Accusump experience

[ScotcH]

Just another data point from me:

My car currently has the S52 oil pan with the VAC baffle and I run 1qt over factory specification without any oil cooler. I'm on NT01s and not super sticky tires like slicks though, so take that for what it's worth.

My car hasn't had a problem yet running in 100*F weather here in California doing several 20 minute sessions throughout the day.

Do you have an oil pressure logger?

[golgo13]

Do you have an oil pressure logger?

I do not.

[olemiss540]

Tbh "not having a problem yet" is just between everything is fine and "oh snap I have to spend a lotta money on a damn rebuilt motor". Not really anything in between those two points...

[ScotcH]

I do not.

Then I suggest you do not know if you have a problem. Without accusump, and with baffled pan, we would routinely see 0 oil pressure dips in the logged data. With accusump, those dips stop at ~20 psi min.

[golgo13]

All valid points. When I was saying I haven't had a problem, I mean my motor hasn't turned into a paperweight in four years.

EDIT:

Then I suggest you do know if you have a problem. Without accusump, and with baffled pan, we would routinely see 0 oil pressure dips in the logged data. With accusump, those dips stop at ~20 psi min.

How are you logging pressure with an S52?

[BlackHawkRacing]

All valid points. When I was saying I haven't had a problem, I mean my motor hasn't turned into a paperweight in four years.

EDIT:

How are you logging pressure with an S52?

Unfortunately, all the options I've found are expensive (AIM etc.)

[golgo13]

Gotcha. Wish I had more to add to this thread.

[bimmerboy318]

I elected to go with Achilles oil pan baffle and Accusump. I plan to use the Rally Road oil cap with the Accumsump. Loop the in/out ports and tee in. I'm either going to mount the accumulator in from of the radiator and use an electric valve, or mount behind passenger seat.

I too went back and forth with the S54 setup but buying used vs new ultimately swayed me toward Accusump.

[ScotcH]

All valid points. When I was saying I haven't had a problem, I mean my motor hasn't turned into a paperweight in four years.

EDIT:



How are you logging pressure with an S52?

AEM sensor, Aim dash.

[aeronaut]

My baffled oil pan and 1/2-1qt overfill, wasn't enough.
It ain't cheap to fix the oil pressure problem, and it ain't cheap to instrument and log data.
It also ain't cheap to replace lifters and cams.

I have the S54 pump setup, and pressure drops to 24 psi at a few places on most tracks for a few seconds, and otherwise 40-60 psi.

Interesting that the accusump solution results look similar.

[ScotcH]

Interesting that the accusump solution results look similar.

Yeah, it's quite amazing ... the oil pressure graph has peaks with RPM and loads, but the lower valleys are always a flat line at ~20 psi. Very happy with that. Also by looking at the pressure readout when the accusump is opened (engine off), it shows pressure for around 3-4 seconds ... so this will certainly be enough for most low pressure spots on track, but it's not nearly enough protection if your oil pump dies, unless you're REALLY fast to react to the alarm (our entire dash flashes red at <20 psi ... but still would be tough to shut it down in 3 seconds).

[aeronaut]

Fun with data.

8 laps of oil pressure data from Summit Main. (Lap times anywhere from low 1:22s to 1:25s, lateral G's +/- 1.4).
2 areas where pressure goes under 30PSI, with lowest at 23psi.
Shortly after T5 (slow hard left) at entry into T6 (slow hard right).
And T9, which is a fast long right.
Odd.

OP-8laps.jpg

[olemiss540]

What is amazing to me is that they (accusumps) are not more popular in the BMW world given the propensity for oil starvation. LS engines cars have been running this setup for a long time on road courses but I felt like I had never read of a thread on here with one before installing mine.

I understand they are a "bandaid" fix but the relative cost to a true fix leads me to wonder why they used to be taboo around here.

[aeronaut]

Knowing what I know now, I agree. If not pulling the oil pan for some other reason, I'd recommend accusump in a heart beat.