M3 / M4 V6 Speculation

[mkoesel]

Originally Posted by Uli_HH

THAT HAS NOBODY SAID !!!

Only that an N55-based S55 with 3.3ltr. as rumored in german forums and 8.000U/min Redline is impossible ... and also that by an 3.0ltr.S55 8.000U/min Redline are not easy to reach.

Let me be more specific -

No one has established why the most obvious engine choice cannot be made to work. And frankly, no one can or will. Because we all know that an 8000 RPM 3L turbocharged I6 with ~450hp (or whatever the power target is) is far from technically impossible.

[turbolag]

Originally Posted by mkoesel

Let me be more specific -

No one has established why the most obvious engine choice cannot be made to work. And frankly, no one can or will. Because we all know that an 8000 RPM 3L turbocharged I6 with ~450hp (or whatever the power target is) is far from technically impossible.

Why not?

Honestly I'd rather take a higher redline over a 450hp engine...

[mkoesel]

^^^ I think you misread...

[CanAutM3]

Originally Posted by mkoesel

No need to remind me - I added a link to that thread earlier in my first post largely to highlight my position as well as that of others.

But you should hit the search function and brush up on you're history. That thread was not the first source of the rumors. We had discussed the V6 a number of times since it was first mentioned in an interview (with whom I forget - may have been Nitschke) long before. I have always considered it a red herring and still do. We'll know soon. If I am wrong you can expect me to admit it very publicly and give props to those who may have had more accurate predictions.

Don't take offense to my previous post, I was just nagging

I am with you, I also believe that an evolution of the N5X engine is the most probable approach for the M3/M4 from a rational point of view.

I guess it is my heart that is hoping for something more exclusive and special . The speculations towards a V6 do make sense though... However without having any strong substantiation behind them .

[mkoesel]

^^^

No offense was taken. I just figured that you were interested in facts so I wanted to point you in the proper direction.

The S55 will be plenty exclusive and special. Dare I say that, regardless of engine configuration, it will set the standard for turbocharged engine technology in performance applications.

[swamp2]

Good discussion here guys. I am enjoying it. I have four points to add.

1. Is the N55 bore truly bore limited? I don't think so but it is probably close. I posted about this with some very technical information back in July 2012 here. The S54 is the one we have heard has really thin wall thickness (minimal) between its cylinders and its piston speed is basically at the limit for a production engine (the limit 10+ years ago...). But of course it is an iron block!

N55
Bore: 84mm
Stroke 89.6
Cylinder spacing: 91mm
Wall thickness between cylinders: 7 mm
Piston speed at 7000 rpm: 69 fps / 21 m/s

S54
Bore: 87mm
Stroke: 91 mm
Cylinder spacing: 91mm
Wall thickness between cylinders: 4 mm
Piston speed at 8000 rpm: 80 fps / 24 m/s

S63Tü
Bore: 88.3 mm
Stroke: 89 mm
Cylinder spacing: 98mm
Wall thickness between cylinders: 9.7 mm
Piston speed at 7200 rpm: 70 fps / 21 m/s

Just for comparison sake the McLaren MP4-12C has:

Bore: 93mm
Stroke: 69.9 mm
Cylinder spacing: 108 mm
Wall thickness between cylinders: 15 mm
Piston speed at 8500 rpm: 65 fps / 20 m/s

The oversquare McLaren design also allows room for large valves which is always a packaging constraint and are required for high flow and high power.

Thus there should be room to have >=3.0l just from boring the N55. But is does seem unlikley. Additional displacement could also be added through stroke. I'm not quite sure if the addition of turbo charging specifically would preclude the rumored displacement and redline. I think that is a grey area all about how much BMW could tweak the performance vs. reliability envelope.

Ultimately here I conclude there is no "proof" that the rumored BMW displacement nor output forces our conclusion to I6 or V6 one way or the other.

2. 50-50 weight is absolutely non ideal for maximum performance. BMW needs to get over that mantra. 60-40 rear bias is significantly better. Either way a V6 would certainly contribute to maintaining 50-50 balance or at least prevent a nose heavy design which is highly undesirable.

3. Dr. Sound. 2nd request: Please post the audio clips you have analyzed that show very near 8000 rpm . I trust there is no fear of verification of your results. As you probably noted I initially over predicted the redline from recordings by at least 500 rpm. Having other forum members contribute to that process showed me my error. The 8000 rpm redline would indeed further point to a V6 but doesn't by itself prove a V6.

4. I firmly agree with the criticisms from Boss330 and others that all of the "fluff" about how great the new engine is and how great the car drives does not offer a single shred of evidence about its basic block configuration.

[solstice]

Anyone remember what technical information that came with the M5 "concept" if any? I'm just wondering what we can reasonably expect from Pebble Beach?

[Jason]

Originally Posted by solstice

Anyone remember what technical information that came with the M5 "concept" if any? I'm just wondering what we can reasonably expect from Pebble Beach?

Here is the F10 M5 Concept release from 2011:

http://f10.m5post.com/forums/showthread.php?t=511101

No HP figure was disclosed, but the engine setup (V8 twinpower turbo) was discussed. Also higher HP and fuel efficiency was talked about.

[chmura]

Originally Posted by solstice

Anyone remember what technical information that came with the M5 "concept" if any? I'm just wondering what we can reasonably expect from Pebble Beach?

Someone better take a pic of the tach at pebble beach.

[RMB]

I feel privileged to see so many people who are passionate about the upcoming BMW M3/M4. Everyone seems very knowledgeable and educated. Hell, I have two doctoral degrees and I am sure someone will say they have four. Either way , we will know shortly and everyone wants this to be a success. We all love BMW and we all feel that we know which direction they should go. However, the specialists at M also love BMW and they only want it to succeed. Whether it is a V6 or an I6, doesn't matter. I feel that they will make a spectacular engine and overall package, period! After all, the benchmark is the E92, so if they beat this it WILL be a success

[turbolag]

Originally Posted by mkoesel

^^^ I think you misread...

