Latest BMW M4 Coupe F82 Spy Pics and Updated Info (Nearly 8000 RPM)

[swamp2]

Originally Posted by HouseMusicRules

I created a new graph assuming HP will be 450 (not 415) and I also put in a 50 lb-ft overboost feature similar to the E90/E92 335is for comparison.

As you can see this new power plant will be very potent, but definitely not a top end screamer as its predecessor as horsepower plateaus around 5,500 rpm. That sprint to redline wont yield any more power.

Almost seems as if BMW artificially created a high redline to appeal to the normally aspirated gearheads/magazines.

Regards,
HMR.

Excellent work, right in line with my predictions. However, I'm reasonably confident it will not offer an overboost feature.

As many of us have discussed prior, the numbers of 395 ft lb, approximately 415 hp and anywhere from a 7500-8000 rpm redline just are not consistent and possible together. Also BMW seems to have a decent track record (335i, 1M, F10 M5, etc.) of underrating. This M4 will be one and the same in that regard. I think they may rate the car around 425 hp but the likely actual crank hp will be in the range of 440-460. If these rumors on redline are true, and they do sound reasonable (and I always have a pretty high degree of trust in claims backed by southlight), I would guess a 7700-7800 rpm redline. It surely will not be ≥8000 rpm.

No doubt about it, the car will feel a bit flat above 6000 rpm compared to the current engine. However, flat with 10% more hp is not so terrible. Sure I'd prefer to not have this engine characteristic given such a choice.

Lastly I am 100% confident that this car despite the shape of its torque and power curves when above about 6000 rpm the former is falling fast and latter table top flat, will still only achieve maximum acceleration when shifted precisely at redline. Generally speaking, as long as the power curve does not actually fall and as long as the gear choices are reasonable, shifting at redline is required for maximum acceleration. If anyone want to continue to doubt this I would be willing to prove it either with a detailed Excel chart showing wheel force vs. speed in all gears or with a physics based acceleration simulation. Both require a resonable assumption on the torque or power curve vs. rpm and I would use something right along the lines of the one from HMR.

[mkoesel]

Originally Posted by ASAP

I dont understand the comment... this is not engine dependent but turbo sizing dependent.

That is vastly oversimplifying the issue. In fact, the dependencies are many and the technical challenges are complex, but the fact of the matter is that it is physically possible to build a high revving turbocharged engine that makes peak power at the top end of the rev band.

It may be true that if you or I started with an off-the-shelf N55 and began swapping turbos and playing with the ECU, we are unable get max power at ~7900 RPM. But then that isn't what BMW is going to do. None of us know just what is in store for the S55 yet. All we know is there will be multiple turbochargers.

[Tåst]

Originally Posted by Mak135i

Without getting in to the engineering and science behind the engine, can somebody explain why a 7700 RPM redline or a 6000 RPM redline matter if the car is making the same power at the lower point and indeed making more torque? I know the beauty of a NA engine is that the power keeps rising all the way (or very very close) to the limiter but in FI that's not the case and we know the new M3/M4 will be FI.

Thanks

Engine need more boost to make same power on 6000rpm than engine which rev 7700rpm, that means more lag, of course is more economical make power and torque on lower revs and making engine which is low revving not cost that much, thats why tc engines not rev so high than naturally aspirated, but now times has change.

Of course engine which have nice almost flat top end power curve is more easily to drive than engine which redline is 6000rpm and power rises very fast---> hard to find balance whit grip.

[CanAutM3]

Originally Posted by swamp2

Excellent work, right in line with my predictions. However, I'm reasonably confident it will not offer an overboost feature.

As many of us have discussed prior, the numbers of 395 ft lb, approximately 415 hp and anywhere from a 7500-8000 rpm redline just are not consistent and possible together. Also BMW seems to have a decent track record (335i, 1M, F10 M5, etc.) of underrating. This M4 will be one and the same in that regard. I think they may rate the car around 425 hp but the likely actual crank hp will be in the range of 440-460. If these rumors on redline are true, and they do sound reasonable (and I always have a pretty high degree of trust in claims backed by southlight), I would guess a 7700-7800 rpm redline. It surely will not be ≥8000 rpm.

No doubt about it, the car will feel a bit flat above 6000 rpm compared to the current engine. However, flat with 10% more hp is not so terrible. Sure I'd prefer to not have this engine characteristic given such a choice.

Lastly I am 100% confident that this car despite the shape of its torque and power curves when above about 6000 rpm the former is falling fast and latter table top flat, will still only achieve maximum acceleration when shifted precisely at redline. Generally speaking, as long as the power curve does not actually fall and as long as the gear choices are reasonable, shifting at redline is required for maximum acceleration. If anyone want to continue to doubt this I would be willing to prove it either with a detailed Excel chart showing wheel force vs. speed in all gears or with a physics based acceleration simulation. Both require a resonable assumption on the torque or power curve vs. rpm and I would use something right along the lines of the one from HMR.

