BMW 2014 F80 M3 S55 Engine (Turbo Inline 6) Physically Exposed!

[swamp2]

Originally Posted by hwelvaar

So don't :-)
And even if the engines might be somewhat comparable, their target audience isn't. Most M3 drivers use their car as daily driver. Most Ferrari drivers use their car as weekend/track fun toy.

I only said one should not make "too direct of a comparison". Although the differences are abound there are many similarities and in many cases there is a valid reason to use BMW M and Ferrari in the same sentence or comparison.

You do know how many folks regularly track their BMWs? I'm sure you realize that there are many Ferraris that are daily drivers. Volume and cost and the biggest differences

Originally Posted by hwelvaar

But the engine is one of many ingredients that make an M car. So the next M3 still has a chance to feel like an M. We'll have to wait and see...

Yes, hopefully in additon to abandoning long held design principles BMW will stop it with the 50-50 weight distribution nonsense and move to a more effective rear weight bias, which will improve many aspects of handling

[swamp2]

Originally Posted by NISFAN

swamp2 you keep bringing up Turbo lag.....can you define what this means to you?

What it means to me? I think it means the same thing to most enthusiasts.

Turbo lag is the delay in engine and vehicle response due to low engine torque. The engine is only making a fraction of its potential torque/power at a given rpm and throttle because the turbo takes some time to gain rpm to one where there is significant flow and pressure being produced. Thus the engine response and vehicle response lags the throttle response. This happens whenever the throttle is moved significantly and rapidly from low rpm. It affects raw vehicle performance and requires certain techniques to avoid or drive around its effects on the track. Perhaps equally important it negatively affects the feel of the vehicle; its immediacy and direct connection to the driver via his right foot.

Traditionally, all M vehicles have enjoyed not only good throttle response but excellent throttle response.

Some (more non-enthusiasts) in my opinion, claim that recent BMW efforts with their twin turbo in the 335i have eliminated turbo lag. Although they have done a good job it is still very present.

[NISFAN]

I disagree, to most enthusiasts Lag is the revs at which the Turbo is capable of producing boost. Technically known as Boost threshold.

Lag technically is the delay between throttle application and power delivery when the engine is in the boost threshold region.

The fact that the new M3 has at least 2 turbo's sequentially set up, and a very short plumbing through an water/air intercooler, to me means that it will be significantly better than a 335i in both boost threshold and Lag terms.

The major plus with a Turbo is you have a massive torque band.

When you undertand the real term of LAG, an NA engine has LAG ALL THE WAY TO REDLINE, at it never has that boosted torque increase.

Unfortunately you always seem to get NA or Turbo enthusiasts. It is usually one or the other as a preference.

[swamp2]

Originally Posted by NISFAN

I disagree, to most enthusiasts Lag is the revs at which the Turbo is capable of producing boost. Technically known as Boost threshold.

No backwards, first lag is the phenomena, not the revs (as you explicity state) and it is not the rev range when "boost" is produced but the phenomena when "boost" is not being produced but being requested.

Originally Posted by NISFAN

Lag technically is the delay between throttle application and power delivery when the engine is in the boost threshold region.

That's closer to what I said and mostly correct.

Originally Posted by NISFAN

The fact that the new M3 has at least 2 turbo's sequentially set up, and a very short plumbing through an water/air intercooler, to me means that it will be significantly better than a 335i in both boost threshold and Lag terms.

No one knows the exact quantity, arrangement, size nor much else about the new cars FI system. The biggest variable will be the presence or absence of some sort of electric turbo or other lag reducing technique.

Originally Posted by NISFAN

The major plus with a Turbo is you have a massive torque band.

Not quite. The S65 has one of the broadest and flattest torque bands around. With a good turbo you get more torque at low rpms, good from a dig or for pulling stumps but not what makes a car the most exciting nor the most potent at the track. Turbos then generally can not keep up their performance to a very high redline thus their band width suffers.