Yep, I did. Sorry.

Read it as impossible instead of far from impossible.

[solstice]

Originally Posted by Jason

Here is the F10 M5 Concept release from 2011:

http://f10.m5post.com/forums/showthread.php?t=511101

No HP figure was disclosed, but the engine setup (V8 twinpower turbo) was discussed. Also higher HP and fuel efficiency was talked about.

Thanks Jason, that's not bad, quite a few questions marks will be erased if we will get something like that.

One fluffy V6 argument that I put some weight on is that BMW is guarding the engine type this vigorously. Everyone expects an I6 when BMW elects six cylinders so it would surprise absolutely noone and not be worth while guarding IMO. The hp/tq and FI configuration I fully understand that they keep secret but not if it's an I6. If it's a V6 on the other hand it would be quite a bomb and worth guarding to the teeth, even with fake leaked pictures since it's truly something new for BMW.

The biggets argument for me though would be sharing parts of what's already been done with the M5 and all other current M cars except the outgoing E93.

[swamp2]

Originally Posted by RMB

I feel privileged to see so many people who are passionate about the upcoming BMW M3/M4. Everyone seems very knowledgeable and educated. Hell, I have two doctoral degrees and I am sure someone will say they have four. Either way , we will know shortly and everyone wants this to be a success. We all love BMW and we all feel that we know which direction they should go. However, the specialists at M also love BMW and they only want it to succeed. Whether it is a V6 or an I6, doesn't matter. I feel that they will make a spectacular engine and overall package, period! After all, the benchmark is the E92, so if they beat this it WILL be a success

I agree wholeheartedly!... With all but the last statement.

The benchmark for the car will be a variety of very high performance domestic and import cars who are all also going down the road of more power and in many cases less weight.

Are cars like the new Stingray, the Mustang Boss 302 Laguna Seca, the Camaro ZL1 and the GT-R truly competitors? Many of those are really just 2+2s but if not direct competitors they certainly are similar and are cross shopped. What about the 911? BMW made direct reference to competing against the 911 with the launch of the E92 M3. Perhaps the new Lexus RC F is a closer competitor which will probably be a 460 hp V8. The "classic" competitor the C63 will be getting the M177 twin turbo V8 with around 480+/- 20 hp. The current C63 AMG is no handling slouch either when compared to the current M3. BMW certainly knows and watches all this and more.

Since handling, suspension and tires seem to progress at a pretty even and natural pace both within and among brands, ultimately it is all about power to weight ratio and both may be big surprises for me and many of us here.

[swamp2]

Originally Posted by solstice

Thanks Jason, that's not bad, quite a few questions marks will be erased if we will get something like that.

Yes the somewhat emotional I6 vs. V6 thing will probably be settled. However, as noted just above we very likely won't get the two absolutely most important details, power and weight... We probably will get blacked out windows and no redline either...

[solstice]

As I said before I think this new M3 is going to be superb, IMO it has to if BMW in general and M in specific is going to keep their enthusiast status. They need a redemption car after the F10 and F30. The 3 and 5 are no longer the undisputed drivers cars in the segment and what to say about the new M5 and M6, powerful yes, but the massive weight, size and isolation is not helping generating much awe as the pinnacles of the ultimate driving machines. I can't wait to get my hands on one of these to see what BMW has come up with to create yet another udisputed king of it's segment and for the icon to live on and thrive. If a V6 serves them better in this quest I think there is no strong enough arguments to stop it.

[Dr. Sound]

Originally Posted by swamp2

3. Dr. Sound. 2nd request: Please post the audio clips you have analyzed that show very near 8000 rpm . I trust there is no fear of verification of your results. As you probably noted I initially over predicted the redline from recordings by at least 500 rpm. Having other forum members contribute to that process showed me my error. The 8000 rpm redline would indeed further point to a V6 but doesn't by itself prove a V6.

I dont´t know the exact second in the Video (3 minutes blasting...) any more but as I tried to measure again with the new 2013 Videos, I realized, the new production exhausts mounted to the F80 by now are washing out the combustions... the earlier louder and more defined exhausts were better for measuring!

Here is one of my old measurings:






And here I measured for testing and comparison my e46, just a second before shifting quite near to the max RPM:






Additional to the frequency calculating method of Audacity I counted the combustions by myself, as you can see.
Same result!
Before I could do this I had to uncompress the file and I added a low- and a highpass filter above and below the expected frequencies, including some safety distance, of course!
Always 19-20 combustions per 1/20th of a second!

I´m pretty sure I came quite close to the real thing that day!

[993]

Solved?

[993]

Close up

[Boss330]

Dr. Sound: Are you in any way related to Dr Thomas Schaller of BMW

Schall is a German word for sound... Just curious

[Tose111]

Lol Redline at 6000RPM. I'll Stay with my N54

Originally Posted by 993

Close up

[Boss330]

Originally Posted by 993

Solved?

Probably not since the speedo only shows 260km/h max. Just a std F30 instrumend display I would assume...

[Dr. Sound]

Jepp, early F80 mules were using F30 instruments! Means absolutely nothing! Photographed 2011/12 in the desert, I assume.

I personally have spoken to a guy who sat in a F80 in Munich, early 2013!
He drove to a redlight with his beautiful restored e36 M3, an F80 appeared besides and he was invited after a small conversation to take a seat!
He was too exited to remember the redline on the revcounter exactly... anywhere far above !! 7500, he said!
Redline, not end of scale!!

So... not solved, I think!