-=Hot|Ice=-
High-Rev Hero
AutoBlog said:
Current generation BMW M3 to be the last naturally aspirated M car — Autoblog
M3/M4 Current generation BMW M3 to be the last naturally aspirated M car
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The BMW M3 is a high-performance version of the BMW 3 Series, developed by BMW's in-house motorsport division, BMW M GmbH. M3 models have been produced for every generation of 3 Series since the E30 M3 was introduced in 1986.
The BMW M4 is a high-performance version of the BMW 4 Series automobile developed by BMW's motorsport division, BMW M, that has been built since 2014. As part of the renumbering that splits the coupé and convertible variants of the 3 Series into the 4 Series, the M4 replaced those variants of the BMW M3. Official website: BMW M
Current generation BMW M3 to be the last naturally aspirated M car — Autoblog
Beemer B773ER
Tire Trailblazer
Well I guess they decided to make it official so as to induce a mad scramble among the NA purists to get their hands on the last of an era M3.
I imagine it won't be long at all until the last naturally aspirated BMW is produced. The turbo technology of today is superior in every objective measure, there is almost nothing that a BMW TT engine can't compared to its naturally aspirated donor engine. The legendary BMW N52 engine is now being put to rest in favor of the TT4-banger, and by looking at the numbers and reading a couple of media reviews, it seems that BMW hasn't skipped a beat.
I ask this as an honest question since I lack the technical knowledge and experience, but what technical/mechanical/performance benefit does a high-revving motor provide over a forced-induction engine that is able to deliver torque at a relatively lower rpms?
I drive an N52 engine BMW 3er, and about a month ago I got to test-drive the new X3 powered by the N55 (N52+Turbo), and the engine was more response, power delivery was quicker and hence better acceleration, ...and if you believe BMW, the fuel economy figures are just as good (if not slightly better). What's there not to love about these new BMW Turbo engines?
I imagine it won't be long at all until the last naturally aspirated BMW is produced. The turbo technology of today is superior in every objective measure, there is almost nothing that a BMW TT engine can't compared to its naturally aspirated donor engine. The legendary BMW N52 engine is now being put to rest in favor of the TT4-banger, and by looking at the numbers and reading a couple of media reviews, it seems that BMW hasn't skipped a beat.
I ask this as an honest question since I lack the technical knowledge and experience, but what technical/mechanical/performance benefit does a high-revving motor provide over a forced-induction engine that is able to deliver torque at a relatively lower rpms?
I drive an N52 engine BMW 3er, and about a month ago I got to test-drive the new X3 powered by the N55 (N52+Turbo), and the engine was more response, power delivery was quicker and hence better acceleration, ...and if you believe BMW, the fuel economy figures are just as good (if not slightly better). What's there not to love about these new BMW Turbo engines?
Merc1
Premium
The only things I see that in a lot of real world testing BMW's engines don't live up to the fuel economy numbers touted. That said, on paper turbos are the solution I guess. Can't really argue with on the objective, but the subjective is where it doesn't cut it for some. The feel and sound of a motor like the one in the M3 is just unlike anything else. Ditto for the previous M5.
I'd argue/dare BMW to be different and keep the naturally aspirated thing going for just the M cars and turbo everything else. I guess that wouldn't be enough to erase various environmental concerns and appease certain governments.
I want an M3 or RS5 ---> I now have to act much quicker.
M
Beemer B773ER
Tire Trailblazer
Unfortunately for BMW, it's probably got just as much to do with emissions targets/regulations across various continents. They probably could have developed one more generation of NA engines and still comply with emissions regulations, but it seems like they bit the bullet and decided to not be behind the curve by waiting one more generation of vehicles. Add to this their new Efficient Dynamics persona, and how it would be absolutely unfeasible to invest in a M-exclusive line of NA engines, and you can see why they're going down the forced-induction route now.
As much as I was impressed and proud of BMW and M for staying true to their long-held philosophy of NA engines, there's just no feasible future for it....but you can bet your bottom dollar that M are doing their darnedest to give the new M5 characteristics very similar to that of an NA engine!
