BMW F80 M3 / F82 M4 Under Mysterious Tarp? Engine Rumored to be Reworked N55

[bucket328]

Originally Posted by VTECaddict

I don't know what planet you live on, but all M engines have been modified "vanilla" engines, other than the S85 V10 and S65 V8. So a ground up "M" engine is actually the exception rather than the rule.

Im sorry but I do not agree with you one bit. You may, may be able to strip some of the engines right down to the core and find a minor trace of what once was a mainstream engine, but engines like the s54 and euro s50 b32 are not tweaked versions of regular bmw engines. Nowadays they are though.

[bucket328]

Originally Posted by SCOTT26

Actually, what you are looking at in terms of "reworked"
is a strengthened aluminium block with a heavily modified cylinder head , The Induction tech is completely all new as will be BMW's latest bi-vanos variable valve timing.
EfficientDynamics plays a huge part in not only lightweight chassis and body panel technology. Engine Stop-Start , on-demand ancillaries operation and Brake Energy regeneration will give the all-new M3 20-25% better efficiency than the current V8.

The First protypes of the BMW M4 Coupe will be seen later this summer.

Is it 100000000% confirmed they are going to call the coupe the M4??

[motortrend]

I hope the engine has more to offer that what can be done with bolt ons to the N55

[mkoesel]

Originally Posted by Uli_HH

None speaks about an chip tune ... but an re-inforced crank-shaft-house and an new (other) Turbosystem could easily be quoted by the BMW marketing as an heavily redesigned engine and an lightly modified valvetronic as an comlete new (heavily modified) cylinder head ...

And? Neither sounds "cheap" as you said in your first post. This won't be a cheap transformation by any means, unless you consider an S63 a cheap upgrade of an N63.

This very innovative charged-pulse system of the S63Tü only works on V engines, because it needs the cylinder outlets to be close together, so that the way for the energetic exhaust gases are relativ short before the reached the turbo scroll ... totaly impossible in any way to be adopted to an I6, where the distance between the first and the last cylinder is very long !!!

They aren't really that close:



The red and green paths in particular have long runners.

I don't believe for one second that it would be "totally impossible" to do something like this with an I6.

[mkoesel]

Originally Posted by SCOTT26

Some F32/F33 are now with full electricals meaning standard lights etc but
We should see the FEP F32 around August/September , The 3er GT is now in FEP so Bimmerpost photographers look out!

Thanks again for the info. I'm looking forward to seeing more of the F32 as are most of the Bimmerpost readers I'm sure.

[JJFESQ]

Do what you want with the rest of the line but M3 should be NA .

[///M3AN]

man, this kind of stuff just makes being in the "M club" more exciting! M3/M4 or not, BMW knows how to build anticipation....

[ScheerSpeed]

looks like they went to a 275 rear tire... definetly more power!

[SCOTT26]

Originally Posted by bucket328

Is it 100000000% confirmed they are going to call the coupe the M4??

Yes it is well known in the industry that the more sporting styles of the 3er - The Coupe , Cabrio and Gran Coupe will be designated as the BMW 4er.
The designation allows BMW to move the car further upmarket and charge a further premium.
The 4er family will also allow an eight model series under the F30 with Sedan , Touring and Gran Turismo seperated by the more sporting Coupe , Cabrio and Gran Coupe models.
The same with the BMW 2er - Coupe and Cabrio and potential four door would be split from the Sporthatch.

I don't doubt that the wheels match the F8X spy car photos. Keep in mind though, that the original concept E90 M3 was presented with CSL style wheels and not final production wheels. Perhaps they are showing this car with sportier wheels - or they haven't decided on final wheels for the F32 yet? Who knows, I'm just as curious as everyone else!

A complete image of the car would certainly help out!

You have to understand that these details are not final. I have seen prototypes which have used older style BMW wheels because they are still under design finalisation. A lot of these early proposals are not actually cars some are essentially clay models or fibre-glass models for evaluations - it is purely work in progress.
At this stage details are not essentially important.

