sweeping turns. Hence, why BMW put a second pump in the front of the M2 pan. This is where I hope the Accsump will help.


The Accusump is plumbed into the oil return side of the thermostat housing and operated off an electronic valve. In the event that the pickup tube does run dry, the 55psi electronic valve on the Accusump will open at <55psi and allow the accumulated oil to be released. I went with the 55psi valve because the 35psi option just seems like too little too late given that our cars run at significantly higher pressure then that at all times. 35psi might make more sense for a typical car that sees 15psi at idle and 60psi under load. Oil pressure on our cars rises to around 80psi under load.

The electronic valve is always allowing oil to enter the accumulator so oil capacity and pressure inside the accumulator will naturally equalize to the PEAK operating pressure of the vehicle. I have seen the Accusumps accumulated oil pressure sitting at 110psi due to cold starts. This pressure is only allowed to RELEASE when the electronic valve is given the 12v signal from the pressure solenoid (pressure dropped below 55psi). Of course, the pressure bleeds off quickly when the Accusump starts to dumps but it takes several seconds for it to empty and drop below ~40psi. I will try to log the oil dumping to show how long it takes to empty when the car is off.

PSA: don't buy $2/ft nylon braided AN hose off EBAY lol You will be cleaning up oil for weeks when a defect in the line causes it to burst spraying oil EVERYWHERE. And, this lead to tons of other problems like killing my brand new tensioner, pulley, and belt. Don't be cheap and try to get away without replacing your belt after oil gets on it either. Mine shredded a week later and I ended up having to then re-do the brand new front crank seal and drop the oil pan. Nightmare.


I can quote use cases all day to support the effectiveness of the Accusump (lotus uses them), but, I am a skeptic and seeing is believing. Most of the negative things I have seen are user error (like killing the solenoid by allowing it fire 24/7 to dump oil at idle). Maybe I'll eventually buy an electronic pressure gauge so that I can log the Accusump activity. For now, I wired up a simple 12v light into my dash to illuminate when the Accusump activates.


Another benefit of the Accusump is that it can be used to prime the engine prior to starting. It can build 40psi oil pressure even before cranking on a cold start.

https://datazap.me/u/banks334/accusump-priming-engine-prior-start?log=0&data=4-13-16&solo=13&mark=62-32-86

The only drawback? I've hit a DME safety roadblock. The DME is seeing the higher then expected oil pressure prior to starting and throws a CEL. The oil pressure relief valve is then put into a fail-safe mode and the oil pump delivers 100% of its volume to engine (N55 has electronically controlled oil pressure). I don't think it's OK though to daily drive with 110psi oil pressure. This is something I ask the community to help figure out in order to make this feature of the Accusump usable.


Anyone else have thoughts or theories? Any actual "race" teams or engine builders have experience to share? Perhaps the tight bearing clearance results in high bearing temps? Babbit failure due to heat and/or compounding wear from intermittent oiling starvation issues? As seen in the pics above, my bearings literally melted to the crank. I know we've seen all sorts of theories out of the M motor spun bearing issues ranging from oil weight to rod bearing clearances. I've also seen also sorts of speculation about positive displacement oil pumps causing cavitation issues. I don't believe too much in this since the oil pressure sensor would see that type of loss of pressure... it would show in a log. I do think that there is some weight to the rod bearing clearances. I did not measure stock clearance since only rod #1 was measurable, but I did measure during assembly and I landed at right around ~.016" on all rods and mains. Some clearances were a hair wider or tighter. That is pretty tight for 40wt oil spec and close to a 2" diameter crank. KING specs .020"-.025" clearance for "performance" builds. I have also read that tighter than normal tolerances are perfectly fine on an aluminum block. It's hard to separate the facts from the fiction. Lot's of information is just regurgitated from decades old old-school knowledge.

Update:

Here is some autocross comparison data:
https://datazap.me/u/banks334/autocross-accusump
View attachment 25970

There are 3 logs there, the first log is with the Accusump, the second log is without the Accusump, and the third log is of oil pressure on decel in order to be able to compare actual oil pressure during the runs to what oil pressure is supposed to be.

You can see that oil pressure is dipping down to ~40psi during several turns and rpm is still above 3,000rpms which means oil pressure should be over 60psi. This could potentially indicate that the pick-up is grabbing some air. With the Accusump (60psi electronic valve), oil pressure is above 60psi across the run except in two places toward the end. Oil pressure dips in two places down to about 48psi. The short bursts of acceleration in an autocross probably limits how well the Accusump can re-fill. The results are still much better than the run without the Accusump.
Hey, what pressure do you have the switch do set at to trigger the accusump to start firing?
 

Bnks334

Sergeant
Dec 1, 2016
397
New York
In the OP, do you have your Accusump on the feed (to oil coolers, then rest of engine) or return (from oil coolers, direct to rest of engine) on the oil filter housing?

Does it matter? I would think that giving the Accusump the closest run to the engine possible would be advantageous, but I'm not sure which port is which...
It is plumbed into the return line (post oil cooler). When looking at the engine, the left ports are return. Right ports are feed. I dont think it matters too much though honestly. Pressure in the system is pressure. There is a drop across the cooler and lines etc but if you have your 60psi target pil pressure at the feed line I'm sure you'll be seeing 55psi+ at the oil pressure sensor location (main oil galley) too. I put the accusump on the return line so that it gets fed cooled oil and yeah it's also a later point in the system...
 
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chris_flies

New Member
Nov 1, 2019
5
Woodbridge, VA, USA
It is plumbed into the return line (post oil cooler). When looking at the engine, the left ports are return. Right ports are feed. I dont think it matters too much though honestly. Pressure in the system is pressure. There is a drop across the cooler and lines etc but if you have your 60psi target pil pressure at the feed line I'm sure you'll be seeing 55psi+ at the oil pressure sensor location (main oil galley) too. I put the accusump on the return line so that it gets fed cooled oil and yeah it's also a later point in the system...
Thanks! I guess that makes sense for cooling purposes. You do want a cooler to fill up, after all.

I’m going to spring for one and install it with my new front bumper and OEM 135i oil cooler. I’d like to get this motor to 250k...
 

Asbjorn

Sergeant
Mar 10, 2018
473
Europe, based in China
Finally got around to flip my pump so that it now moves the oil from the front of the oil pan to the rear of the oil pan.

mmexport1573507901303.jpg

Did the following tests to see if the pump would be able to pick up oil from the front of the pan.
Engine off - pump couldn't pick up oil
Engine on - pump couldn't pick up oil
added 0.8 liters of oil (idrive said oil level was around 70-80%)
Engine on - pump picked up a little bit of oil
Lifted the rear of the car, kept engine on - pump still only picked up a little bit of oil
Drove the car, applied hard braking while turning on the pump - now the pump picked up a good amount of oil

How did we know if oil was picked up you ask? Simply by touching the oil cooler to see if it got warm. I drove around with the bumper off:

IMG_20191112_163920.jpg

So based on these results, and to avoid having the pump run dry on track we decided to connect it to the brake lights in series with the hidden cabin switch. This means it will only ever run when the switch is on (which it will only be when I enter a track), and then only when I press the brake pedal.

IMG_20191112_171628.jpg IMG_20191112_204501.jpg

Hopefully this means I have oil pressure longer when trail-braking into left hand turns. Only testing will tell. Oil cooling will probably suffer a little bit, as the brakes are only on 10-20% of the time during a lap.
 
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