N54 vs N55

[oman135]

Both are good engines . Stock n55 feels better . ! I have seen a n55 with 380 whp !

[eleven11]

Just wanted to add that, yes, this is probably the best actual constructive thread on the topic (it went better than expected). Thanks for the great info.

[matt]

Drove a stock N54 for 3 years, now Im driving a stock N55.
Only diffrence I feel is sound (alot deeper) and it feels a tat more powerful.

No matter which engine you get, they are both awesome!

[Shawnski]

Vs my '11 n55. Truly apple vs orange as my '08 had the auto and my '11 has a manual. Seat of the pants and numbers don't lie though, it's a half second slower to 60 mph. The n55 is also considerably slower to 140.

I think that the N54 is underrated and the N55 is cheaper to manufacture. Any wonder why the N54 is used in the M One?

[cooler2442]

Originally Posted by Shawnski

Vs my '11 n55. Truly apple vs orange as my '08 had the auto and my '11 has a manual. Seat of the pants and numbers don't lie though, it's a half second slower to 60 mph. The n55 is also considerably slower to 140.

I think that the N54 is underrated and the N55 is cheaper to manufacture. Any wonder why the N54 is used in the M One?

You should have gotten the N55 DCT, it is faster stock than the N54 manual/auto and N55 Manual. DCT is only .1 seconds slower 0-60 than the 1M.

[CaptSlow]

The answer is simple. Run an N54 and an N55 at the 24h of Le Mans. He who finishes is the winner. If both finish, both win. Cheers!

[Turbolader]

Originally Posted by matt

Drove a stock N54 for 3 years, now Im driving a stock N55.
Only diffrence I feel is sound (alot deeper) and it feels a tat more powerful.

No matter which engine you get, they are both awesome!

I think the sound is mainly because of the cat-free midpipes that come with the N55, however it is a different turbo, so it could be that too.

[Aries932]

Originally Posted by Shawnski

Vs my '11 n55. Truly apple vs orange as my '08 had the auto and my '11 has a manual. Seat of the pants and numbers don't lie though, it's a half second slower to 60 mph. The n55 is also considerably slower to 140.

I think that the N54 is underrated and the N55 is cheaper to manufacture. Any wonder why the N54 is used in the M One?

Wow and just when I thought we were only getting constructive comments...you obviously think that the M engineers only take 6 months to do research and development on car.

Now I am not saying they would have picked the N55 over the N54...however I am saying they didnt have the choice of the N55 when M engineers went into development of the 1M 3 years ago. So to use that as an arguement is absolutely absurd and unncessesary.

[rader1]

Originally Posted by Aries932

Wow and just when I thought we were only getting constructive comments...you obviously think that the M engineers only take 6 months to do research and development on car.

Now I am not saying they would have picked the N55 over the N54...however I am saying they didnt have the choice of the N55 when M engineers went into development of the 1M 3 years ago. So to use that as an arguement is absolutely absurd and unncessesary.

Not trying to argue here, but just to play devils advocate. Since the N55 came out 2 years before the 1M(and obviously it was in development for years before release,) going by your logic: BMW engineers would've been fully aware of the of the N55's devolopment and soon-to-be implementation into the 1 platform. So there would've been a moment when a decision had to made which engine to procede with.

[Aries932]

Originally Posted by rader1

Not trying to argue here, but just to play devils advocate. Since the N55 came out 2 years before the 1M(and obviously it was in development for years before release,) going by your logic: BMW engineers would've been fully aware of the of the N55's devolopment and soon-to-be implementation into the 1 platform. So there would've been a moment when a decision had to made which engine to procede with.

Alright so in a search to find the actual timeline of the 1M coupe I came up with this. At least we have some evidence of the actual time frame of the development of the 1M.

Sadly enough for all N55 owners...what the N54 owners have been claiming has come true. I hate to admit that I was wrong, however I was. The 1M coupe was apparently the only car to take less than a 3 year development.

Here is what I found from this interview.

http://www.bmwblog.com/2010/08/29/bm...dr-kay-segler/

BMWBLOG: How long is the design process to produce an M car?

Dr. Kay Segler: It depends. We don’t compromise therefore we come later than the base model as you see with the new M5, because we don’t want to compromise. On the 1 series M coupe we were very, very fast – I mean tremendously fast! We took some risks but we managed it because we are a very small team, there is no hierarchy. Basically the principle idea was in June/July of last year that we might do something like this and we will bring it out next spring. So great job by the team.

[Vectors2final]

But they surely wouldn't take a another risk on a fairly new powerplant... I think they went with the N54 not because of superiority, but because of how long it's been around.

