[Kbueno]

Originally Posted by scheherazade

Singles generally outperform duals.

It will just suffer more lag.

But with such a large engine behind it, the lag will be negligible.

Whatever HP/TQ the N55 is rated at, it is there by choice. It could be set 100 hp higher if they just felt like it.

Keep in mind that the N55 single is MUCH larger than the N54 duals, so it will be more efficient, and will have higher maximum power potential.

We don't have data on the N55 turbo. All we have is a picture, and in that picture it's helluva lot larger than the N54 singles.

My previous post that called the N55 single 'small', is simply in comparison to the turbos on an STI or EVO (where the large turbo makes up for a small engine). And for that matter, I'm stating my expectation.

-scheherazade

Originally Posted by Tortfeasor 335xi

So we have a bigger single turbo than our twin smaller turbos with lower peak torque. I think we should reserve judgment until we get to know more about this turbo's efficiency range. Lower peak torque RPM and lower peak torque numbers says that it likely moves less air than our twin turbos do in aggregate. Basically until someone really pushes the envelope with the new turbos and fueling system we wont know what this car can do with basic bolt ons and EM upgrades. At least with an upgraded Valvetronic (from Vanos) means that tuners will have more parameters they can tweak to help produce more power.

Interested to know which way this goes. The bigger question is what kind of gains can you get with a piggy from a larger single turbo vs. two smaller ones. I would think you'd get more from the 2 smaller ones with all else being equal, but without knowing the specs on the larger unit, its conjecture. Anyone have some insight into this.

[Upgrade+]

Wow, are our fmic that small? That thing looks like a long shoe box. That'll be one of the first to go and get replaced with after market.

Originally Posted by RiXst3r

Here are some better photos...

[NM_BMW]

Cool find!

[BMW_TT]

So they're slapping this engine in the 535 only?

[BMW_TT]

What sensor is that attached to the turbo housing?

[stressdoc]

Procede rev V.

[scalbert]

Originally Posted by BMW_TT

What sensor is that attached to the turbo housing?

I noticed that too and was trying to determine if it is truly on the housing. But it does look like it is. Maybe a speed sensor for the compressor.

[Alessandro]

Originally Posted by rcracer_tx

Why go backwards in performnce to a single turbo? the N54 has more torque, and would be just as good as an n55 for making power. I think BMW is pulling a marketing gimmick here with virtually identical engine with a small single because it is cheaper for them to produce...

i was reading the german announcment this week and its clearly stated the they want to keep the twin turbo only in the future for the M series. They also mentioned that the next M3 will be for sure a twin turbo I6. Either a 3 or 3.5 Liter which is not decided.

If you want the announcment i can put it in but its in German.

[flem]

Originally Posted by AJayE92

to make it less accessible

And the fact that down low is the only place to put the turbo since there is no way to mount the motor in the engine bay to allow the turbo to be put up top like with Supras

[flem]

Originally Posted by 335lvr

Interested to know which way this goes. The bigger question is what kind of gains can you get with a piggy from a larger single turbo vs. two smaller ones. I would think you'd get more from the 2 smaller ones with all else being equal, but without knowing the specs on the larger unit, its conjecture. Anyone have some insight into this.

Interested to know which way this goes. The bigger question is what kind of gains can you get with a piggy from a larger single turbo vs. two smaller ones. I would think you'd get more from the 2 smaller ones with all else being equal, but without knowing the specs on the larger unit, its conjecture. Anyone have some insight into this.

I would agree with scheherazade.

[retrodrive]

Originally Posted by Alessandro

i was reading the german announcment this week and its clearly stated the they want to keep the twin turbo only in the future for the M series. They also mentioned that the next M3 will be for sure a twin turbo I6. Either a 3 or 3.5 Liter which is not decided.

If you want the announcment i can put it in but its in German.

Oden's raven! I hope this info is real. I was afraid they would use V6TT.