I guess the best way to compare what M do with the engine in the upcoming M5 is to compare it with Audi's RS Turbo engines and also AMG's. I'm sure each engine will still have a different 'personality' rather than simply all being boring turbo autobahn monsters.
coolraoul
Torque Titan
Turbo-tech has effects on the responsiveness of the engine, on the precision of the throttle-input (turbo kicking-in, even in a subtle and quick way, will never match a linear power-curve), and of course has an extremely dubious reliability as showed by modern diesel-engines and the very frequent 100.000kms-turbo (and injectors) replacements...
Ther crazy noise of a high-revving N/A engine nearing 8.000rpm will be sorely missed too.
And the real-life benefits in terms of consumption are far from what's promised on-paper.
The sheer power, immediateness of speed without need for lots of revvs, low-end torque on the other end, are arguments in favour of forced-induction.
Ther crazy noise of a high-revving N/A engine nearing 8.000rpm will be sorely missed too.
And the real-life benefits in terms of consumption are far from what's promised on-paper.
The sheer power, immediateness of speed without need for lots of revvs, low-end torque on the other end, are arguments in favour of forced-induction.
FC123
Quattro Commander
If nothing else, a larger rev range does open up the possibility for a wider powerband.
This video is quite famous: Dailymotion - m6board.com:BMW M6 vs Kleeman E55 AMG K4 - a Auto-Moto video
640hp 900nm E-class vs. standard M6 500hp 500nm, see what happens at higher speeds, the Benz' huge torque and slush box propels it of the line, whereas the M6 high rpm and F1 style gearbox will lend itself more to high speed acceleration.
martinbo
Staff member
There's been a lot of talk regarding the move from naturally aspirated engines to forced induction for BMW's M cars so I thought I'd offer my opinion in this thread.
It is true that the engineering techniques employing turbocharging are rapidly improving and that, surely, turbocharging is the optimal way forward for the next 5 - 10 years for performance cars. Turbocharging of smaller displacement engines enables low throttle load efficiencies in terms of fuel consumption and emissions whilst providing improved volumetric flow at higher throttle openings - all things considered of course. So, McLaren's new benchmark for turbocharged engines - the M838T - will use as little fuel as a similar naturally aspirated 3.8 litre engine at small throttle openings and yet, on boost, with wide-open throttle, will out perform a 4.5 litre naturally aspirated V8 in not only only power but more significantly torque.
So at low engine rpm with small throttle openings, the smaller displacement engine optimally performs its primary role on this side of the performance envelope perfectly: the reduction of fuel consumption and emissions in accordance with legislative requirements. But what they don't tell you is that at high throttle, high rpm scenarios turbocharged engines use as much fuel - if not more - as naturally aspirated engines of similar output capability. Put your foot flat and a turbocharged engine drinks the precious fuel like a dehydrated camel.
Why? Well it's quite straightforward: if you want the horses you must feed them. You simply don't get big power and big torque for nothing; you need the fuel burn in order to achieve the desired outputs. Sure, modern lean-burn direct injection coupled with high compression ratios do make for an improvement in economy but the results aren't as far apart as the press material may suggest. You'll be quite surprised to see how close a turbocharged engine will come to the comparable naturally aspirated engine in terms of fuel consumption when the dogs of war are unleashed.
Alright we say, so turbo'd engines still have the upperhand on their NA counterparts; they make more torque lower down, have better low speed economy & emissions and make as much power at the top end. Clearly, it's advantage turbocharging and so what's all the fuss about?
The fuss is about Throttle Response. The one thing that a turbo'd engine will never match (oh, they might come close) is the outright throttle response of a naturally aspirated petrol engine that receives an exact, and more importantly, instant dose of precisely the right amount of air flow relative to the throttle position. It's this immediacy that is ultimately missing in turbocharged engines as a result of the air having regulated passage through what is essentially an air pump. So the sensation is this: the throttle response is softer - hence the term - and from throttle off to throttle on there is a delay as the inlet air flow takes its cue from the flow of the exhaust gases.