Originally Posted by NISFAN

When you undertand the real term of LAG, an NA engine has LAG ALL THE WAY TO REDLINE, at it never has that boosted torque increase.

That's nonsense. Anyone who says that a very sporty engine like the S65 suffers from lag is utterly confused about lag.

Originally Posted by NISFAN

Unfortunately you always seem to get NA or Turbo enthusiasts. It is usually one or the other as a preference.

Agreed.

[ocso1606]

Thats....gonna be a fun car!!

[Remonster]

Originally Posted by NISFAN

I disagree, to most enthusiasts Lag is the revs at which the Turbo is capable of producing boost. Technically known as Boost threshold.

Lag technically is the delay between throttle application and power delivery when the engine is in the boost threshold region.

The fact that the new M3 has at least 2 turbo's sequentially set up, and a very short plumbing through an water/air intercooler, to me means that it will be significantly better than a 335i in both boost threshold and Lag terms.

The major plus with a Turbo is you have a massive torque band.

When you undertand the real term of LAG, an NA engine has LAG ALL THE WAY TO REDLINE, at it never has that boosted torque increase.

Unfortunately you always seem to get NA or Turbo enthusiasts. It is usually one or the other as a preference.

No, I think most people think of lag as the time between pressing the pedal and reaching full boost. Boost threshold is a different issue and I have seen some people talk about that when they use the term lag, but I think we can all agree that, since BMW's current turbo engines can hit full boost by like 1,500RPM, this is a non-issue. I like to stay in really high gears, if I am about to stop at a red light and it changes to green when I'm rolling at about 5mph, I'll probably stick it in 3rd or even 4th gear and the N55 has absolutely no problem pulling cleanly from way down low.

Both my N55 and the N54 have perceptible lag, they're more responsive than almost any other turbocharged engine ever produced but they are still miles away from the responsiveness of a naturally aspirated motor. This isn't such a huge deal, but on an M car I expect very granular throttle control mid-corner and my 135i is seriously lacking in this department compared to the E90 M3 my brother used to have.

[bimmerjph]

Originally Posted by swamp2

Certainly these are the rules by which companies are run. My point is not that this is bad and I have stated that. It can however, lead to compromises that are not necessarily in the best interest of the educated/enthusiast consumer. This point of view simply allows us to better understand the sources for BMW decisions. Folks like to talk (and romanticize) about tradition, engineering, motorsport, etc. when in fact things are the way they are based primarily on the bean counters. It's not sexy, but it is fact. As I also pointed out in prior posts things are different at other companies. Audi, Porsche, Lamborghini, Ferrari, GM and Ford are all continuing to to build supercharged and normally aspirated sports cars. Those cars are developing more specific power, more absolute power and doing so at increasing redlines. They are even delivering improved fuel efficiency. Although I agree one should not make too direct of a comparison between Ferrari and BMW, the S65 is practically straight out of Maranello and that is why it is such a special engine. It represents the pinnacle of BMWs prior M engine concepts of relatively low displacement, high specific and high absolute power primarily through high redline. The last key component of M engines has been fantastic throttle response. This great trend has now halted and will almost for sure be reversing to some degree. As already discussed BWM M is abandoning tradition. I certainly agree 100% that it is an unanswered question as to what extent a lower redline and potential turbo lag will detract from the engine and the car.

Some of these other companies are making decisions less by the bean counter and more from a marketing/tradition/engineering/enthusiasts perspective. Sure they will be cutting costs as well, but they just are not as obsessed with cost as BMW.

Also, even though I just said it a few posts ago, I'll say it again, I strongly believe that IF the cars has no noticeable turbo lag, it will be a hell of an engine, a hell of a car and almost for sure a class leader as it always had been.

One beauty of engineering, a distinctly human endeavor, is that there is often so many alternate solutions for a problem which is not specified so strictly and precisely to only allow a single correct solution. Let's hope BMW M has a beautiful and elegant solution to the problem stated (mandated) by the bean counters!

