[rackley]

Originally Posted by Robin Hood

No offence, but you didn't study engineering did you?

I have.

Edit: If a N20 rates at 275HP at the crankshaft, then a N55 could do 275:2(litres)=137.5 x 3(litres)= 412.5 HP.
That's a lot.


Cheers
Robin

Sigh. The internet call out. I did. University of Michigan. Sorry to disappoint.

The comparison is not valid as they are not the same engine and more importantly, likely do not share many components. They are almost certainly using different injectors to support the higher flow rate per cylinder due to the higher boost. Are the piston rods thicker in the N20 than the N55 to support the higher boost level? Does the N20 have piston oil squirters? The N55? How many mL of oil is moved by them per stroke of the engine to cool the piston bottom? What is the actual heat transfer of that volume of oil from the piston to the oil? What is the cooling capacity of the oil cooling system that in turn removes that heat from the system?

BTW, if we're using the HP/L logic, the 328i engine made 193 hp / 2.8L = 69 hp/L. The N55 makes 100 hp/L. This dramatic difference in hp/L MUST mean the N55 is less reliable. Likewise, all newer engines MUST be less reliable than older engines that made less HP/L. See? The logic doesn't hold up.

There are many factors which I'm sure the BMW engineers have data on and have run through MANY complex simulations that we do not possess and are not running through ANY simulations. This has turned into just another internet debate - a lot of opinion backed by very little data. I'm just acknowledging we have very little data from which to draw a conclusion.

[Evooooo]

I feel like the Tq comes on much quicker than the E9X single...

[Robin_NL]

Originally Posted by rackley

BTW, if we're using the HP/L logic, the 328i engine made 193 hp / 2.8L = 69 hp/L. The N55 makes 100 hp/L. This dramatic difference in hp/L MUST mean the N55 is less reliable. Likewise, all newer engines MUST be less reliable than older engines that made less HP/L. See? The logic doesn't hold up.

Exactly, YOUR logic doesn't hold up, my friend.
Just never ever compare a NA engine to a turbo engine.

The 3 litre turbo 6 puts out less HP/litre than its 2litre turbo 4 brother, that's what we already know and thats what we are talking about. The more hp/litre of the N20 is excellent, but its downside is that it's more stressed out than the relaxed N55. I gave some examples(458/z06Vette, both NA).

So anybody who says the N20 is easily tuneable to 295/300BHP; Fair enough, but keep in mind a N55 is ALSO tuneable to 100BHP MORE easily. So I don't understand that argument. The only argument is $$$$ and that's why I drive a 335i and not a 991 or 458

Anyway.

Cheers
Robin

Come to think of it, my dad bought a E46 328i coupe 5MT back in 1999. He still has it. ITs'the engine you were talking about , 2.8 NA I6 with 192 DIN HP. 310,000kms. And still running fine, which means YES, with 69HP/litre whatever it IS MORE RELIABLE than 'my N55' and 'your N20'. Which means the N55 is logically more reliable than the N20....

[vladberca]

@ Robin: do you think that a N55 engine with more hp developed for let's say 435i/ 440i will be less reliable than the actual engine that is in the 335i/135i?
Also this is the case for 650i Coupe/ Conv. vs 650 GC!
N20 is developed after N55 and just has better performances related to its displacement, so is the case for the new v8 from 6GC and so will be with the N55 for the next 4 coupe/ GC

[Robin_NL]

Originally Posted by vladberca

@ Robin: do you think that a N55 engine with more hp developed for let's say 435i/ 440i will be less reliable than the actual engine that is in the 335i/135i?
Also this is the case for 650i Coupe/ Conv. vs 650 GC!
N20 is developed after N55 and just has better performances related to its displacement, so is the case for the new v8 from 6GC and so will be with the N55 for the next 4 coupe/ GC

No, because the 335/440 HP out differences are marginable...

And how come the older N54 produced more HP than the newer N55 per litre and now the newer N20 makes also more HP/litre. LOL explain that to me please.

It has nothing to do with newer. It has to do with greener and BMW keeping their marketshare vs their opponents....More hp/litre can make an engine less reliable in the long run. Also a smaller engine with high hp/litre like the N20.