[TOPHER325]

Originally Posted by SCOTT26

You have to understand that these details are not final. I have seen prototypes which have used older style BMW wheels because they are still under design finalisation. A lot of these early proposals are not actually cars some are essentially clay models or fibre-glass models for evaluations - it is purely work in progress.
At this stage details are not essentially important.

Precisely my point - thanks SCOTT26!

[swamp2]

Let's look at n55 being the base engine for the new M3/M3, specifically the bored vs. stroked issue for a larger displacement. I thought I may be able to conclude that the engine simply can not be bored alone to 3.2 liters, but this quick calculation does not quite show that, neither from pure geometric argument nor from a more engineering based argument. It almost shows it but not quite...

n55/n54
Bore: 84 mm
Stroke: 89.6 mm
Bore spacing: 91 mm
Displacement 2.979 l

Cylinder wall thickness between cylinders = 91 - 84 = 7 mm = .28". Just over 1/4 inch.

To get to 3.2 l (a rumored displacement) with bore change alone requires a bore of:

2*((3.2/2.979)*(84/2)^2)^(1/2)

Or 87.1 mm. Let's call it 87.

That would leave .15 inch of material between the cylinders. A shade more than 50% of what you can see in this picture (n54 block shown, these features are identical on the n55 block). Although this looks and feels too thin, engineering is not about look at feel. The stress in this portion of the engine will be roughly

σ = peak combustion pressure * (bore/2)/(thickness between bores)

(Note: This is the simplest thin walled cylinder approximation, which should be decent in this case.)

The peak combustion pressure (really rough estimate) is probably around 1000 psi (full load, high rpm). Anyone want to help me revise that estimate? This IS NOT BMEP, but peak dynamic combustion pressure.

Thus going from 3.0 to 3.2 liters by bore alone will increase the stress in this region by the same ratio as the wall thicknesses, nearly 200% in this case (x 1.86)!

The wall is certainly strong enough to handle a single combustion cycle. The limiting factor in design here is very likely "high cycle fatigue". This is just the repeated loading of the combustion cycle continuously weakening the material on the thin walled aluminum in this area. A practical limit for the allowable stress in typical aluminum alloys used for heads and engine blocks (say A356 alloy at an elevated temperature of 300 deg F) is in the 13000 psi range.

In the new 3.2 l hypothetical design the cylinder wall stress would be about 11000 psi. Very close the 13000 limit.

So in short, without sleeving, the n55 could likely enable a 3.2 l engine by bore increase alone. However, it appears to be producing a design very near fatigue limits. Thus, unlikely but not impossible.

My prediction for the engine is > 3.0 liter displacement and that will be gained by bore and stroke. I think that was also my prediction before this simple investigation...

As I've noted before even 400 hp from a 3 liter engine is already reaching the same hp/l as the Porsche Turbo. An additional reason I think the displacement must be going up.

[FogCityM3]

Keep the Tarp on! feels like the more details about the new M3 come out, the more that reality seems a lot less enjoyable than the fantasy.

[swamp2]

Originally Posted by m3alabama

400hp out of 3.0? Why is that so hard to imagine? As everyone knows a 500 dollar tune can get that now and even bmw's own 1m is putting down 340 whp which is right about 400 crank hp. That engine is already easily tuned to 450 crank hp.

With new valvetronic technology, lighter parts and a bumped redline to 7200 with 2 resdesigned twin-scroll's instead 1 twin,450 is not only possible but quite easy. Especially with slightly higher capacity turbo's that can move the peak power up the band slightly comapred to where it is now to take advantage of the higher redline possible with lighter parts and new valvetronic tech

You can also make the argument that you can get about 1000 hp/liter from an engine. The difference is a race engine vs. one that should with immense reliability go for 250,000+ miles.

By the way the 1M is not 340 wheel hp but 335 crank hp.

The comparison to the Porsche Turbo with 500 hp from 3.8, despite the totally different engine configurations, is fair one. Porsche has been doing reliable high performance twin turbo 6 cylinder engines for a long time. I don't see the first M3 with FI to radically exceed its power per displacement. 450 hp from 3.0 liters would exceed the Porsche by nearly 15%.