I think the problem is that BMW is betting the up and coming generation of buyers actually care about the environment. We don't really. At my school there are maybe 3 or 4 people that give even a slight damn about CO2 emissions. I could seriously go on for hours about the reasons i think why BMW is letting the efficient dynamics program take its balls, but in truth no one but the Quandts and the Board know. But at least they have said that the Naturally Aspirate car is not dead yet, so maybe there is hope in the distant future.

[NISFAN]

Originally Posted by bimmerjph

I think the problem is that BMW is betting the up and coming generation of buyers actually care about the environment. We don't really. At my school there are maybe 3 or 4 people that give even a slight damn about CO2 emissions. I could seriously go on for hours about the reasons i think why BMW is letting the efficient dynamics program take its balls, but in truth no one but the Quandts and the Board know. But at least they have said that the Naturally Aspirate car is not dead yet, so maybe there is hope in the distant future.

BMW is from a European country, all of which have signed up for the Kyoto agreement. That means reducing emissions.
Would be a stupid business model to ignore over 50% of their market. In fact BMW are actually increasing market share in Europe because they are the leaders in CO2 reduction.
Manufacturers in Europe also have to reduce their average CO2 emissions below set targets, otherwise recieve fines. The M3 is not exempt.

[NISFAN]

Originally Posted by swamp2

No backwards, first lag is the phenomena, not the revs (as you explicity state) and it is not the rev range when "boost" is produced but the phenomena when "boost" is not being produced but being requested.

Yes, exactly....people expect boost from idle to red line.

Where they feel the biggest deficit of boosted power is just off idle. This is not lag, this is a Turbo below it's boost threshold. i.e. in a rev range where the turbo is not getting enough exhaust energy to produce positive boost. If the engine were kept below this threshold boost would never be produced.

Originally Posted by swamp2

No one knows the exact quantity, arrangement, size nor much else about the new cars FI system. The biggest variable will be the presence or absence of some sort of electric turbo or other lag reducing technique.

This statement proves how common the mis-labeling of 'LAG' is. This electric tri turbo arrangement will be to reduce boost threshold, not to counter lag, but as the common misconception is that lag is boost threshold it gets labelled as an anti lag device.

Originally Posted by swamp2

Not quite. The S65 has one of the broadest and flattest torque bands around. With a good turbo you get more torque at low rpms, good from a dig or for pulling stumps but not what makes a car the most exciting nor the most potent at the track. Turbos then generally can not keep up their performance to a very high redline thus their band width suffers.

Right I need to explain this better. Lets say you take an S65 engined M3 and turbo charge it. You leave everything about the engine exactly as it is, cams, compression ratio, everything. But you now have a large sized turbo that comes on boost (the boost threshold thing once again) at 4000rpm, and runs hard til the redline.

Now if you were to drive this Turbo S65 M3 you would get used to the intoxicating power that the turbo produces. After a few hours behind the wheel you would start to notice the how poor the response is below 4000rpm. This is your same beloved S65 but without boost, that seemed to have a lovely spread of torque, but now feels flat un boosted.

This is what I mean, a Normally aspirated engine has lag all the way to the red line, as it never gets that high torque boost hit.

Originally Posted by swamp2

That's nonsense. Anyone who says that a very sporty engine like the S65 suffers from lag is utterly confused about lag.

Make sense now?

[mkoesel]

Originally Posted by swamp2

Focusing on R&D instead of production is the exact reason why you would come to an incorrect conclusion about the TOTAL cost the engine choice.

swamp, you may have missed my second post above - I absolutely did address the production costs.

The bottom line is that no matter what costs we are talking about, having two engines that provide the same power output is going to cost more than having just one. I don't think that point is really up for debate. It is elementary.

So, do you know how much these engines we are discussing cost to produce? Do you at least have relative figures, or estimates based on some hard data? If not I don't know how much sense it makes to debate that particular issue further.