Ok, so why is throttle response so important? It's all about maximising the control a driver has over the engine - and hence entire car - with the accelerator pedal. A little bit of throttle on gives you one reaction, a little bit of throttle off, another. FWD, AWD, RWD - it makes no difference - the fact is that a quicker reacting throttle gives the driver greater control over the dynamic attitude of the vehicle thus leading to a more rewarding driving experience. The driver is able to meter out exactly the right amount of throttle vs. steering input (remember that the two are connected by an invisible piece of string - what you do with the one affects, and is affected by, the other) and there is no better illustration of this put into practice than this epic video by our member, AdvEvo:
What he's gone and done - intentionally or unwittingly - for the viewers is a fabulous thing in this video of that paragon of throttle response: the M3 CSL. By mounting the camera in this position one can see the extent of the steering angle on the front wheels whilst also being able to hear how much throttle input is being made. Look at the steering angle, listen to the frequency and the accuracy of the throttle inputs and hopefully you'll have a much finer appreciation of the importance of throttle response.
Sure, turbocharging is closing the gap since the old days of the laggy, big blowers but it has some way to go still to matching the immediacy and precise control of a proper naturally aspirated engine. It is, and always will be, the most direct connection from the driver's foot to the driven wheels. It's what makes the cars in this zenith of natural aspiration, the M3, 911 GT3 RS, LF-A, 458 Italia and GTO unforgettable and irreplaceable.
Special thanks to André (AdvEvo) for his uiters heerlik YouTube channel. Miss that guy...
It is true that the engineering techniques employing turbocharging are rapidly improving and that, surely, turbocharging is the optimal way forward for the next 5 - 10 years for performance cars. Turbocharging of smaller displacement engines enables low throttle load efficiencies in terms of fuel consumption and emissions whilst providing improved volumetric flow at higher throttle openings - all things considered of course. So, McLaren's new benchmark for turbocharged engines - the M838T - will use as little fuel as a similar naturally aspirated 3.8 litre engine at small throttle openings and yet, on boost, with wide-open throttle, will out perform a 4.5 litre naturally aspirated V8 in not only only power but more significantly torque.
So at low engine rpm with small throttle openings, the smaller displacement engine optimally performs its primary role on this side of the performance envelope perfectly: the reduction of fuel consumption and emissions in accordance with legislative requirements. But what they don't tell you is that at high throttle, high rpm scenarios turbocharged engines use as much fuel - if not more - as naturally aspirated engines of similar output capability. Put your foot flat and a turbocharged engine drinks the precious fuel like a dehydrated camel.
Why? Well it's quite straightforward: if you want the horses you must feed them. You simply don't get big power and big torque for nothing; you need the fuel burn in order to achieve the desired outputs. Sure, modern lean-burn direct injection coupled with high compression ratios do make for an improvement in economy but the results aren't as far apart as the press material may suggest. You'll be quite surprised to see how close a turbocharged engine will come to the comparable naturally aspirated engine in terms of fuel consumption when the dogs of war are unleashed.
Alright we say, so turbo'd engines still have the upperhand on their NA counterparts; they make more torque lower down, have better low speed economy & emissions and make as much power at the top end. Clearly, it's advantage turbocharging and so what's all the fuss about?
The fuss is about Throttle Response. The one thing that a turbo'd engine will never match (oh, they might come close) is the outright throttle response of a naturally aspirated petrol engine that receives an exact, and more importantly, instant dose of precisely the right amount of air flow relative to the throttle position. It's this immediacy that is ultimately missing in turbocharged engines as a result of the air having regulated passage through what is essentially an air pump. So the sensation is this: the throttle response is softer - hence the term - and from throttle off to throttle on there is a delay as the inlet air flow takes its cue from the flow of the exhaust gases.