Agree. I also believe that this engine will require shifting at redline in most gears.

What will be interresting is that, with such a flat power band, there should not be any drop in acceleration when shifting from one gear to another. Essentially having "450hp" available at any road speed. Further enhanced by the seamless shifts of DCT, the acceleration curve should be very smooth, progressively decreasing with road speed. As a comparison, with the peakier power curve of the S65, the wheel torque significantly drops with each gear change, yielding a "staircase" acceleration curve.

[Needsdecaf]

Originally Posted by ASAP

I dont understand the comment... this is not engine dependent but turbo sizing dependent. If the turbo can't hold boost past a certain rpm, it's useless to wind it out that far as you are actually losing performance. There is no way that they can size a turbo (whether 1,2 or 3) to be high revving, torquey and very responsive. Then comed the problem of gearing it right to take advantage of the spool... this would feel very weird if this thing really revved to 8k.

So it's very weird that the McLaren MP4 revs to 8500?

Numbers are just numbers without the context of the whole picture. FI engines can be sized to run to high RPM, just depends on the configuration of the turbos, etc.

The S55 will have at least two turbos, and who knows what kind of technology behind them. Since BMW is moving hard toward single twin scroll turbos on their I6's, this is a significant departure and can't be overlooked in light of the "close to 8,000 RPM redline" claim.

Most turbo engines on the road are low redline simply because they can be, and because it's cheaper to do so. Resources are not blown simply to make a number in Top Trumps. If a car meets targets for performance and economy, then a redline point is pretty pointless. Let's face it. 99% of drivers out there don't rev their car hard on purpose.

[Needsdecaf]

Originally Posted by pseto

+1 electric tri-turbo M3/M4 with near 8k RPM. BMW filed for the patent a while ago

http://f80.bimmerpost.com/forums/sho...d.php?t=597327

Paul:

With BMW going to single turbos on most of their I6 engines, I can't imagine a tri-turbo engine with electric motor. I would more envision this motor with one conventional twin scroll turbo, and one with this electric assist. It would make sense for a small twin scroll to be paired with a larger electric assist turbo, as that would minimize lag all the way around.

The tri-turbo setup as shown in the monster diesel is to get around issues that would be solved by having the electric motor.

Here's hoping...although warranty might be nightmarish!

[Needsdecaf]

Originally Posted by car7

It was 3 sentences. Americans shouldn't complain about the move from a 8-cyl to a 6, because bmw never was about v8s. The s65 is a very nice sounding engine. But it is way to slow and way to inefficient. You could always buy a camaro, because there is no point in whining about something that's gonna happen regardless if you like the s65. The next m4 is gonna make the m3 look outdated in every way.

What is BMW about? When was the last time an M5 had an I6? It's been, how long, 15 plus years?

The M3 has been a 4, 6, 6, 8 and now back to a 6. So 6 is certainly the norm for the M3, but not the rule. And if you want to stay "pure" you should be saying it should be a 4.

The M5 has been a 6, 8, 10 and now back to 8.

Don't forget, BMW also said "no turbo M cars, no AWD M Cars, no M SUV's and no automatic transmission M Cars" as well. Times change, technology changes and so does philosophy, etc.

I am no luddite, but the S65 is an amazing engine with a lot of soul, and while I understand why BMW is making the move they are, it doesn't mean that I don't bemoan the loss of one of the greatest V8's ever.

[Needsdecaf]

Originally Posted by mkoesel

That is vastly oversimplifying the issue. In fact, the dependencies are many and the technical challenges are complex, but the fact of the matter is that it is physically possible to build a high revving turbocharged engine that makes peak power at the top end of the rev band.

It may be true that if you or I started with an off-the-shelf N55 and began swapping turbos and playing with the ECU, we are unable get max power at ~7900 RPM. But then that isn't what BMW is going to do. None of us know just what is in store for the S55 yet. All we know is there will be multiple turbochargers.

Thank you for bringing some proper perspective! Too many people thinking along the lines of what happens when you take an existing engine and play with it via a tuner. Much more is possible when you are starting with a relatively clean sheet and the resources of a full manufacturer.

[Tåst]

Originally Posted by Needsdecaf

What is BMW about? When was the last time an M5 had an I6? It's been, how long, 15 plus years?

The M3 has been a 4, 6, 6, 8 and now back to a 6. So 6 is certainly the norm for the M3, but not the rule. And if you want to stay "pure" you should be saying it should be a 4.

The M5 has been a 6, 8, 10 and now back to 8.

