N54 vs N55

[Dubso]

Advantages- dissadvantages, Pros-Cons

Considering there are not as many tunes availible for the n55 due to it being newer, but looking in the near future...dinan, giac..etc...

just opinions

[Dubso]

Originally Posted by ianf2002

You are brave opening this debate!

Im a noob, not brave.

Searched the forums a bit, didnt find that much.

Just dont want this to turn into a PS3 vs Xbox 360 war!

input is all. We all love BMW's after all, or we'd be in the "insert car manufacturer" forum.

[bogart]

[rader1]

N54 cars are certainly going to be cheaper, where an N55 is obviously going to be newer. N54s are also equipped with a forged rotating assembly, where an N55 is not. More aftermarket parts are available to the N54, however this is becoming less an issue. But the N55 is still young, there's lots more development work to be done. Also, with the N55 you only need to buy 1 instead of 2 as far dci and dps are concerned lol. As far as longterm durability, id go with the N54 due to being forged. But I'M NOT AN EXPERT, I'm sure someone will be able to provide more indepth info

[Dubso]

Originally Posted by rader1

N54 cars are certainly going to be cheaper, where an N55 is obviously going to be newer. N54s are also equipped with a forged rotating assembly, where an N55 is not. More aftermarket parts are available to the N54, however this is becoming less an issue. But the N55 is still young, there's lots more development work to be done. Also, with the N55 you only need to buy 1 instead of 2 as far dci and dps are concerned lol. As far as longterm durability, id go with the N54 due to being forged. But I'M NOT AN EXPERT, I'm sure someone will be able to provide more indepth info

+
Development is a big factor.
I have heard rumors about N55 being next M3 engine. Now that M has switched to turbos. I wonder how this will affect tunability or upgrades concerning the N55.

[larryn]

Wow.. this has been asked a bazillion time before, and usually leads to an argument.. The ole "My kid is better than your kid" kinda thing. I would suggest the OP do some research and make the determination himself/herself.

[Focusedintntions]

1 forged part does not a better engine make. A forge crank is useless with terrible bearings or if it's out of balance. Really at the end of the day it comes down to what you prefer. Drive both engines and see which one you prefer. The n54 has a much better midrange punch while the n55 has a better low end and top end (just barely on the top).

If you're looking to modify immediately and get the most power w/o having to wait for parts go n54. If you are going to start slower and gradually do more then maybe the n55 is for you.

In reality both are great engines built by bmw and I don't think there will ever be a definitive "better" engine. Unless either motor has some major destructive flaw that nobody has encountered. Go drive and pick one, either way I can guarantee you won't be disappointed by your choice and you'll have a smile ear to ear every time you press the accelerator to the floor.

[Juicehead]

Originally Posted by bogart

=+1

[Kcyrusm]

N54 has more mod support like they said, but it seems you can get more power out of the twin turbos with the available mods, for no at least.

N55 has slightly better gas mileage. Now real high pressure fuel pump issues with the N55 either.

Both great

[Impervious]

If you're not going to get into the tuning scene I'd suggest N55. Otherwise the N54 seems to be the better choice.

[rader1]

Originally Posted by Focusedintntions

1 forged part does not a better engine make. A forge crank is useless with terrible bearings or if it's out of balance.

I have to disagree with you here, in a performance application i'll want forged everything. Its stronger and when something does go wrong its less likely to 'shatter' and cause further damage. It used to be that a forged piston would be smaller than a cast or hyperuetectic at cold startup, due to different expansion rates, and could cause piston slap when below operating temp and cause premature wear. But metalurgy has come leaps and bounds since then and its a non-issue now as far as I know. I'm not making a statement for either the N54 or N55 here, just saying forged is superior to cast. I highly doubt a factory bmw crank will be using terrible bearings or be so far out of balance to cause probs

[JHOOPS2]

Originally Posted by Kcyrusm

N54 has more mod support like they said, but it seems you can get more power out of the twin turbos with the available mods, for no at least.

N55 has slightly better gas mileage. No real high pressure fuel pump issues with the N55 either.

Both great

I think mileage is a non issue. I average 30-31mpg on long trips with my N54 and JB4 on map2.