Also the I6 will have less components then a similar FI V8. We are not talking a bit more production here but orders of magnitude more for the shared engine components spread among a great deal of cars including some of the base 3ers, BMWs highest volume vehicle.

The component count alone cannot be used as a basis to determine the relative costs of two engines (or any two manufactured goods). Quantities produced plays a huge role as well. Obviously the M engine, which will only be used in the M3/M4, at least for the near term, is going to see much smaller numbers than a V8 which is used in multiple models, and will be added to others soon (5 Series, X5, X6). Thus it is not a simple matter to determine the least expensive engine.

Again the I6 was chosen as the LEAST expensive solution that met the power and efficiency requirements, period.

And if that's true for the M3/M4, then it is true for all other BMW models too. Surely. So then, if the I6 wins on cost and efficiency alone, then logically it must be slated to replace the V8 as well. No other conclusion makes sense given your hypothesis.

And yet I'd all but guarantee that the I6 will not replace the V8. I'd put money on it in fact. So, if you allow yourself to believe the same then you must also admit that there are other factors at play here. And those factors, as I mention earlier, relate to marketing and branding concerns such as exclusivity and buyer perception. After all, BMW has been building M engines since the very inception of the brand which overlap in function with engines in their normal series vehicles. This is not likely to change any time soon in my opinion - but if it did you better believe that it would save BMW a heap of money. And that is why I cannot agree that a bespoken M engine is the cheapest route, nor for that matter do I believe that the development of the S65 and S85 were the cheapest way for BMW to get to the current generation 414hp M3 and last generation 500hp M5.

The S65 did not receive further developments because of cost - sure. We all know that. But when you make statements like this one:

"It absolutely is not the Government(s) that are causing BMW to majorly change engine platforms in M cars. It is higher profit through much higher part commonality."

You lose credibility in my eyes because you have never once demonstrated with hard numbers that it would be possible to produce a 450hp S65 that would lead to any profit whatsoever. In fact it may have led to a loss which easily disqualifies it from consideration. You have no proof that this is not the case, and the "it's all about money" argument falls flat for the reasons I stated above.

Furthermore, you seem to suggest BMW will be more profitable using an N55 based solution for the M3, but if that is the case then why did they ever move to the S65 and S85 to begin with? They had been successfully building engines based on series engine architecture from the beginning. Did they suddenly decide back in 2000 or so that they didn't want to be as profitable as they had been in the past? It doesn't add up.

To my trained eye, M Division is doing exactly what they have been doing all along - building special cars for enthusiasts based on their more pedestrian products for the masses, and with a good deal of major changes and upgrades to accomplish that goal. There is no fundamental difference this time around, and there is no new focus on money grabbing vs. providing a product that is true to the brand.

[mkoesel]

Originally Posted by Venom

I hope it's called the S55Tu Is there any word yet on the displacement of the inline block?

I don't think it will be called the S55Tu simply because the N55 was designed from the outset with Valvetronic. BMW added the Tu suffix to the S63, and later then N63, when those gained Valvetronic throttle operation. That upgrade won't be happening with I6 engine family, so there will be no need for the name change.

[NISFAN]

You make a lot of sense mkoesel

[Venom]

Originally Posted by mkoesel

I don't think it will be called the S55Tu simply because the N55 was designed from the outset with Valvetronic. BMW added the Tu suffix to the S63, and later then N63, when those gained Valvetronic throttle operation. That upgrade won't be happening with I6 engine family, so there will be no need for the name change.

I was under the impression that Technische Ueberholung designated an upgrade from the normal marque. The N54Tu =?= N54B30To (I think, I could very well be wrong) was the 1M's engine and AFAIK all that was different from the N54Oo (where Oo denotes high output) was the Overboost functionality in software, made possible by a better cooling system.