[Driver72]

Originally Posted by Alessandro

i was reading the german announcment this week and its clearly stated the they want to keep the twin turbo only in the future for the M series. They also mentioned that the next M3 will be for sure a twin turbo I6. Either a 3 or 3.5 Liter which is not decided.

If you want the announcment i can put it in but its in German.

When did that announcement come out?
And where is it?

Reason I ask, is this is what I posted yesterday over on N54 at 1:30 pm after I saw the post about the N55 over there too.
Also, I predicted a 3.2-3.5 liter TT in the next M3 with 420+ hp may months ago. Seems I was pretty spot on.
Here's a copy and paste quote I made over their yesterday:

"Funny now how they are NOW saying the N54 gets peak torque at 2200 rpms, when they've been saying 1400 rpms since it's release.
I think we all know that at 1400 rpms we didn't have the torque we have at 2200 rpms.
Just like I'm sure there is no way with the new N55 engine will you get peak torque at 1200 rpms??

How the heck could that be possible really.
That's 600 rpms higher than idle.

How can any turbocharged engine, especially a single, boost up enough in 600 rpms to be at full torque already?

I'm guessing they are going to the single to save money as the priority.
Since it apparently makes the same power and probably same gas mileage, why else spend the money to switch to a single, if it wasn't going to SAVE them money in the long run.

I'll say it first and say it here...I'll bet the other reason for the single turbo is because the next generation M3 will be TWIN turbos and probably displace 3.2-3.5 liters from the 6 cylinder.

They don't want any "swapping" or "sharing" going on with the turbos and other parts, and having the N55 a single will make it VERY difficult, if not impossible to swap the M3's turbos (or any other supporting parts) onto the non M cars."

[marconi118]

Originally Posted by Alessandro

i was reading the german announcment this week and its clearly stated the they want to keep the twin turbo only in the future for the M series. They also mentioned that the next M3 will be for sure a twin turbo I6. Either a 3 or 3.5 Liter which is not decided.

If you want the announcment i can put it in but its in German.

Yes please post it, i could translate it

[Gumby_F80]

hopefully some1 will make a single snail turbo kit for the n54... (hint, hint)

[getInline]

Originally Posted by BMW_TT

What sensor is that attached to the turbo housing?

I bet they're finally building a boost limiter into the turbo itself or perhaps it relays some encrypted data to the ECU. That's what I'd be doing if I were them. I assumed they'd be doing something like that given the amount of time they've had to re-group.

[Alessandro]

Originally Posted by marconi118

Yes please post it, i could translate it

Here it is, i could translate to but i have to run a business.

Auch wenn wir schon kurz darüber berichtet haben, braucht der neue Motor im BMW 535i offenbar noch etwas mehr Aufmerksamkeit. Darum gibt es hier noch ein paar detailliertere Ausführungen als vor ein paar Tagen.

Es sorgt offenkundig für Verwunderung, dass der neue Reihensechszylinder mit Turboaufladung gegenüber seinem Vorgänger, dem N54 aus BMW 135i, 335i & Co., auf einen Turbolader verzichten muss.

Wie soll man mit einem einzigen Turbolader das hervorragende Ansprechverhalten des Biturbos realisieren, der ja grade davon profitierte, dass beide Lader relativ klein waren und daher schnell den nötigen Druck aufbauen konnten?



Zunächst einmal muss festgehalten werden, dass beim 335i - anders als beim 535d - zwei gleich große Turbolader zum Einsatz kamen, es handelte sich also nicht um eine Register-Turbo-Konfiguration, wie vielfach angenommen wird.

Der N54 hat also bezüglich seines Ansprechverhaltens ‘nur’ insofern von seinen zwei Turboladern profitiert, dass beide relativ klein waren und daher ihren Ladedruck schnell aufbauen konnten.

Das nun verbaute System ist bezüglich der Aufladung ein völlig anderes. Statt zwei Turboladern sehen wir nur noch einen, der nach einem bei BMW TwinPower genannten System arbeitet.