After all, the N20 is a very fine and well engineered engine for a 4 cylinder, but hey take a look at Mitsu EVOs from a decade ago. Those HP/litre means nothing....until turbos blew to smithereens etcetera, with 300HP/2litre....and I know Mitsubishi builds great engines(I worked a while with the dutch Mitsu distributor here in Holland almost 20 years ago)

[vladberca]

N54 had quite a lot of problems (especially in its early days).. They changed the tech and released the N55 earlier than someone has expected.
The performance production nombers were the same for N54/N55. After that some performance kits were available and also different way of nameing: iS for US, performance kit for Europe...
For japanese manufacturers the maintenace intervals are way shorter (Nissan GTR included).

[vladberca]

Also my guess for the "upgraded" N55 440i version is that will have 340 hp

[Robin_NL]

I agree vladberca.

I had one of the first N54s in a E90 6 Mt back in sept 2006. The MT versions , including mine, came instantly with an oilcooler, the AT versions didn't. After a year or so as I recall the AT versions came with an oilcooler.

I had ZERO problems with my N54. I warmed it up, drove it hard, cooled it down.

WE'll see about the 340/440. The N55 can do 360/70HP within a blink of an eye, IF BMW AG wants to, that is....

[gatoman39]

Originally Posted by vladberca

Also my guess for the "upgraded" N55 440i version is that will have 340 hp

What ever they call it. 4 series coupe or 440i, or what ever, it will likely be driven by the N55HP, which is the tuned version of the N55 that puts out:

N55HP:
315 hp at 5,800 to 6,000 rpm,
330 lb-ft, 1,300 and 4,500 rpm

[bmrm396]

its been confirmed that the new F80 M3 will be N55 based (though details differ after that point) ... that should tell u all you need to know about what BMW thinks about this engine and its reliability

/thread

[E90Fleet]

Originally Posted by gatoman39

What ever they call it. 4 series coupe or 440i, or what ever, it will likely be driven by the N55HP, which is the tuned version of the N55 that puts out:

N55HP:
315 hp at 5,800 to 6,000 rpm,
330 lb-ft, 1,300 and 4,500 rpm

F01 LCI 740i should have a even higher rated N55 around June

[E90Fleet]

Dont forget the small amount of info around on the P Series engines listed as "BMW Sport" engines instead of the N Series (BMW GMBH) and S Series (BMW M)


So lots of things to come

[grimlock]

Without knowledge of the way the N20 is actually built, or having real samples of failures from over-boost, its hard to say definitively the N20 is more stressed.

But can still assume that, given the same (ok, who knows what is actually different?) N20 sits in both the 320i and 328, one giving 17x hp and one 245hp.
I think its a better idea to tune the 320i up to 328 levels.
Would I boost the 328i to ~300hp? -Sure, if you like sitting by the side of the road.
A hp/L comparison is only cursory/general given lack of knowledge of the specifics of how the engine is built.
If I got the 328i I wouldn't feel safe boosting it.
If I got the 335i I wouldn't feel risky getting 350-360hp from it.

btw. you can boost to get any HP number you want, my friend keeps telling me how he gets 500hp from his audi 2.0T.. but he's also on his 4th engine. At least that's what he tells me.

[Robin_NL]

Originally Posted by bmrm396

its been confirmed that the new F80 M3 will be N55 based (though details differ after that point) ... that should tell u all you need to know about what BMW thinks about this engine and its reliability

/thread

The block/displacement is 'N55' and that's about it I guess???

*note to self: I should take more time to read in the F80 M3 section*

[Robin_NL]

Originally Posted by grimlock

Without knowledge of the way the N20 is actually built, or having real samples of failures from over-boost, its hard to say definitively the N20 is more stressed.

But can still assume that, given the same (ok, who knows what is actually different?) N20 sits in both the 320i and 328, one giving 17x hp and one 245hp.
I think its a better idea to tune the 320i up to 328 levels.
Would I boost the 328i to ~300hp? -Sure, if you like sitting by the side of the road.
A hp/L comparison is only cursory/general given lack of knowledge of the specifics of how the engine is built.
If I got the 328i I wouldn't feel safe boosting it.
If I got the 335i I wouldn't feel risky getting 350-360hp from it.

btw. you can boost to get any HP number you want, my friend keeps telling me how he gets 500hp from his audi 2.0T.. but he's also on his 4th engine. At least that's what he tells me.

