[ScottSmith]

Very cool! So they drop the balancer shafts? How smooth is the engine / how high do they rev it?

My concern is the offset crank of the N20 would make removing the balancer shafts a bigger deal than on a regular 4 cylinder. I have no data to back that up though. The balancer shaft mechanism is the biggest obstacle to building a proper sump for that motor.

[Maynard]

Why no love for the Accusump solution? It's not a dry sump, but cheaper and more reliable than funky baffled pans.

[PeanuKeeyes]

Originally Posted by Maynard

Why no love for the Accusump solution? It's not a dry sump, but cheaper and more reliable than funky baffled pans.

How big of a commitment is an accusump for a daily driver? It seems like it would be a pretty big pain when the car only sees a few track days a year. But I don’t know enough about it. With a baffled pan, the idea is you’re just upgrading an existing component without having to worry about a new maintenance item.

[khcoaching]

Originally Posted by Maynard

Why no love for the Accusump solution? It's not a dry sump, but cheaper and more reliable than funky baffled pans.

I think in my case, it's the plumbing and installation know how. I'd totally be up for it if it was a complete kit. Maybe it's way easier than I am making it out to be, but it seems every one has their own take and each installation is different.

Ken

[ngl]

Originally Posted by Maynard

Why no love for the Accusump solution? It's not a dry sump, but cheaper and more reliable than funky baffled pans.

I'm not dismissing it, but the problem for me is finding a suitable space for it in the engine compartment, I don't want it in my cabin, the car is also daily driven and oil lines are the last thing I want to see. Also, a cabin installation is considered a fire hazard depending on the events you race at.

I don't know what the oil change procedure would be with an Accusump installed, but the biggest problem for me is the very high cost of importing it.

The price for the accusump + the alu pan with baffles is about the same as the cost of the dry sump kit I mentioned a few posts ago ( for me at least, with import taxes / transport / etc ), so currently weighing the pros and cons of each approach.

Also, accusump + baffles is a treatment not a cure to the problem, the dry sump kit would be a cure, but I don't know enough about it yet to commit to that either.


The good part is, that both the dry sump pump and the accusump can be transferred to a future car, so it is a big investment, but one that doesn't need to be repeated entirely should the car change.

Originally Posted by ScottSmith

Very cool! So they drop the balancer shafts? How smooth is the engine / how high do they rev it?

My concern is the offset crank of the N20 would make removing the balancer shafts a bigger deal than on a regular 4 cylinder. I have no data to back that up though. The balancer shaft mechanism is the biggest obstacle to building a proper sump for that motor.

I don't know, I will ask and report back. The pictures I posted are not mine, they are from an installation they did on a N20 race car.

[Maynard]

Accusump is surely inferior to a dedicated dry sump system, no doubt. But for those who don't want that much commitment it is an option worth checking out (one I'd considered myself given all the concerns about even the big brother N55 starving during hard braking or long turns). I believe there is at least one forum member running a system, IIRC they told me they plumb theirs in fairly simply with one line/fitting. I didn't ask where they put the reservoir, but it can't be harder than fitting an oil tank. It has literally been decades since I was around a car with one, but my recollection is that you close it off just before shutdown to keep a pressurized reservoir, then open up the outlet just prior to cranking for a prelube effect. Once running the system re-pressurizes the reservoir, so you aren't ever running above-normal volumes in the pan. Back then this was via ball valves, but today it would be simple to do it electronically; you'd just need to figure out where to plumb the line into the system. To me this always seemed like the perfect solution for a sporadic but potentially fatal dip in pressures (dry sump systems are cool, but they can be a total PITA too - just spent time in line behind a guy w/ a Maserati who was getting a $650 oil change, largely to cover the multi-gallon tank full of oil he needed to replace). These used to be widely available on the used market too, if that makes international import duties easier to live with. I can't imagine they would really be as expensive as a good dry sump system, but I am not on the market right now.

[ScottSmith]

Originally Posted by ngl

I don't know what the oil change procedure would be with an Accusump installed, but the biggest problem for me is the very high cost of importing it.

Usually you just dump the accusump, change the oil overfilling by a quart or so, restart the car, then add oil again to max.

The price for the accusump + the alu pan with baffles is about the same as the cost of the dry sump kit I mentioned a few posts ago ( for me at least, with import taxes / transport / etc ), so currently weighing the pros and cons of each approach.

If you have an accusump, you don't need the aluminum pan with baffles. Though I'm surprised - in the US at least, dry sump kits are often several thousand dollars. Pumps themselves are at least $1000, plus bracket to mount, pulleys to drive it, sump. Contrast that with a Moroso 3qt accumulator, which is $215. Obviously I'm ignoring lines and fittings.