Dieses System finden wir auch schon in anderen Motoren der BMW Group, beispielsweise beim MINI Cooper S, wo es unter dem Namen TwinScroll firmiert - oder auch im neuen BMW X5 M sowie im BMW 760i F01.

Bei BMW X5 M und BMW 760i gibt es zwar zwei Lader, beide arbeiten aber nach dem TwinPower-Prinzip. Über den neuen V8-Biturbo aus X5 M & X6 M haben wir schon einmal ausführlich berichtet. Die dortigen Bilder eignen sich auch hervorragend zur Veranschaulichung des Prinzips.

Auch das folgende Bild stammt vom neuen V8-Biturbo und die Stelle, die uns im Zusammenhang mit dem N55 interessiert, habe ich einmal durch den roten Kreis hervorgehoben (Größere Auflösung bei Klick aufs Bild):



Wir sehen dort zwei tränenförmige Kammern im Metall, deren dünnes Ende auf ein kleines ‘Schaufelrad’ zeigt. Dieses Schaufelrad ist die Turbine des Turboladers und durch die beiden Kammern wird diese Turbine angetrieben.

Wie ihr wisst und der Name verspricht, wird ein Abgasturbolader von Abgasen angetrieben. Das besondere an diesem Konzept ist nun, dass aus jeder der beiden Kammern die Abgase unterschiedlicher Zylinder in den Turbolader gelangen.

Während bei einem herkömmlichen Single-Turbo, also einem Motor mit einem einzelnen Turbolader, alle Zylinder ihre Abgase an ein Schaufelrad schicken, gibt es hier eine Trennung der Abgase.

Die beiden Kammern sind es übrigens, die für das “Twin” im TwinPower oder TwinScroll verantwortlich sind. Der Begriff “Twin” ist allerdings nicht ganz richtig, denn es handelt sich nicht um Zwillinge. Eine der beiden Kammern ist eindeutig größer dimensioniert.

Während beim N54 jeweils drei Zylinder für einen Turbolader zuständig waren, sind nun beim N55 drei Zylinder für eine der beiden Kammern zum Antreiben desselben Turboladers zuständig.

Da beide Kammern aber unterschiedlich groß sind, wird zumindest die kleine sehr schnell mit Abgasen gefüllt und kann den Lader schon nach extrem kurzer Zeit antreiben.

Das “Turbo-Lag”, die “Gedenksekunde” der Turbolader, wird also ähnlich wie bei zwei kleinen Ladern deutlich verkleinert, obwohl wir nur einen einzigen Lader verbaut haben.

Zur Verkleinerung des Lags trägt auch der Fakt bei, dass die kleinere Kammer auf die großen inneren Flächen der Schaufelräder gerichtet ist, während die größere Kammer die Ränder der Schaufelräder antreibt und dadurch für noch höhere Drehzahlen der Turbine sorgt.

Die kleine Kammer sorgt also für das schnelle Ansprechverhalten, während die große Kammer zwar langsamer anspricht, dafür dann aber auch mehr Turbo-Drehzahl ermöglicht und damit mehr Luft in den Brennraum drückt, was im Endeffekt zu einem höheren Leistungs-Output führt.

Dadurch wird das Dilemma von SingleTurbo-Motoren effektiv umgangen. Normalerweise musste man sich entscheiden, entweder ein langsames Ansprechverhalten oder einen geringen Leistungszuwachs am oberen Ende des Drehzahlbandes in Kauf zu nehmen, weil ein einzelner Lader nicht beide Aufgaben gleichermaßen gut erfüllen konnte.

Neben dem TwinPower-Turbolader ist aber vor allem erwähnenswert und neu, dass beim N55 erstmals Turboaufladung mit Direkteinspritzung und Valvetronic kombiniert wurde.

Nur durch die Kombination dieser drei Faktoren konnte der außerordentlich geringe Verbrauch und das gegenüber dem N54 nochmals verbessere Ansprechverhalten realisiert werden.