[M340i Pride]

so the bottom line is N55 puts out same power as before. if N55 and N54 output is same why such slow C&D 0-60 numbers.... (5.3) I was disapointed to say the least. F30 328i pulled out 5.7 or so in a earlier test. difference is now not that big. so who is going to pay 8k more for a 335i...?

[Sy546]

Originally Posted by bmwpride335i

so the bottom line is N55 puts out same power as before. if N55 and N54 output is same why such slow C&D 0-60 numbers.... (5.3) I was disapointed to say the least. F30 328i pulled out 5.7 or so in a earlier test. difference is now not that big. so who is going to pay 8k more for a 335i...?

$4000 difference when you option them out similarly. $45/month if your leasing, which a majority of BMW Owners are doing.

[bmrm396]

Originally Posted by Robin Hood

The block/displacement is 'N55' and that's about it I guess???


*note to self: I should take more time to read in the F80 M3 section*

yes sir ... haha ya its a lotta fun over there, i live vicariously through those guys.

Originally Posted by E90Fleet

Dont forget the small amount of info around on the P Series engines listed as "BMW Sport" engines instead of the N Series (BMW GMBH) and S Series (BMW M)

So lots of things to come

E90Fleet - what are these P series engines you refer to. never heard those mentioned before. is that sort of the M Performance line?

[E90Fleet]

Originally Posted by bmrm396

E90Fleet - what are these P series engines you refer to. never heard those mentioned before. is that sort of the M Performance line?

No one knows yet

All we know is there is a "P Series" of engines and they are listed under "BMW Sport" on BMW documents.
No info on the engines yet

Kind of like we know there is a N26 engine for the F30 with different turbos, but no one know exactly what its for yet

[Zephyr15]

Originally Posted by Robin Hood

Exactly, YOUR logic doesn't hold up, my friend.
Just never ever compare a NA engine to a turbo engine.

The 3 litre turbo 6 puts out less HP/litre than its 2litre turbo 4 brother, that's what we already know and thats what we are talking about. The more hp/litre of the N20 is excellent, but its downside is that it's more stressed out than the relaxed N55. I gave some examples(458/z06Vette, both NA).

So anybody who says the N20 is easily tuneable to 295/300BHP; Fair enough, but keep in mind a N55 is ALSO tuneable to 100BHP MORE easily. So I don't understand that argument. The only argument is $$$$ and that's why I drive a 335i and not a 991 or 458

Anyway.

Cheers
Robin

Come to think of it, my dad bought a E46 328i coupe 5MT back in 1999. He still has it. ITs'the engine you were talking about , 2.8 NA I6 with 192 DIN HP. 310,000kms. And still running fine, which means YES, with 69HP/litre whatever it IS MORE RELIABLE than 'my N55' and 'your N20'. Which means the N55 is logically more reliable than the N20....

Does the term "non sequitur" mean anything to you? It should, because you didn't respond to a single point rackley made about the unknowns associated with the development and design of the N20.

The fact that your father's e46 is still on the road tells us absolutely nothing about the N55 or N20.

[iwannabimmer]

Originally Posted by S.hasan546

$4000 difference when you option them out similarly. $45/month if your leasing, which a majority of BMW Owners are doing.

The difference is closer to $3k - $3,355 actually. $60 difference in monthly payments if you are buying. Add another $10-15 per month difference in gas.

Originally Posted by E90Fleet

No one knows yet

All we know is there is a "P Series" of engines and they are listed under "BMW Sport" on BMW documents.
No info on the engines yet

Kind of like we know there is a N26 engine for the F30 with different turbos, but no one know exactly what its for yet

Interesting....a N26 engine for F30s.....would that be for LCI F30s?

[E90Fleet]

Originally Posted by iwannabimmer

Interesting....a N26 engine for F30s.....would that be for LCI F30s?

No, current F30
Guessing its maybe something like a SULEV version or a low quality fuel version
Will have to wait and see