I do have a question for you. Do you think there is a possibility of a larger displacement I6? (I remember reading that the best size was .5L/cylinder for maximum output.)

for the intelligent reply

[swamp2]

Originally Posted by mkoesel

The bottom line is that no matter what costs we are talking about, having two engines that provide the same power output is going to cost more than having just one. I don't think that point is really up for debate. It is elementary.

No disagreement. Cost is the most significant factor, but as I mentioned previously factors related to luxury, prestige and cylinder count which demand V8s in certain vehicles are relevant. I think BMW believes that certain vehicles simply must have 8 cylinders to even sell. They obviously do not believe this is required for the new M3/4.

Originally Posted by mkoesel

So, do you know how much these engines we are discussing cost to produce? Do you at least have relative figures, or estimates based on some hard data? If not I don't know how much sense it makes to debate that particular issue further.

No I don't, I could probably make some reasonable estimates but it would take some work (actually found some information see next post...). A key point though is that the base 3er engine will share much in common with the M3/M4 engine. Much of the development work is already done! It it through this huge increase in volume that the part costs are driven way down, providing an engine of immensely lower cost than a model specific engine produced in very low quantities, say about 20k engines/year. The 3er volume is more like 400k/year. Do you see some immense cost savings in that kind of volume? If not you do not understand the

Originally Posted by mkoesel

The component count alone cannot be used as a basis to determine the relative costs of two engines (or any two manufactured goods). Quantities produced plays a huge role as well. Obviously the M engine, which will only be used in the M3/M4, at least for the near term, is going to see much smaller numbers than a V8 which is used in multiple models, and will be added to others soon (5 Series, X5, X6). Thus it is not a simple matter to determine the least expensive engine.

Sure there will be variation but a rod is a rod is a rod and similarly for a piston. Thus component count strongly correlates with entire assembly count. Furthermore each component requires time to assemble and and reduction in time means lower cost. Lastly is weight when displacement and cylinder count are lower the engine weight will be smaller thus raw materials will cost less and raw material is also a big part of manufacturing cost. All of these contribute to why a 4 cylinder is less expensive than a 6 and similarly a 6 vs. an 8 (again in a similar design at similar volumes).

There is simply no debate that a very high volume turbo I6 will cost less to produce than a similar turbo V8.

There is also no debate that an engine being produced to the tune of 400k/year will be less expensive than 20k/year.

Originally Posted by mkoesel

nor for that matter do I believe that the development of the S65 and S85 were the cheapest way for BMW to get to the current generation 414hp M3 and last generation 500hp M5.

The S65 was very easy to develop as it is absolutely the S85 with two cylinders lopped off. The S85 was indeed expensive to develop and to manufacture. The S65 was similarly expensive to manufacture. The very existence of such special motors as these indicate the changing philosophy of BMW M. That just can't be denied.

Originally Posted by mkoesel

"It absolutely is not the Government(s) that are causing BMW to majorly change engine platforms in M cars. It is higher profit through much higher part commonality."

You lose credibility in my eyes...

Uhhh, see charts above again on the major BMW material cost "offensive" and how common subsystems will be saving them money. How is the M3/M3 sharing much in common with a base 3er NOT an example of this?

If you think that there costs, specifically cost of their engine, are either staying flat or going up that is pure absurdity.

Originally Posted by mkoesel

Furthermore, you seem to suggest BMW will be more profitable using an N55 based solution for the M3, but if that is the case then why did they ever move to the S65 and S85 to begin with? They had been successfully building engines based on series engine architecture from the beginning. Did they suddenly decide back in 2000 or so that they didn't want to be as profitable as they had been in the past? It doesn't add up.

I'm beating a dead horse here. BMW M is becoming a different type of company. M brand dilution, Efficient Dynamics (for BMW M), less special engines, forced induction, etc. are all driven by less R&D (again see charts above) and more profit. BMW is not only increasing their sales and production volumes but they are increasing their profit as a percentage of revenue!