Valvetronic ist die stufenlose Regulierung des Hubs der Einlassventile, was die Drosselklappe überflüssig macht. DieValvetronic steuert also die für die Verbrennung zugeführte Luftmasse im Motor selbst.

Der Verbrauch wird auch dadurch weiter optimiert, dass die Ölpumpe des Motors kennfeldgeregelt arbeitet, was ebenfalls Energie einspart. Außerdem ist der neue Motor, auch durch den eingesparten Turbolader, 4 Kilogramm leichter als der N54.

Im Gegensatz zu anderen Motoren von BMW ist dieser neue SingleTurbo-Sechszylinder nicht auf schwefelfreien Kraftstoff angewiesen und kann daher auf der ganzen Welt eingesetzt werden.

Die Aufladung mittels zweier Turbolader ist aber noch immer etwas besser geeignet, um maximale Leistung aus einem Motor herauszuholen. Es ist daher keineswegs ausgeschlossen, dass wir auch den 3-Liter-R6 von BMW demnächst wieder mit zwei Turboladern sehen.

Eine solche Biturbo-Konfiguration wird dann aber wohl exklusiv dem BMW M3 vorbehalten sein. Denn neben einem Leistungsplus sorgen zwei Turbolader auch für einen höheren Verbrauch als einer, was in einem M3 zu Gunsten von mehr Leistung akzeptabel ist, in der heutigen Zeit aber für Serienfahrzeuge unerwünscht ist.

[A418t81]

Originally Posted by scalbert

I noticed that too and was trying to determine if it is truly on the housing. But it does look like it is. Maybe a speed sensor for the compressor.

It's an electronic diverter valve. Very common these days. And yes, they can open it whenever they want now.

[BavarianBullet]

Originally Posted by Alessandro

i was reading the german announcment this week and its clearly stated the they want to keep the twin turbo only in the future for the M series. They also mentioned that the next M3 will be for sure a twin turbo I6. Either a 3 or 3.5 Liter which is not decided.

If you want the announcement i can put it in but its in German.

Please put it in.

Google translate FTW! http://translate.google.com/translate_t?hl=en#

Maybe those M guys finally complained enough that mildly modded 335s were giving them a hard time. Now we'll be getting one turbo and the Ms get two, just to make them feel the $25-$30k over a 335 was worth it.

What would be funny is if the single turbo and valvetronic proved to be a great combo that tuners could make even more power than from the N54.

[scalbert]

Originally Posted by A418t81

It's an electronic diverter valve. Very common these days. And yes, they can open it whenever they want now.

Hrmm, I was hoping for the speed sensor as that would be a nice data channel to have.

I have thought about the bypass valve but did not see any plumbing. But then again, little is shown in the image.

[A418t81]

Originally Posted by scalbert

Hrmm, I was hoping for the speed sensor as that would be a nice data channel to have.

I have thought about the bypass valve but did not see any plumbing. But then again, little is shown in the image.

There isn't any. There's a port in the compressor cover that the DV piston sits on top of. When it opens, the wasted boost is just vented medially through a "slit" in the intake portion of the turbo directly back in front of the compressor wheel.

[scalbert]

Originally Posted by A418t81

There isn't any. There's a port in the compressor cover that the DV piston sits on top of. When it opens, the wasted boost is just vented medially through a "slit" in the intake portion of the turbo directly back in front of the compressor wheel.

Great, so a valve seat to fail now and difficult to get too.

In others words, it is internal. I wouldn't image it would be too large. But any pressure bled at that point would be dramatic.

[NM_BMW]

Originally Posted by A418t81

There isn't any. There's a port in the compressor cover that the DV piston sits on top of. When it opens, the wasted boost is just vented medially through a "slit" in the intake portion of the turbo directly back in front of the compressor wheel.

Interesting... So possibly no more aftermarket DV's or BOVs. I know I wouldn't want to have to swap that thing out with aftermarket if it is going to be that hard to get too.