Don't forget, BMW also said "no turbo M cars, no AWD M Cars, no M SUV's and no automatic transmission M Cars" as well. Times change, technology changes and so does philosophy, etc.

I am no luddite, but the S65 is an amazing engine with a lot of soul, and while I understand why BMW is making the move they are, it doesn't mean that I don't bemoan the loss of one of the greatest V8's ever.

V8 Bmw´s are come only "modern era" cars. I6 has lot more history, E9 3.0 CSL , E24 635Csi, E28 M5, E28 M535i, M1 M88, E34 M5, E36 M3, E46 M3 and now F82 M3.

[bimmerjph]

Originally Posted by CanAutM3

Not sure where you are getting this from

BMW has been making great V8s throughout its history.

Eh not really. Their first V8 was the OHV V8 from the 50's in 60's which was meh. Then there was a 25ish year gap with no V8's made. In the early 90's BMW introduced the M60, which wasn't really that powerful for its size. I mean it wasn't a bad engine, it just wasn't great. Then the M62 came out, the only real performance difference is that had more torque. The S62 was a great engine however. Very sporty yet civilized. The next V8 was the N62, which was a good engine. It did have a weird characteristic though, it had massive throttle lag on start-off (and I mean massive throttle lag). I have driven all sorts of BMW's and never experienced that amount of lag. The next V8 was the S65, which actually powers God's chariot. Then we have the N63, which as we all know is very powerful. However its not very exciting.

So BMW isn't really a renowned maker of V8's. They have made two greats, one good, the rest are meh. Where as they have a much more consistent record with their inline 6's. I would have to agree with the statement that BMW has never really been about V8's.

[Judah]

Originally Posted by mkoesel

That is vastly oversimplifying the issue. In fact, the dependencies are many and the technical challenges are complex, but the fact of the matter is that it is physically possible to build a high revving turbocharged engine that makes peak power at the top end of the rev band.

It may be true that if you or I started with an off-the-shelf N55 and began swapping turbos and playing with the ECU, we are unable get max power at ~7900 RPM. But then that isn't what BMW is going to do. None of us know just what is in store for the S55 yet. All we know is there will be multiple turbochargers.

Agreed, like I said before. I think we are going to see something new. Possibly something along the lines of an electric assist to defeat lag in conjunction with a turbo sized for top end breathing....

[solstice]

I dunno, I've owned a handful of turbo cars and driven many more over the last 25 years and none have built linear power as rpms raises towards the redline. Is it possible? Probably but can anyone here say that they have driven such a car and point us to one?

Also, keep in mind why BMW is going FI and the thirst of an engine running peak boost at 8k rpm...

[Judah]

Originally Posted by solstice

I dunno, I've owned a handful of turbo cars and driven many more over the last 25 years and none have built linear power as rpms raises towards the redline. Is it possible? Probably but can anyone here say that they have driven such a car and point us to one?

Also, keep in mind why BMW is going FI and the thirst of an engine running high boost at 8k rpm...

I too have owned and driven plenty of turbo cars since my 1986 Starion and for the most part you are right but none of them incorporated the tech I think we are about to see in the M3/4 motor.

[solstice]

Deleted,wrong thread.

[ASAP]

Originally Posted by mkoesel

The only reason to do it is if the car is faster by letting the engine rev to ~8k. This would mean one of two things:

- The engine is still capable of making more power at that RPM.

- The engine's power peak comes before 8k RPM, but the decrease in power above that point is offset by targeting a higher RPM for the next gear change.

One thing we can be sure of is that BMW will not produce an engine that revs to nearly 8K RPM at the expense of performance.

Yes... can't argue anything here. Except the first one is nearly impossible without an amount of work that BMW will not put into a 60K car.

Originally Posted by mkoesel

That is vastly oversimplifying the issue. In fact, the dependencies are many and the technical challenges are complex, but the fact of the matter is that it is physically possible to build a high revving turbocharged engine that makes peak power at the top end of the rev band.

It may be true that if you or I started with an off-the-shelf N55 and began swapping turbos and playing with the ECU, we are unable get max power at ~7900 RPM. But then that isn't what BMW is going to do. None of us know just what is in store for the S55 yet. All we know is there will be multiple turbochargers.

Sure, it's physically possible... look at stroked evo's that rev to 11k with large turbos. The problem there is, the motor is very laggy and not torquey at all making responsiveness and daily driving near unbearable. The only way this is remotely possible is playing with turbo sizing and running two sequential turbos or some sort of tri setup that we do not know of. Any way you look at it... I highly doubt BMW will put that much effort to solve such a difficult challenge into this motor.

[ASAP]

Originally Posted by Needsdecaf

So it's very weird that the McLaren MP4 revs to 8500?