Originally Posted by mkoesel

To my trained eye, M Division is doing exactly what they have been doing all along - building special cars for enthusiasts based on their more pedestrian products for the masses, and with a good deal of major changes and upgrades to accomplish that goal. There is no fundamental difference this time around, and there is no new focus on money grabbing vs. providing a product that is true to the brand.

It is simple to oversimplify and that is what you are doing with the statements above.

If you think BMW M of 2015 is or will be the same as BMW M of 2000 either in terms of R&D, cost structure or key philosophies you are just wrong.

As BMRLVR points out should we really be surprised that companies are primarily driven by profit? Time to stop the romance...

[US///M3]

In line 6's are a thing of the past,there was a time when a lot of car manufacturers offered the inline 6 with M-B producing the most refined inline 6's.
Even Jeep quit making inline 6's about 10 years.
A short block engine is the way to go imo.

[US///M3]

Originally Posted by NISFAN

BMW is from a European country, all of which have signed up for the Kyoto agreement. That means reducing emissions.
Would be a stupid business model to ignore over 50% of their market. In fact BMW are actually increasing market share in Europe because they are the leaders in CO2 reduction.
Manufacturers in Europe also have to reduce their average CO2 emissions below set targets, otherwise recieve fines. The M3 is not exempt.

Is the Audi RS4/RS5 or BMW M5 exempt?

[swamp2]

Engine Costs (and price): (A continuation/expansion of comments above in my post #388)

According to BMWfans.info, which I believe is just data directly from BMW repackaged, a 2009 (no newer data) S65 motor costs about $22.5k, an N54 costs $13.5k. Now this is the cost to a consumer. We can not deduce actual cost to the manufacturer from this but we can get a rough idea. Obviously these consumer costs are much higher than actual cost as you can not have an engine that costs over $20k in car that has a base sticker cost of $58k. You also have both OEM and dealer profit margins included in these figures. This factor of almost 2 between the engines cost should not be surprising. The N54 is less expensive because (not counting the FI system):

• Has less parts
• Key parts are smaller
• Entire engine is lighter (293 lb vs. 330 lb)
• Last and most importantly - the volume produced is immensely higher

Obviously the turbo system and associated plumbing contribute to making the engine more expensive but this is far outweighed by the economy of scale.

Now we know the version of the N55 in the M3/4 will be fairly heavily massaged. Probably a different head, different turbos, more costly cooling system and maybe even some internals. This will raise its cost above the base engine. What I would be willing to guarantee is that the first digit of the total replacement cost of this new engine will be 1 not 2!

The twin turbo V8 from the X6 and 7er (again 2009) has a cost of $21.9k. It cost more than the N55 due to the same points above but the opposite:

• Has more parts
• Key parts are larger
• Entire engine is heavier (354 lb vs. 293 lb)
• Last and most importantly - the volume produced is much smaller

This should answer definitively why a V8 turbo is not in the M3. BMW M does not believe the V8 is required in the application for prestige nor to make the required power and the N55 based engine will be substantially less expensive.

An educated guess on what factor these consumer costs are compared to actual production costs is not easy. Thus I would offer a reasonable range. Call this a bounding argument. I think the total markup factor is between 2-4. Thus I would place the cost to BMW of the N54 somewhere in the $3.5k-$7k range (probably closer to the lower end). Similarly the cost of the S65 is likely in the range of $5.5k-11k. That means the likely savings of a N54 priced N55 (using N54 cost estimate) is about 100,000 x ($2k - $4k) or between $200-400 million. 100,000 is the rough production volume of the M3 over its lifespan. This does not account for the other vehicles that may get a slightly tweaked version of the M3/4 specific engine.

Development Costs:

I have seen multiple references (internet/google, nothing special/secret) that peg complete new engine development at a major OEM in the $1B dollar range. However, I have also seen more references that an entire vehicle development costs that much. I think the latter is much more accurate. $1B is a stinking lot of cash. That is $100k in salary and $100k in facilities for about 3500 workers working for 18 months... (typical new vehicle development time). An engine is however a truly major component of a new vehicle development. At the big OEMs a figure on the order of $100M is probably reasonable.