[Kayani_1]

I doubt it. The Nissan GT-R and Maclaren MP4-12c both race in GT3 class and in case of GT-R it also has raced in GT/GT1 as well as few of the other racing series across the world. Also, CTS-V races in SCCA etc.

In time the most racing series will adapt to the influx of force induction and hybrid cars. Infact most already have.

Originally Posted by bimmerjph

+1

The only nock I see on the upcoming engine is that I think the turbos will keep it out of a lot or racing series. Correct me if I am wrong though.

[aus]

Originally Posted by mhabs

Keep the Tarp on! feels like the more details about the new M3 come out, the more that reality seems a lot less enjoyable than the fantasy.

Sad, but true.

Originally Posted by m3alabama

Actually look at all the dyno's out there. Atleast 4 or 5 independant's floating around and all are above 330 whp. Clearly underrated per usual for bmw's FI engines. So I that puts the 1M right at 390 crank hp consistently and I am sure bmw designed it to "last"

Is that stock??? Those are INSANE numbers. That's just under what E9x M3's dyno stock!!! It doesn't overheat at the track either, like the N54 does.

Originally Posted by bucket328

Im sorry but I do not agree with you one bit. You may, may be able to strip some of the engines right down to the core and find a minor trace of what once was a mainstream engine, but engines like the s54 and euro s50 b32 are not tweaked versions of regular bmw engines. Nowadays they are though.

Agreed. For all those saying all the //M engines are based on M/N engines, what was the S52 based on?

.

[swamp2]

Originally Posted by SCOTT26

Yes it is well known in the industry that the more sporting styles of the 3er - The Coupe , Cabrio and Gran Coupe will be designated as the BMW 4er. The designation allows BMW to move the car further upmarket and charge a further premium.

I know the new M3 and M4 will perform. Nonetheless one can not deny there is just something wrong with a lightly massaged n54 with close to 500 hp in a 65-70k base M4 (guessing the M4 will have even more power than the M3 and will also exhibit engine "reuse" to maximize profit). I guess as long as the cars continue to dominate their classes I can't complain too much. Nonetheless small details like this make the cars undeniably less special and have me looking seriously outside the M brand for the first time in a long time.

[swamp2]

Originally Posted by m3alabama

Actually look at all the dyno's out there. Atleast 4 or 5 independant's floating around and all are above 330 whp. Clearly underrated per usual for bmw's FI engines. So I that puts the 1M right at 390 crank hp consistently and I am sure bmw designed it to "last"

I am not talking about a full on race engine but rather a lightly tuned engine which has been going on for 4 years now in the n54 community and engines with 150k miles are running strong. I am saying all they have to do is strengthen a few internals and EASILY could get 450 crank out of 3 litres and I mean easily. Then add new valvetronic with a higher redline and new turbo's and 3 litres is enough to easily push 500hp.

There is zero chance this engine will be bigger than 3.0l. Just not going to happen

Getting a bit OT but that's OK I guess...

The first 1M dyno I happened to pull open showed 331 hp (insideline). Either way I trust dyno's about as far as I can toss the crumpled up paper it is printed on. Loss is generally ARBITRARY in a dyno. The only dynos I really trust are from rri.se and they have not done the 1M. Anyway, performance numbers do indicate the 1M may be a bit under rated and I agree that this phenomena seems to exist across multiple FI BMW vehicles. The 335i is clearly underrated. However, the 1M just does not have 390 nor 400 crank hp. No way. 390 crank hp would give the car a superior power to weight ratio than the M3. Curiously enough it never outperforms it.

I doubt the internals of the 1M would need strengthened to reliably offer 450 or even 500 hp. It is all of the other stuff - oil cooling, air cooling, oil pump, water cooling/water pump, etc., etc. It almost certainly has a forged crank, rods and pistons already. There is so much more that goes into an OEMs plans around a vehicles power than most enthusiasts can even fathom.