Numbers are just numbers without the context of the whole picture. FI engines can be sized to run to high RPM, just depends on the configuration of the turbos, etc.

The S55 will have at least two turbos, and who knows what kind of technology behind them. Since BMW is moving hard toward single twin scroll turbos on their I6's, this is a significant departure and can't be overlooked in light of the "close to 8,000 RPM redline" claim.

Most turbo engines on the road are low redline simply because they can be, and because it's cheaper to do so. Resources are not blown simply to make a number in Top Trumps. If a car meets targets for performance and economy, then a redline point is pretty pointless. Let's face it. 99% of drivers out there don't rev their car hard on purpose.

I am asking once again what the point of a turbo motor revving to 8K is? I've spoken to engineers on this subject and they agree. Sure the Mclaren can do it, except it has a much larger displacement high revving V8 than the S55 will have allowing it to take much better advantage of the power band. In addition; that is a $300K exotic, this won't happen on a modified N55, you can forget about it...

[Judah]

Originally Posted by ASAP

Any way you look at it... I highly doubt BMW will put that much effort to solve such a difficult challenge into this motor.

I disagree, I think this is exactly what they are doing. BMW isn't a small aftermarket tuner. Remember, the M3 is generally the vehicle in which new performance tech is introduced then later trickled down.
SMG
SMG 2
DCT
Special Diffs
Double Vanos ...... etc.

[mkoesel]

Originally Posted by ASAP

I highly doubt BMW will put that much effort to solve such a difficult challenge into this motor.

Well, we'll have to wait and see. No need to debate it further then - you'll soon have your answer as to why the engine rev's to near 8k (if indeed it will, which I do believe at this point).

"We will surprise you with this car." - BMW M (forgot the specific person's name)

Based on how much skepticism and doubt exists even as more and more information comes forth, I fully expect that it will indeed surprise a lot of us. Heck, I will admit to being caught off guard if the weight truly ends up 3300 lbs or less.

[mkoesel]

Originally Posted by ASAP

I am asking once again what the point of a turbo motor revving to 8K is?

Or, one more thing. You could buy this:

http://www.ebay.com/itm/HorsepowerFr...-/140090291662

And try it out yourself. Maybe that would help explain? I kid. But only sort of.

[Remonster]

Originally Posted by Mak135i

Without getting in to the engineering and science behind the engine, can somebody explain why a 7700 RPM redline or a 6000 RPM redline matter if the car is making the same power at the lower point and indeed making more torque? I know the beauty of a NA engine is that the power keeps rising all the way (or very very close) to the limiter but in FI that's not the case and we know the new M3/M4 will be FI.

Thanks

A higher redline lets you get away with shorter gearing so the car can accelerate more quickly while hitting the same maximum speed in each gear. For example you could use a 4.0 rear end ratio on a car with an 8,000RPM redline, but if you used that same ratio on a car with a 6,000RPM redline (with everything else being equal) you would constantly be shifting gears. STIs are a good example of this, at stock power levels their gears are already very closely spaced which makes them really fun to drive but if you add more power you end up constantly shifting. This isn't as big of a problem with a DCT transmission but it can be annoying for manual drivers.

I think the 'problem' with US-spec STIs is they come with a 2.5 liter motor that redlines around 7,000 while the JDM STI has a 2.0 liter that revs out to 8,000. I think they may be using the same gearing on both cars, that would explain why the US cars feel like they're constantly running into their rev limiter.

[ASAP]

Originally Posted by mkoesel

Well, we'll have to wait and see. No need to debate it further then - you'll soon have your answer as to why the engine rev's to near 8k (if indeed it will, which I do believe at this point).

"We will surprise you with this car." - BMW M (forgot the specific person's name)

Based on how much skepticism and doubt exists even as more and more information comes forth, I fully expect that it will indeed surprise a lot of us. Heck, I will admit to being caught off guard if the weight truly ends up 3300 lbs or less.

3.0L S55 Motor revving to 7K, at most 7200 - mark my words

Originally Posted by mkoesel

Or, one more thing. You could buy this:

http://www.ebay.com/itm/HorsepowerFr...-/140090291662

And try it out yourself. Maybe that would help explain? I kid. But only sort of.

Whatever happened to those guys? lololol

[mkoesel]

Originally Posted by ASAP

3.0L S55 Motor revving to 7K, at most 7200 - mark my words

How about a friendly wager then? Shall we say the winner donates an agreed upon sum to a worth charity in the forum's name?

Whatever happened to those guys? lololol

Unfortunate, isn't it? Still powered some crazy fast high revving turbocharged S54s though. Maybe there's no market in that anymore, I don't know. But I'll bet BMW can figure out how to pedal their latest wares to eager enthusiasts.