Following this thread, I came across some more speculation on the engine powering the next generation M3, called the F3x M3. In the past, SCOTT has mentioned that the N55 TwinPower inline 6 would be used as the base engine. No firm news yet, but here's some information on what BMW M is working on to turn the N55 into a real M engine.
First of all, it's my understanding that BMW M is still considering several engines or rather engine layouts for the next M3, so I can't tell whether this particular engine will actually make it into production, only that this is one possible layout they're looking into:
This engine -- let's call it S55 -- underwent heavy modifications to meet the prospective output of 450 HP:
- The displacement will be increased from 3.0l to 3.5l. We've had a discussion on this possibility earlier here, and came to the conclusion it wasn't possible based on the N55's cylinder spacing. What we didn't know back then is that BMW wouldn't touch the N55's bore, but implement this increase solely by adding stroke. In other words, crank and heads will be different from the N55.
- Furthermore, the S55 will have a new turbo layout. There's no word yet on the exact layout other than it will be aspirated by the help of three turbos. BMW followed a similar approach with the N63 V8 engine on its way to become the S63 engine powering the X5/6 M and soon the M5/6 models. The N63's two individual turbo chargers (each taking care of one bank of the V) were replaced with two twinscroll turbo chargers, and thus the amount of individual scrolls has been doubled. As some have suggested already, this approach can't feasibly be replicated on an inline 6 engine (or any 6 cylinder). There is no easy way to split the exhaust pulses of 6 cylinders into 4 turbo scrolls. Instead, three turbo scrolls were found to be the right solution. Whether that means one additional turbo to the existing twinscroll turbo of the N55 or three individual (single scroll) turbos, or even one tri-scroll turbo remains to be seen. Personally, I'd expect three individual turbos because that would allow for rather small chargers with a low inertia.
As of now, it sounds like the next M3 will only be available with a seven speed DCT transmission. No 6MT! Also, as things look now, there will be an F30 M3 sedan complementing the F32 M3 coupe and the F33 M3 convertible again.
We brought you the news of the X3 M reaching its mature phase of development last week. Now we can add the first, yet most important, fact about this car: It will basically share the engine with the F3x M3. In other words, BMW would choose the same route as with the X5/6M and let an early version of the S55 engine debut in the X3 M.
Finally, here's a heads-up for everybody disdaining BMW M's decision to turn away from high-revving, naturally aspirated, engines: You better be quick to put in your order for an E9x M3. The rumor has it that the E9x M3 ends production in 2011, including the E92 and E93 M3.
Best regards,
south
Uiteraard FWIW, maar South heeft wel directe lijnen met Scott................
idd the end of high reving ///M engines....................zoals boven vermeld; het vergroten van de slag komt het toerental niet ten goede..............
450 paarden uit 3,5 l maakt 128 PK/L.............das toch erg bescheiden voor een turbo..........150 PK/L kan makkelijk.........dat maakt al 525 PK..............komt ook meer in de buurt van een (X)M5-6...het gat wordt dan wel onbenullig groot IMHO
Toekomst; een berg koppel, bescheiden toename PK aantallen, lagere max RPM`s...........het enige waar we nog voor moeten vrezen is weer 100kg aan massa er bij.............