With these numbers I would revise my prior statements that the cost of the economy of scale likely dwarfs development costs. I think this is a very reasonable argument that for these particular engines, the savings from taking the M3/4 to an I6 from NA V8 are on the same order as the development cost of an entirely new engine. However, the development cost is largely a moot point since we are talking about a massaged N55 NOT an entirely new engine. Certainly though when considering the possibility of another vehicle specific M engine, possibly an evolved direct injected S65 vs. a massaged N55 we are clearly talking about hundreds of millions of dollars of savings in development and production. This is clearly THE primary reason why the car does not have an existing turbo V8 nor a totally new M specific engine.

I am open to anyone's estimates or data to revise these numbers. However, because of the bracketing and large range of the concluded figures it is probably a very reasonable figure. The number here is certainly not $1B and is also not only $10's of millions either.

[swamp2]

Originally Posted by NISFAN

Yes, exactly....people expect boost from idle to red line.

Where they feel the biggest deficit of boosted power is just off idle. This is not lag, this is a Turbo below it's boost threshold. i.e. in a rev range where the turbo is not getting enough exhaust energy to produce positive boost. If the engine were kept below this threshold boost would never be produced.

I don't see much harm in labeling this all lag. Lag comes from impeller inertia, friction, efficiency, load and plumbing losses. The boost threshold is simply an rpm range where flow does not produce significant turbo rpm, flow and pressure. Both create a perceived lag in throttle response and rapid onset of vehicle power feeling like some "extra" amount of throttle has been applied.

Originally Posted by NISFAN

This statement proves how common the mis-labeling of 'LAG' is. This electric tri turbo arrangement will be to reduce boost threshold, not to counter lag, but as the common misconception is that lag is boost threshold it gets labelled as an anti lag device.

It is also unknown if an implementation of and electric turbo charger (or perhaps supercharger) will exist on the car and it is also unknown if it will target lag or lowering of the boost threshold or both.

Originally Posted by NISFAN

Right I need to explain this better. Lets say you take an S65 engined M3 and turbo charge it. You leave everything about the engine exactly as it is, cams, compression ratio, everything. But you now have a large sized turbo that comes on boost (the boost threshold thing once again) at 4000rpm, and runs hard til the redline.

Now if you were to drive this Turbo S65 M3 you would get used to the intoxicating power that the turbo produces. After a few hours behind the wheel you would start to notice the how poor the response is below 4000rpm. This is your same beloved S65 but without boost, that seemed to have a lovely spread of torque, but now feels flat un boosted.

This is what I mean, a Normally aspirated engine has lag all the way to the red line, as it never gets that high torque boost hit.

Make sense now?

That is what I figured you meant anyway and of course it makes sense. It is however not a particularly lucid way of thinking about engine performance. Either way you slice it, it is better to not have lag. Also more power at any rpm is always better. These are nothing more than tautologies! One other very relevant point is that most production turbo engines are much smaller displacement than a competitive NA engine or the NA engine they have replaced. Typically to have a less expensive engine and to improve fuel economy. The makes them notoriously down on torque when not producing significant turbo pressure. Hence why turbo lag and rpm ranges outside of the boost threshold are more annoying.

[NISFAN]

Originally Posted by US///M3

Is the Audi RS4/RS5 or BMW M5 exempt?

No, but lower numbers so don't skew the figures too much in the case of M5?

Audi group make thousands of shit boxes so they don't have too much issue.

[hwelvaar]

Originally Posted by bimmerjph

BMW is betting the up and coming generation of buyers actually care about the environment. We don't really.

This sounds like redneck logic to me. How can one not care about the environment ?
That being said, I agree that it doesn't necessarily mean that each and every car has to become a green car.