I can see the argument that the displacement will be 3.0 liters. I'm by no means 100% sure it will be > 3.0. I just think it is most likely.

Also, I highly doubt we will see 500 hp from a 3.0l BMW M engine in any vehicle under development or even in the next after that. That would be a specific power greater than the McLaren MP4-12C. That is simply not realistic any time soon.

Again this has nothing to do with what is possible. It has to do with what is CHEAP and that is BMW's new middle name. Massive parts commonality to serve both the above average quick AWD family luxury grocery getter all the way to the "race bred" M cars. This is their road to CHEAP. Don't take my word for it - this has been presented in many a BMW investor presentation.

[Uli_HH]

Originally Posted by swamp2

I know the new M3 and M4 will perform. Nonetheless one can not deny there is just something wrong with a lightly massaged n54 with close to 500 hp in a 65-70k base M4 (guessing the M4 will have even more power than the M3 and will also exhibit engine "reuse" to maximize profit). I guess as long as the cars continue to dominate their classes I can't complain too much. Nonetheless small details like this make the cars undeniably less special and have me looking seriously outside the M brand for the first time in a long time.

100% agreed ... that´s the point in the engine issue ... I don´t beleave that the new M3/M4 in any kind would be an bad performer - performance would be better than any precessor !

BUT for me an M3 (until today) was an very special car and that not only meens performance wise ... I am ready to pay an much increased price for an car like an M3 because I get something special an unique ... less than 20% common part are an credo for the M-GmbH (until now) ... an the unique, special and fascinating engine is an important part (if not the most important!) of the Myth M ... I am not really willing to accept an simple "pimped" AG-engine in an M3/M3, what an S55 based on the N55 in any kind would be ... there could the N54/335i(tuning)-Fanboys could say what they want - they just don´t understand the Myth M ... it´s much more than hp, performance and sound !!!

Originally Posted by swamp2

Let's look at n55 being the base engine for the new M3/M3, specifically the bored vs. stroked issue for a larger displacement. I thought I may be able to conclude that the engine simply can not be bored alone to 3.2 liters, but this quick calculation does not quite show that, neither from pure geometric argument nor from a more engineering based argument. It almost shows it but not quite...

n55/n54
Bore: 84 mm
Stroke: 89.6 mm
Bore spacing: 91 mm
Displacement 2.979 l

Cylinder wall thickness between cylinders = 91 - 84 = 7 mm = .28". Just over 1/4 inch.

To get to 3.2 l (a rumored displacement) with bore change alone requires a bore of:

2*((3.2/2.979)*(84/2)^2)^(1/2)

Or 87.1 mm. Let's call it 87.

That would leave .15 inch of material between the cylinders. A shade more than 50% of what you can see in this picture (n54 block shown, these features are identical on the n55 block). Although this looks and feels too thin, engineering is not about look at feel. The stress in this portion of the engine will be roughly

σ = peak combustion pressure * (bore/2)/(thickness between bores)

(Note: This is the simplest thin walled cylinder approximation, which should be decent in this case.)

The peak combustion pressure (really rough estimate) is probably around 1000 psi (full load, high rpm). Anyone want to help me revise that estimate? This IS NOT BMEP, but peak dynamic combustion pressure.

Thus going from 3.0 to 3.2 liters by bore alone will increase the stress in this region by the same ratio as the wall thicknesses, nearly 200% in this case (x 1.86)!

The wall is certainly strong enough to handle a single combustion cycle. The limiting factor in design here is very likely "high cycle fatigue". This is just the repeated loading of the combustion cycle continuously weakening the material on the thin walled aluminum in this area. A practical limit for the allowable stress in typical aluminum alloys used for heads and engine blocks (say A356 alloy at an elevated temperature of 300 deg F) is in the 13000 psi range.

In the new 3.2 l hypothetical design the cylinder wall stress would be about 11000 psi. Very close the 13000 limit.