[rader1]

I drive an N54, but I bought the car without knowing much of the mechanical specs. I bought it bc I loved the way it looked, drove and just "felt." Honestly, if there had been an N55 there instead, that's what id be driving now, and to be honest I wouldn't be disappointed. I can't find a single reason to pick one over the other, at this point it's all suppositions.

[Aries932]

Interesting information I found about the N54 to N55 switch. Most of the information we know...some we do not.

http://www.mwerks.com/artman2/publis...Cylinder.shtml

Let us just say now that there’s nothing wrong with BMW’s N54 engine, the current twin-turbo unit that is, as of the 2010 Detroit show, offered from the bottom (135i) to the top (740i) of the company’s product range. In fact, we could give you a pretty long list of reasons why it’s one of the best engines in the world, and others agree—more than three years after its debut, the N54 is still winning awards left and right. But now there’s an N55, and supposedly, it’s even sweeter.

To believe that claim, you’ll have to wash your brain of the preconceived notion that more is better, because in place of two smaller turbochargers working alongside one another, BMW’s new turbo six goes to work with one single, albeit twin-scroll, turbocharger pumping in air. One thing that does carry over from the outgoing twin-turbo engine, though, is BMW’s attention to detail and the engineering team’s fight against turbo lag. As such, this new engine uses a very clever exhaust manifold and turbocharger design that is essentially a concentrated twin-turbo design. Inside the manifold, the front three cylinders are completely divided from the rear three, so while from the outside it appears that gas from all six cylinders is routed through one exit to the turbocharger, there’s actually a wall inside splitting the air in half. That splitting of air is continued right into the twin-scroll turbocharger housing.

The idea of this system is to split the pulses of exhaust gas so that regardless of where the engine is in its firing order, there’s always good pressure and as such, reduced lag. Additionally, the design allows for a lower exhaust gas counter-pressure buildup at low engine speeds, again reducing lag. It’s like having two turbochargers but without the complexity and like having one, only without the drawbacks of having to use one large, lagging turbo in place of two smaller ones. The best of both worlds.

Most of the engine’s efficiency gains don’t come from the turbo rethink, however. They instead come from the fact that this is BMW’s first ever combination of direct injection, turbocharging, and its Valvetronic system. The latter, which was used on the 3-series before turbocharging came into the story, is a fully variable valve management system. It allows for infinite control and adjustment of stroke on the intake side, making throttle butterflies unnecessary (though the throttle plate is not deleted completely, as it serves as a backup system in the event of Valvetronic failure.) As such, throttle losses are minimized while engine response is sharpened, since the exact air mass entering the cylinders can be measured more precisely. The result is better engine efficiency.

Valvetronic hasn’t been used on BMW engines with direct-injection thus far because there simply wasn’t room in the head to fit all of the components of both systems. This new generation of the system is more compact, allowing it to return. Additionally, this new Valvetronic uses a new adjuster with an integrated sensor that allows even quicker adjustments than before. According to BMW, the inertia factor of the adjustment process is just one-tenth of the former system.

For as much that has changed dramatically in the transition from N54 to N55, some things have been just slightly tweaked. This includes the power figures, which go from an even 300 hp and 300 lb-ft of torque to a increased 306 hp but a decreased 295 lb-ft. What the changes have done, though, is stretch the torque plateau down in revs. Instead of peak torque coming at 1400-5000 rpm, it is now served up from a low 1200 rpm on up to the same 5000. Peak horsepower of the twin-turbo engine came at 5800 rpm, and it still does, but it doesn’t drop until 6400 rpm. Displacement goes unchanged completely at 2979 cubic centimeters, but the new single-turbo layout makes this new engine about nine pounds lighter.

This is one of those have-your-cake-and-eat-it-too moments, because while the engine promises to have more responsiveness and a meatier power curve, it’s approximately eight percent more fuel efficient than its twin-turbo brother. The EPA hasn’t gotten its hands on anything for comparative purposes yet, but if we apply an eight percent increase to the manual transmission-equipped 2010 335i sedan’s numbers, they jump from 17 mpg city and 26 highway to 18.3 mpg and 28.1 mpg. Nothing dramatic, but still a good improvement. BMW would rather compare the efficiency to its old 4.0-liter V8, which made similar power but was 29 percent less efficient. In the N55’s first application, the new 535i Gran Turismo, that improvement in coupled with BMW’s new eight-speed automatic, which the company says is good for another six percent improvement in fuel efficiency versus its current six-speed.