[ngl]

Originally Posted by ScottSmith

Usually you just dump the accusump, change the oil overfilling by a quart or so, restart the car, then add oil again to max.

Thx for the info, will be good to know if I end up going with the accusump

Originally Posted by ScottSmith

If you have an accusump, you don't need the aluminum pan with baffles. Though I'm surprised - in the US at least, dry sump kits are often several thousand dollars.

For the kit I found I was quoted around 2500$ ( pump, sump, mounting brackets and crank pulley ). This is without taxes, shipping, etc. The accusump for me is around 1200$, obviously cheaper but for just 1000$ more wouldn't a dry sump be the better option ?

I still need to see how this fits with stock ECU, the cars they build use aftermarket, so still many questions need answers.

[ScottSmith]

Originally Posted by ngl

For the kit I found I was quoted around 2500$ ( pump, sump, mounting brackets and crank pulley ). This is without taxes, shipping, etc. The accusump for me is around 1200$, obviously cheaper but for just 1000$ more wouldn't a dry sump be the better option ?

I still need to see how this fits with stock ECU, the cars they build use aftermarket, so still many questions need answers.

Demon Tweeks has the Accusump for 370 euro including VAT. Buy it before UK leaves the EU ;-)

You could try unplugging the MAP control for the oil pump and drive around (#4 on https://www.realoem.com/bmw/enUS/sho...diagId=11_4760 ). If the ECU goes into limp mode, then the ECU won't like the dry sump either (since either way it won't have control over oil pressure).

[ngl]

Originally Posted by ScottSmith

Demon Tweeks has the Accusump for 370 euro including VAT. Buy it before UK leaves the EU ;-)

I found the best pricing in Germany, shipping is cheaper also since it's closer to me, so no need rushing to buy it before Brexit. Still have more to learn about it. Also, when referring to the price for the Accusump, I'm including the electric shutoff valve, mounting clamp, check valve and the N55 thermostat housing to delete the heat exchanger and convert to oil cooler ( not including oil cooler in that price ). I don't think it can be plumbed in otherwise on the N20, but I could be wrong.

I'm also considering getting the LED kit and wire it to an analog input on the data logger to log accusump interventions.

I am not yet sure how to power it on. Starting it before the engine stars ( ex. on Ignition ON ) is reported to cause a CEL and possibly limp mode because the system will read to high oil pressure.

There is always the option of turning it ON manually when racing, because there is no oil pressure loss on street driving ( legally speaking ), but I fear I will forget about turning it off. Could probably use a latching relay that turns the accusump off when ignition is off.

And my third option is to control it from the data logger and turn it on when it detects a race track is entered, turn it off when exiting to pit.

If you have suggestions here, please share.

Originally Posted by ScottSmith

You could try unplugging the MAP control for the oil pump and drive around (#4 on https://www.realoem.com/bmw/enUS/sho...diagId=11_4760 ). If the ECU goes into limp mode, then the ECU won't like the dry sump either (since either way it won't have control over oil pressure).

Thx for the suggestion, I will try it. I am thinking such a conversion should probably need a special flash tune that accounts for these massive changes.

[ScottSmith]

Originally Posted by ngl

I found the best pricing in Germany, shipping is cheaper also since it's closer to me, so no need rushing to buy it before Brexit. Still have more to learn about it. Also, when referring to the price for the Accusump, I'm including the electric shutoff valve, mounting clamp, check valve and the N55 thermostat housing to delete the heat exchanger and convert to oil cooler ( not including oil cooler in that price ). I don't think it can be plumbed in otherwise on the N20, but I could be wrong.

You may have similar issues with the dry sump - I was looking at the pan trying to figure out how oil is injected back into the engine and I didn't see anything obvious. Do they assume you use an N55/S55 housing and plumb directly into that?

The N55/S55/etc thermostat housing does make installation of the accusump easier. It's *possible* you can use the port that the Z4 driver used for oil pressure, but it may not have enough flow to provide enough safety.

I didn't bother with a check valve.

I am not yet sure how to power it on. Starting it before the engine stars ( ex. on Ignition ON ) is reported to cause a CEL and possibly limp mode because the system will read to high oil pressure.

There is always the option of turning it ON manually when racing, because there is no oil pressure loss on street driving ( legally speaking ), but I fear I will forget about turning it off. Could probably use a latching relay that turns the accusump off when ignition is off.

And my third option is to control it from the data logger and turn it on when it detects a race track is entered, turn it off when exiting to pit.

