[Two4me]

I've been doing some research on this and was curious on what would be required to get M50i performance out of the xDrive50i G05's.

The most commonly known differences with the M50i's are:

• higher pressure (5000psi) injectors*
• larger twin-scroll turbochargers
• a redesigned intake manifold*
• upstream cooling radiator*

Based on that list, I thought it would be possible to upgrade so I did more research. Short story: it sadly isn't, but figured I'd post everything.

I found a BMW technical article in one of the other forums: https://g30.bimmerpost.com/forums/at...7&d=1548603301

Based on this, the following are also different from N63B44M3 and N63B44T3:

1. Cylinder head cover - Cylinder bank 1 - additional sensor mounts and modification of ignition coil screw connections in the N63B44T3 engine, cylinder bank 2: taken over from S63B44T4 engine.
2. Crankcase - Electric arc wire sprayed cylinder walls in N36B44T3 engine.
3. Crankshaft with main bearing - N63B44T3 engine: new main bearing shell materials introduced/crankshaft rebalanced.
4. Connecting rod - Forged connecting rod of N63B44M3 engine taken over from S63TU2 engine, N63B44T3 engine: forged connecting rod taken over from S63TU4 engine.
5. Piston - Piston skirt coating due to changeover to electric arc wire sprayed cylinder walls in the N63B44T3 engine.
6. Vibration damper - N63B44M3 engine: carried over from N63TU2 engine. N63B44T3 engine: carried over from S63TU4 engine.
7. Ignition coils - Rod-type ignition coil from N63TU2 engine in N63B44M3 engine. (31 kV) Modular ignition coil introduced in the N63B44T3 engine. (42 kV)
8. Spark plugs - Carried over from N63TU2 engine in the N63B44M3 engine.
9. Exhaust turbocharger** - Exhaust turbocharger carried over from N63TU2 engine in the N63B44M3 engine, but with Overboost function. New exhaust turbocharger in the N63B44T3 engine with electrical blow-off valves. New generation of bearing seats from the modular engines.

That 2nd one is a deal breaker and also an interesting typo from the document. Really, it seems a lot more is changed than just "a bigger turbo" unfortunately.

* Oddly, injectors weren't mentioned, nor was the intake manifold, nor a different cooling system.
** This is the only thing from the other list, but I listed the turbocharger differences here since it was explained better.

Just wanted to share this for anyone else that was curious of for other discussion.

[Frenetic]

The plasma arc cylinder walls was the thing that caught my eye. I know it seems rather mundane, but that cylinder wall—and how it’s made—has a large impact on oil consumption, among other things.

Usually, an iron cylinder lining is placed within an aluminum block. But to save weight, there are various spray-coat methods. Alusil and Nikasil (Silicon) are common (older) spray coat methods that was and is used in a lot of cars and, in my opinion, has an oil consumption problem. It’s just not very durable and will eventually wear away increasing the bore tolerances and allowing more oil to escape. Audi engines, with notoriously high oil consumption issues, are all Alusil I believe.

Plasma arc welding is more durable under a wider array of operating conditions and is less prone to wearing off. Hence, it offers better long-term oil consumption resistance, at least for that mode of oil loss.

So, it’s interesting they moved to plasma, which is good in my opinion, but that means they must have used something else for the previous iteration. What was it?

[Two4me]

Looks like it's Alusil:

The crankcase in the N63TU3 engine is manufactured from AlSi17Cu4Mg low pressure die casting,
same as the N63TU2 engine. The cylinder walls of the N63B44M3 engine are made of Alusil. The
same electric arc wire sprayed cylinder walls that feature in the modular engines are used in the
N63B44T3 engine. Like its predecessor in the N63TU2 engine, the closed-deck crankcase in the
N63TU3 engine features a double main bearing screw connection with side wall connection.

Details on the previous N63TU2 are here: https://www.bimmerfest.com/attachmen...ne-pdf.539778/

[Frenetic]

I bet the N63B44M3 has oil consumption issues as well (or will as these engines age). Alusil + Audi = Quart of Oil a month lol, so it's not hard to imagine the same thing happening with BMW's engines.

Originally Posted by Two4me

Looks like it's Alusil:

The crankcase in the N63TU3 engine is manufactured from AlSi17Cu4Mg low pressure die casting,
same as the N63TU2 engine. The cylinder walls of the N63B44M3 engine are made of Alusil. The
same electric arc wire sprayed cylinder walls that feature in the modular engines are used in the
N63B44T3 engine. Like its predecessor in the N63TU2 engine, the closed-deck crankcase in the
N63TU3 engine features a double main bearing screw connection with side wall connection.

Details on the previous N63TU2 are here: https://www.bimmerfest.com/attachmen...ne-pdf.539778/

[Two4me]

That's unfortunate for me. I just picked up a G05 xDrive50i (had to save money VS the M50i). It's at 45,000 miles too! I'll have to do more research on maintenance for this beast.

I was hoping to do performance mods on it but that might exacerbate the issue. Maybe we'll just upgrade to an M50i in the future. The main thing I wanted was the DHP though, so I'm thrilled with this SAV.

[Frenetic]

Well, not all Audis with Alusil consume oil. There’s just a correlation. So, your engine could be just fine.

Just like Arc-welded or even iron-cylinder lined engines can and do consume oil.