[Focusedintntions]

Originally Posted by rader1

I have to disagree with you here, in a performance application i'll want forged everything. Its stronger and when something does go wrong its less likely to 'shatter' and cause further damage. It used to be that a forged piston would be smaller than a cast or hyperuetectic at cold startup, due to different expansion rates, and could cause piston slap when below operating temp and cause premature wear. But metalurgy has come leaps and bounds since then and its a non-issue now as far as I know. I'm not making a statement for either the N54 or N55 here, just saying forged is superior to cast. I highly doubt a factory bmw crank will be using terrible bearings or be so far out of balance to cause probs

Oh no..please don't get me wrong i know forged parts have more strength than cast equivalents. I was just trying to dissuade the common argument that people make about n54 being better just b/c it has the forged crank. Just trying to say that you can't judge a motor by that one part, but have to do it by the sum of its parts.

[Aries932]

Having driven both I can tell you that both engines are quite amazing. On top of that both are easily capable of 450hp on stock internals. If you are planning on going further past that you might want to get the N54 not only for the forged crank, but due to the development that is already there.

As for differences the N55 turbo is much more noticable when driving. The N54 in comparison feels much closer to a naturally aspirated engine.

The one big advantage I believe the N54 has is that we know the strength of the engine. People have been running pretty crazy tunes on these cars and there have been minimal engine and turbo failures. The N55 is still young and we really havent seen how well it holds up to tunes.

On the other hand if you actually look at the power curve of the N55 it has shown to hold more power throughout the power curve after tunes (from 1000-5500 rpms), where as the N54 will spike power from 5500-7000 RPM's. The other advantage of the N55 is the DCT if that is your thing. Being able to shift so fast that there is no throttle closure or loss of boost is pretty amazing.

Anyways I am sure I will think up some other things later. I hope this helps.

[rader1]

Originally Posted by Focusedintntions

Oh no..please don't get me wrong i know forged parts have more strength than cast equivalents. I was just trying to dissuade the common argument that people make about n54 being better just b/c it has the forged crank. Just trying to say that you can't judge a motor by that one part, but have to do it by the sum of its parts.

ok, gotcha. I totally agree you can't judge an engine based solely on one part. I just get a feeling of a little more security knowing there a forged bottom end in my car, however I know one leaking injector left to sit over night or going to 1st instead of 3rd will make quick work of any engine lol
On a side note I'm glad to see this discussion and would like a couple vendors/race teams chime in on their thoughts

[blacknbean]

N54 has won engine of the yr last 4yrs...NOT the newer n55

[Freon]

Ug, here we go again. They're very similar...

[Focusedintntions]

Originally Posted by blacknbean

N54 has won engine of the yr last 4yrs...NOT the newer n55

Um actually from the 2011 awards.....

"
A BMW engine was able to repeat last year’s victory in the capacity class 2.5 to 3 litres as well. The jury voted once again for the 3-litre, 225 kW/306 bhp straight six-cylinder engine with BMW TwinPower Turbo technology, which is also featured in the new BMW 5 Series, in the new BMW X3 as well as in a 235 kW/320 bhp version of the new BMW 6 Series Convertible and the new BMW 6 Series Coupé. Its unique technology package comprising a Twin Scroll turbocharger, direct injection technology High Precision Injection and VALVETRONIC valve control ensures a particularly favourable relation between driving pleasure and fuel consumption. In this area, it even surpasses its predecessor, which was not only able to win the class valuation in the “Engine of the Year Award” competition three times, but also claim overall victory spanning several categories in 2007 and 2008."

Found on these very forums too....

http://www.1addicts.com/forums/showthread.php?t=532642

[Ash83]

the answer is simple .. if you have a MY11 car then you will argue that N55 is superior to N54. and if you have a MY10/09/08 then N54 is the superior engine

[Aries932]

Originally Posted by blacknbean

N54 has won engine of the yr last 4yrs...NOT the newer n55

/sigh...did you even bother to read over this years awards?

[Vectors2final]

http://www.bimmerfest.com/news/50432...t-engines-list

[Turbolader]

Surprised nobody mentioned this either.

N54 = Conventional throttle body
N55 = Bladeless throttle control (More Efficient)

N54 = 4 catalytic converters stock (US cars atleast)
N55 = 1 catalytic converter stock (US Cars)

One could argue that BMW feels more confident with the N54 because of the 335is and 1M, but that's awful speculative and something I wouldn't consider.

They're both great engines, ultimately someone thinking about buying an e82 is probably going to be whether or not they want the DCT (and getting the N55 because of it)