[Reznick]

Correct me if I'm wrong but up until the e9X generation, the HP gap between the two cars never was that big.If I remember correctly, when I bought my wifes 330 in 2001 there was about a 40 HP difference between it and the 325.I can remember sitting in the showroom while ordering the car that that wasn't much between the two.

[Mangler]

'P' engines are designated for BMW Motorsport. Not ///M, but the race teams (F1, DTM, BTCC....etc). I doubt there will be 'P' series engines in any road going cars.

T

[Mahzari]

Originally Posted by UdubBadger

isn't rwd drivetrain loss more like 10-12% and awd closer to 20%?

From what I've heard, it's impossible to get a 10% drivetrain loss. A manual, rear-wheel drive car can get as low as 12-15%. Automatics increase drivetrain loss slightly. And, lastly, AWD cars are around 18-20%.

The standard for most dynos I've seen is 15%, but it's important to remember that multiplying by 1.15 and dividing by 0.85 are not the same thing.

275whp x 1.15 = 316 crank hp
275whp / 0.85 = 323 crank hp

All of that being said, dynos should only really be used to quantify the change in horsepower for a specific car, on a specific dyno, on a specific day. For example, a stock vs tuned 335i. It's difficult to compare different cars through a dyno sheet (the variance that people got with the N20 328i dynos shows that).

[clarence]

Originally Posted by Robin Hood

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.....


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....

Of course the N20 is more "stressed" than the N55, that is bourne by the BMEP figures. We can see that IC engines gets more & more "stressed" as time goes by, but it's debatable as to whether we should use the term "stress" or "efficiency".
I remember abt 15yrs ago, our physics class did some calculations & found that most petrol IC engines in the day had an efficiency of abt 30-40% (most of the energy is converted to sound & heat rather than kinetic energy). Recently, Mazda proclaimed that there are still a lot to gain from developing petrol IC engines by increasing efficiency. Therefore the gain in BMEP may be due to increase in efficiency rather than "stress". As the N20 is newer than N5x series, it's likely that BMW have applied even more advanced design into the N20 & so the marginal "stress" maybe less than we thought.
If u talk abt tuning, there's no need to argue cos inherently one has displacement of approx. 1,000cc more than the other. Naturally the N20 can be tuned to levels of a stock N55, but one cannot defy laws of physics.
Whether old engines are more reliable than news ones, again not enough statistics yet. Remember, new engines are much more complicated than old ones, so potentially more to go wrong. Plus, it seems that things nowadays are built to cost, so sometimes the design is quite marginal. As for the M52, before the technical update the cylinder liners had problems with high sulphur fuel.

[clarence]

Originally Posted by Robin Hood

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)

The 4G is a fine engine, produced since the 80's. Ralliart UK sold cars up to 360ps with official backing. Other great Jap engines that are substantially over-engineered include (but not exclusive to) Toyota's JZ & Nissan's RB.

[KevinJ]

This is just informational but here it is:

[albertabahn]

M 135i Will use a 320HP N55. Or will it be N54 as in the 335is. BMW states 6 ^ cyclinder petrol with OVER 300 HP. When does production of he N54 end? Any one know?

[AlexM]

Originally Posted by Robin Hood

But the car itself will last more than 3 years, as you know.....

Anyway, no worries, we're just talking engineering stuff and I'm stating the N55 is a very relaxed engine to have.

Cheers
Robin

I know It will be difficult to let it go

[ATX78703]

Originally Posted by albertabahn

M 135i Will use a 320HP N55. Or will it be N54 as in the 335is. BMW states 6 ^ cyclinder petrol with OVER 300 HP. When does production of he N54 end? Any one know?

so is 320hp / 330 lb-ft all we're going to see out of a "tuned" n55? that seems to be showing up in the 640i, this ///M135i, and the performance pack on the lci x6.

that would be disappointing, because that is less than the N54 tunes with the 335is, z4is and the 1 series M. they all had that crazy overboost 379 lb-ft thing.

[Whostheboss]

Originally Posted by mookie45

I bet they will bump the hp up even more when the f32 comes out next year.

prob not

[DrivenByE30]

Originally Posted by KevinJ

This is just informational but here it is:

Good Work! It seems that the F30 N55 is the most tamed of all 6 cyl...

[Michael Schott]

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...?