Valvetronic, an advanced new turbocharger, and direct-injection. BMW is throwing every bit of its latest technology at this newest and greatest in a long line of award-winning inline sixes. We haven’t experienced it first hand yet, but we’re ready to call this one already—the N55 is a world-class engine. You’ll get your first opportunity to buy one in the coming months when the 535i GT hits our market, but expect it to trickle through the rest of the lineup slowly, as mid-cycle refreshes, or as BMW calls them, Life Cycle Impulses, take place. It will likely make it to the X5 next, and perhaps the 2011 3-series coupe and convertible. Last on the list will probably be the Z4 and the 740i, which won’t be due for improvements for some time still. But within a few years, don’t be surprised if the twin-turbo N54 disappears completely in BMW’s quest for higher efficiency.

[bogart]

lol wow

[Shawnski]

Originally Posted by cooler2442

You should have gotten the N55 DCT, it is faster stock than the N54 manual/auto and N55 Manual. DCT is only .1 seconds slower 0-60 than the 1M.

Yes, you are right I have the wrong transmission...the problem with the manual/gearbox in my opinion is it takes away the torque advantage of a boosted motor. The in and out of the throttle creates lag, that a hydro/auto or twin clutch/gearbox mask with seamless momentum...effortless torque - perfect for the daily drive grand prix.

[M135]

Yeah but you just can't replace the enjoyment of rowing the gears

[Shawnski]

Originally Posted by M135

Yeah but you just can't replace the enjoyment of rowing the gears

True that when the mood strikes!

[rader1]

Ok, so it looks like the only advantage the N55 really has over the N54 is the valvetronic. So here's my question: does anyone know if its possible to do a cylinder head swap? I've no experience at all with BMW engines, but I've done a few GM LSx engines and allmost everything is interchangeable and bolts right up.

[1SerieStud]

Originally Posted by Shawnski

Yes, you are right I have the wrong transmission...the problem with the manual/gearbox in my opinion is it takes away the torque advantage of a boosted motor. The in and out of the throttle creates lag, that a hydro/auto or twin clutch/gearbox mask with seamless momentum...effortless torque - perfect for the daily drive grand prix.

I think you chose poor wording for what you're trying to describe - there is a shift in momentum in between shifts, but if my car spinning 2nd, and chirping 3rd gear when I shift is not considered torque, then what is?!?

[Turbolader]

Originally Posted by rader1

Ok, so it looks like the only advantage the N55 really has over the N54 is the valvetronic. So here's my question: does anyone know if its possible to do a cylinder head swap? I've no experience at all with BMW engines, but I've done a few GM LSx engines and allmost everything is interchangeable and bolts right up.

The N55 uses a completely different engine management system (Which is why it's taking the community so long to release flashes for the N55). The N55 block is the same (I think) so the head may physically bolt up, but I don't think the oil passages will work, nor will the coolant passages.

If you really want to build power in the head, I would guess that you could get a nice port job along with slightly bigger intake valves (The N55 are a smidge larger, which would make me think there is enough meat to bore them out slightly -- although the DI injector is different, so the N54 injector may be bigger, and wouldn't leave you room to bore it out) Valvetronic is certainly more efficient (I would hope that all N54 owners would agree with me here) but there is a ton of things that need to be changed to make it work.

[Turbolader]

Originally Posted by 1SerieStud

I think you chose poor wording for what you're trying to describe - there is a shift in momentum in between shifts, but if my car spinning 2nd, and chirping 3rd gear when I shift is not considered torque, then what is?!?

I think what they are trying to infer is that the torque on the final drive is "interrupted" less in Auto's and dual-clutch trannies. The other thing, which (to my knowledge) only works with Auto trannies, is the fact that you can preload the drivetrain, and also build boost while sitting on the line. The Step is a ZF, and there are an awful lot of controls on it, so I'm not even sure if the ECU will allow you to brake-torque (e.g. not apply boost by limiting the wastegates or by not allowing the electronic throttle blade (in the case of the n54...or valvetronic profile in the case of the n55) to ramp up the engine speed.

Don't get me wrong, you can use a two-step to build boost at the line with a manual, but I don't know of one for the N54/N55 and it's an add-on thing, not a built-in thing.

I hope this doesn't turn into a which tranny is better deal...I drive an auto in my 1, but I have a manual for my other car. IMO, the superior tranny is the one you have, if you're happy with it

[M135]

Originally Posted by ianf2002

The fifth-generation M3 will be powered by a 3.0-litre twin-turbo inline six-cylinder engine that's believed to develop around 335kW of power from lower revs than today's model. Also expect a higher torque figure that's available almost off idle for greater flexibility and fuel efficiency...

What ever engine it will be, I'm sure N54 fans will go on how better the N54 is than the next gen M3's