If you have suggestions here, please share.

You don't need to use the accusump as a preoiler, so if your ECU doesn't like you dumping oil before starting the car, then don't do that.

A common setup is to combine an electronic solenoid with a pressure switch. That way the solenoid only fires when oil pressure gets low enough. You can then power the whole thing only when the ignition is on, or maybe when RPM is only over 2500-3000.

[ngl]

Originally Posted by ScottSmith

You could try unplugging the MAP control for the oil pump and drive around (#4 on https://www.realoem.com/bmw/enUS/sho...diagId=11_4760 ). If the ECU goes into limp mode, then the ECU won't like the dry sump either (since either way it won't have control over oil pressure).

More info on how the MAP contol works. This is used for Efficient Dynamics and fuel consumption. Operating in MAP "mode" is normal operation ( normal daily street driving ).

While racing, the ECU disables the MAP "mode" and switches to what is called "emergency mode" to increase oil pressure limit.

MAP mode limits oil pressure to 4.5 bar.
Emergency mode limits oil pressure to 5.5 bar.

Emergency mode is triggered while racing because one or more of the following conditions are met:

• high engine oil temperature
• high water temperature
• high engine revs for extended time

Emergency mode essentially turns the MAP controlled oil pump into a Volumetric flow controlled oil pump when needed.

Limp mode is triggered if the pressure can't be maintained ( is either to low - emergency valve stuck open or to high - emergency valve stuck closed ).

[khcoaching]

Update -

A rod ventilated the block right by the motor mount.....pictures forthcoming.

[khcoaching]

Postmortem shots....new motor is going together and I'll post pics of the baffled pan.

Ken

[PeanuKeeyes]

Originally Posted by khcoaching

Postmortem shots....new motor is going together and I'll post pics of the baffled pan.

Ken

Any updates on this?

[khcoaching]

Updates -

New BMW long block installed with:

VRSF Intercooler
VRSF Downpipe
CSF (?) Radiator
Injen Intake
Epic Tuning
Custom Baffled Alum Oil Pan (pics coming)

It resulted in 250rwhp and 300lbs torque. (I wanted to keep the stock boost level and the turbo is stock, just rebuilt)

I have yet to have it on track yet, as it has a small drivability issue at high RPM (too rich) and is getting retuned and I should have it back next week and on track.

Ken

[khcoaching]

Another UPDATE -

Tune issue has been a struggle but looks like it is resolved - Basically, it would go full rich and stumble, blowing black smoke out the exhaust over 5k. I took it back to the installer and they went over the entire intake system for leaks and none were found. Solution - Stock tune. A bit of a bummer as there for sure was some hidden power in there, but also a blessing as for what I am using the car for, stock boost is perfect and the car runs absolutely fantastic.

I also added a square 245/35/18 setup to it and its first track outing is in week.

Ken

[PeanuKeeyes]

Look forward to hearing how it goes! Still curious about that pan baffle if you’ve got any more info on that as well.

[khcoaching]

Originally Posted by PeanuKeeyes

Look forward to hearing how it goes! Still curious about that pan baffle if you’ve got any more info on that as well.

Sigh.....still waiting on pics. Track evening coming up soon!

[khcoaching]

Update from running it on the track -

Drivetrain - No other changes from post engine work other than it has the stock tune in it with the rear O2 coded out. Runs good and pulls clean with none of the top end missing issues I had. While it would be nice to have more power, for what I am using the car for, it's great. I did 1x15 session with me driving and then 3x1 hour student sessions and it ran flawless.

Suspension - Since the camber plates and and alignment, I added a 18x8 square setup with 245/35/18 Michelin 4S.....

So.....I drove this directly after driving my 1LE and it initially felt slow and soft. (HA! Of course) I drove it a few laps with my wife and rushed the entries and of course, forgot to lower the tire pressure and remove crap from the trunk, so it was probably 200lbs more than the previous run. Still went quicker than the pre-engine failure in near 40 degree higher temps.

At this point, it is a very fun and capable car and with cleaner driving and proper tire pressure, easily capable of running under 2min at The Ridge, which is very respectable given the very stock nature of the car.

Red is PRE- engine and stock staggered setup
Blue is POST - engine and square setup

Ken

[ScottSmith]

Any oil pressure data with the new baffles?

[khcoaching]

Originally Posted by ScottSmith

Any oil pressure data with the new baffles?

I did run a few laps looking at it with Bimmerlink, but didn't data log it. It was absolutely fine. I'll data log it with the Solo DL next time out.

Ken