It's one test and who knows what the conditions were like? It seems like an anomaly to me. More likely the 328 will do 5.6-5.7 and the 335 5.0 seconds like the e90 335 N55.

[Titanium Silver]

Classic BMW...

[verbs]

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

The N55 already makes those numbers as it is, BMW just underrates the motor in the 335i from the factory.

So my question then becomes, is BMW's listing of the 640i/740i cars making 315hp just a marketing ploy, and it's the same engine with no other changes? Is there a difference in the N55 engine between the 640i/740i and 335i?

Mercedes and other automakers have done this for years, underrating motors of the lesser models that use the same engine as the higher end models.

[Elk]

Some manufactures use slightly detuned cams in their "lesser" vehicles, while still underrating all of the vehicles that use the same engine as to their respective outputs.

[RPM90]

Old thread I know, but I just wanted to comment on the N55 in my 335i.

I had a 135i with N54 right before I picked up my 335i Msport.
The N54 typically dyno'd with a bit more HP than the N55.

Having driven my 335i now for about 1400 miles, I am simply amazed at how much power this engine produces.
It also feels like big torque comes at a bit less rpm.

The really amazing part is that my 335i feels stronger/more powerful than my 135i N54 did. I have no dyno to back that up, just driving experience.
There is a long country road near my home where I have marked off a 1/4 mile. Take off in the 335i feels stronger, and by the end of the 1/4 my trap speed is at least 5mph higher than what I could get with my 135i.
The 135i is also a bit lighter than my 335i by 337lbs. That's a substantial weight difference.
The 135i was a MT and my 335i is sport AT.
Even to match the acceleration of the 135i my 335i has to be putting out more power. To beat it, it has to put out more still.

I bring this up because I'm thinking BMW upped the power in the newest N55, and may be waiting to make an official announcement about it when the new coupes arrive.
Other than that my 135i must have been a weak example of an N54 and my N55 must be an exceptional example.
Just to cover/match the 337lbs difference there has to be about
30hp/30lb ft more power. The sport AT isn't going to account for the higher trap speed, trap speed is about power output.

Anyway, this is all anecdotal. I'd love to see some dyno's from new 2013
335i's, just to see if there is something going on.

[Gardus]

Hi guys, I wanted to share our result of the X3 N55 on our Maha Dyno, it's extremely precise.
We haven't got the chance to test the 335i F30 (working on the 328i right now) but the engine is the same:


OEM:
Claimed data:
Horsepower 306,2 @ 5800 rpm
Torque Nm 400 @ 1300 rpm

Actual data:
Horsepower 314,8 Hp @ 5945 rpm
Torque 409,6 Nm @ 2850 rpm

With a full exhaust system (downpipe, cat, centre silencer, quad exhaust)
Horsepower 335 Hp @ 6085 rpm
Torque Nm 432,5 @ 3395 rpm



For comparison an E92 335i twin turbo on the same dyno:

OEM
Claimed data:
Horsepower 306 Hp @ 5800 rpm
Torque 400 Nm @ 1300-5000 rpm

Actual data:
Horsepower 323,4 Hp @ 5580 rpm
Torque 422,8 Nm @ 3765 rpm.

With the full exhaust system (downpipes, sport cats, centre pipe, rear muffler)
Actual data:
Horsepower 347,9 Hp @ 5630 rpm
Torque 448 Nm @ 4850 rpm.


Looks like the old engine response to a full exhaust was better.

[Robin_NL]

Mille grazie. Very interesting info.

I can't wait to get the BMW PPK in november/december.

Cheers
Robin

[Sharp_Cai]

No 4 cylinders for me~~ the hauling sound of N20 is horrible, and it's extremely loud. I am driving a 128i and G37S coupe, both with 6 cylinders, and both cars run smooth during the acceleration, not only the 0-60mph but also 60-110mph.

[BMWCali]

What I want to see is the ActiveHybrid 3 dyno'd! It's got an additional 55HP motor that also outputs 155 ft-lbs of torque, in addition to the 335i engine.

[BavarianFanatic]

Originally Posted by Sharp_Cai

No 4 cylinders for me~~ the hauling sound of N20 is horrible, and it's extremely loud. I am driving a 128i and G37S coupe, both with 6 cylinders, and both cars run smooth during the acceleration, not only the 0-60mph but also 60-110mph.

The thread is about the N55... ???