So in short, without sleeving, the n55 could likely enable a 3.2 l engine by bore increase alone. However, it appears to be producing a design very near fatigue limits. Thus, unlikely but not impossible.

My prediction for the engine is > 3.0 liter displacement and that will be gained by bore and stroke. I think that was also my prediction before this simple investigation...

As I've noted before even 400 hp from a 3 liter engine is already reaching the same hp/l as the Porsche Turbo. An additional reason I think the displacement must be going up.

First of all ... nice review!

But I simple don´t beleave that BMW/M-GmbH on the one hand would re-inforce the engine by puting reinforcement bars on the outside of the crank-shaft-housing and eventually on the engine block and on the other hand would reduce the thickness of the cylinder walls ... so increasing the bore of the engine for me is no suitable option to increase the displacement. Also if BMW is doing so, they need complety new pistons which would have nothing common with other engines ... no way much much too costly!

The only relativ cost effectiv way to increase the displacement of the N55 is to stroke it ... that this make less sence for an high-pressure and high-reving turboengine is clear.

Greets Uli_HH
P.S. ... but there are recent rumors, that the rumored 3.2 I6 could be the engine of choise for the coming M340i, which would have probably an much greater Hp-increase than current M...i models.

[swamp2]

Originally Posted by Uli_HH

100% agreed ... that´s the point in the engine issue ... I don´t beleave that the new M3/M4 in any kind would be an bad performer - performance would be better than any precessor !

BUT for me an M3 (until today) was an very special car and that not only meens performance wise ... I am ready to pay an much increased price for an car like an M3 because I get something special an unique ... less than 20% common part are an credo for the M-GmbH (until now) ... an the unique, special and fascinating engine is an important part (if not the most important!) of the Myth M ... I am not really willing to accept an simple "pimped" AG-engine in an M3/M3, what an S55 based on the N55 in any kind would be ... there could the N54/335i(tuning)-Fanboys could say what the won´t - they just don´t understand the Myth M ... it´s much more than hp, performance and sound !!!

Greets Uli_HH

Yes agreed right back at you!

It is funny how much BMW M USED TO promote 80% different parts on the M cars and REDLINE, REDLINE, REDLINE. Now it's highest price and parts bin cars... Oh well I still may buy one .

[NELSON.MLGB]

whatever happens， I still love my s65.

[m balla]

It could be possible to do 447/402 from a benzin version of the tri-turbo diesel design. I would more likely buy a 3.2 though because it has more potential. With those big of back tires I'm assuming higher compression w high boost so w a trick intake setup that improves flow modulation, I could foresee twin dual or twin triple scroll turbos as well. But with turbo lag that's where the third turbo comes in. Listening to the exhaust clips it sure seems like there is a lot flow at low rpms so not sure to compare it to n55 sound, triturbo diesel sound or if sounds similar to s63tu. It appears the cylinders have some room to bore outwards but reinforcing def w aluminum block.

[swamp2]

Originally Posted by m3alabama

Swamp I think we are both pretty much on the same page.

...my only point is I think bmw proved with the 1M that they already have the goods to reach 400 crank hp with 5-6 year old technology (n54) in a reliable fashion.

I'm not so sure we are on the same page. You keep repeating how easy it would be to get 450 hp from 3 liters. I suppose I agree with that in theory but in practice it takes much more than you admit (the points about everything outside of the block and heads - you seem to be ignoring)

Tuners may believe a n54/n55 is reliable with 450 hp but I guarantee BMW M engine engineers do not. Plain and simple.

As well BMW has simply not produced a factory reliable 400 hp with the n54/n55.

Originally Posted by m3alabama

kill some more parasitic losses from the lighter valvetrain and updates a few parts could probably achieve the 450 crank number.

In typical discussions about parasitic losses they are all after the crankshaft. Now for the very specialized topic about pre-crank or losses in the actual engine itself: You won't be making any appreciable gains (far less then 1%) from changes in the valvetrain.

We certainly do agree that a flat torque curve and linear power curve extending to around the 7k rpm range is very likely for the next engine.

Cheers.