[NISFAN]

Originally Posted by swamp2

I don't see much harm in labeling this all lag. Lag comes from impeller inertia, friction, efficiency, load and plumbing losses. The boost threshold is simply an rpm range where flow does not produce significant turbo rpm, flow and pressure. Both create a perceived lag in throttle response and rapid onset of vehicle power feeling like some "extra" amount of throttle has been applied.

Yes there is harm in collectively calling this lag. It means that engine builders are tackling a problem that shouldn't require the effort that goes into it.

Most anti Turbo protagonists whine about a low rev limit and that an M engine should have a high rev limit. Well turbo charging does not limit the revs. There are plenty of Nissan RB26 engines (inline 6, 2.6litre) revving to well over 10,000rpm Turbo charged, producing in excess of 600hp. You have to understand with those engines that the powerband only starts at 3,500rpm, but if driven correctly on a track, you would never go below 4000rpm so never out of boost threshold region. This concept is very sporty and such a rewarding sensation when you get it right in rif=ding that Turbo charged wave of power.....
.....but because all the NA enthusiast whining, engine designers are building low boost threshold twin /triple turbo systems with a compact rev range overall. Not fun to drive.

Originally Posted by swamp2

It is also unknown if an implementation of and electric turbo charger (or perhaps supercharger) will exist on the car and it is also unknown if it will target lag or lowering of the boost threshold or both.

A compressor driven fast enough to produce boost needs a MASSIVE amount of power (a supercharger requires in excess of 30hp to drive). A 12v system and dinky little electric motors are physically incapable of producing the power required....so you can discount ideas of an eletric supercharger right now. In fact I see this electric turbo concept as a free alternator driving system not the other way round. Garrett tried electric assisted turbo chargers years ago, fact is a Turbo needs to be spinning at over 100,000rpm in order to produce positive boost pressures. Assisting to 50,000rpm or so doesn't really warrant the additional expense and weight for the miniscule reduction in lag.

Originally Posted by swamp2

That is what I figured you meant anyway and of course it makes sense. It is however not a particularly lucid way of thinking about engine performance. Either way you slice it, it is better to not have lag.

I don't understand, all normally aspirated engines have lag from idle to redline....so to you a half and half engine is not acceptable?

A sporty set up turbo charged S65 would produce 4 litre S65 NA torque and power to say 3000rpm then produce 5.5 liter S65 type power and torque to the redline. You saying you would prefer just plain NA 4.0 litres all the way?

Originally Posted by swamp2

Also more power at any rpm is always better. These are nothing more than tautologies! One other very relevant point is that most production turbo engines are much smaller displacement than a competitive NA engine or the NA engine they have replaced. Typically to have a less expensive engine and to improve fuel economy. The makes them notoriously down on torque when not producing significant turbo pressure. Hence why turbo lag and rpm ranges outside of the boost threshold are more annoying.

I agree that Turbo engines are smaller displacement. That is why you need to design a Turbo engine from the start (and probably why Turbo S65 is no go). Torque is actually a product of length of stroke (leverage of the combustion power on the crank) so a torquey engine can be produced with smaller displacement. But ultimately, it is the gearbox that converts the engine torque to useful wheel torque. There are no doubts that a Formula 1 car is pretty fast, also in a straight line? F1 engines produce less torque than many family run abouts. Power is what counts, geared to produce the right torque at wheels.

All this aside I don't understand the debate on engines costing less. Of course ANY manufacturer will persue cheaper engines, doesn't mean they are selling the M power theme down the river.

And by the way, the reason all the others have dropped Inline 6 in favour of V6/8's .....this is to do with crash test performance. Much more difficult to stop a long engine from being pushed into the cabin area.

[US///M3]

Originally Posted by NISFAN

No, but lower numbers so don't skew the figures too much in the case of M5?

Audi group make thousands of shit boxes so they don't have too much issue.

That didnt make sense if you consider all the V8's BMW,M-B have in their 7 series/S class.