Ok, so why is throttle response so important? It's all about maximising the control a driver has over the engine - and hence entire car - with the accelerator pedal. A little bit of throttle on gives you one reaction, a little bit of throttle off, another. FWD, AWD, RWD - it makes no difference - the fact is that a quicker reacting throttle gives the driver greater control over the dynamic attitude of the vehicle thus leading to a more rewarding driving experience. The driver is able to meter out exactly the right amount of throttle vs. steering input (remember that the two are connected by an invisible piece of string - what you do with the one affects, and is affected by, the other) and there is no better illustration of this put into practice than this epic video by our member, AdvEvo:
What he's gone and done - intentionally or unwittingly - for the viewers is a fabulous thing in this video of that paragon of throttle response: the M3 CSL. By mounting the camera in this position one can see the extent of the steering angle on the front wheels whilst also being able to hear how much throttle input is being made. Look at the steering angle, listen to the frequency and the accuracy of the throttle inputs and hopefully you'll have a much finer appreciation of the importance of throttle response.
Sure, turbocharging is closing the gap since the old days of the laggy, big blowers but it has some way to go still to matching the immediacy and precise control of a proper naturally aspirated engine. It is, and always will be, the most direct connection from the driver's foot to the driven wheels. It's what makes the cars in this zenith of natural aspiration, the M3, 911 GT3 RS, LF-A, 458 Italia and GTO unforgettable and irreplaceable.
Special thanks to André (AdvEvo) for his uiters heerlik YouTube channel. Miss that guy...
Human
You. The Road. Nothing else.
^
As ALWAYS not only an insightful read by our Martin but a well explained and well understood technical read.
Thanks mate!
Q: Martin do you think turbo development will close the gap completely going forward? With ever increasing emission laws + OEM's pushing the demand for better turbo's, companies i.e. Borg Warner, Garret etc. has a typical ever evolving market and demand for the newer and better.
Also, OEM's in this case BMW with the V8TT where the turbo's are placed on-top of the cylinder head for increased efficiency working with turbo manufacturers and new cylinder head and manifold designs could the 'ultimate in throttle response' be in reach of NA throttle response?
As ALWAYS not only an insightful read by our Martin but a well explained and well understood technical read.
Thanks mate!
Q: Martin do you think turbo development will close the gap completely going forward? With ever increasing emission laws + OEM's pushing the demand for better turbo's, companies i.e. Borg Warner, Garret etc. has a typical ever evolving market and demand for the newer and better.
Also, OEM's in this case BMW with the V8TT where the turbo's are placed on-top of the cylinder head for increased efficiency working with turbo manufacturers and new cylinder head and manifold designs could the 'ultimate in throttle response' be in reach of NA throttle response?
martinbo
Staff member
^ Look, I think they'll get close - I'm waiting to learn more about the MP4-12C's throttle response to see how far they've managed to get in this regard - but as far as I'm concerned the fundamentals of the air flow are too different to ever result in turbocharging matching the response of natural aspiration. As long as as air ingested by a turbocharger passes via a narrow inlet, is pressurised and forced to change direction at 90 degrees through the vanes of a compressor turbine, I can't see turbocharging matching an NA engine completely for throttle reactivity.
Sure, there are innovative technologies implemented nowadays, BMW's cross-flowed, twin-scroll, twin turbo arrangement does supposedly have terrific throttle response but even Chris Harris on the new F10M said that the throttle response wasn't that of an S85 or S65.
One has to consider that engines like the S65, S85 and LFA 1LR-GUE, have individual throttle bodies for each cylinder directly drawing air from a vast reservoir (inlet plenum) into the combustion chamber. So consider stepping on the gas pedal and all eight or ten valves opening in unison and ingesting dozens of litres of air in split seconds. There's no way one can achieve that kind of flow control in a turbo engine. IMO of course...
Sure, there are innovative technologies implemented nowadays, BMW's cross-flowed, twin-scroll, twin turbo arrangement does supposedly have terrific throttle response but even Chris Harris on the new F10M said that the throttle response wasn't that of an S85 or S65.
One has to consider that engines like the S65, S85 and LFA 1LR-GUE, have individual throttle bodies for each cylinder directly drawing air from a vast reservoir (inlet plenum) into the combustion chamber. So consider stepping on the gas pedal and all eight or ten valves opening in unison and ingesting dozens of litres of air in split seconds. There's no way one can achieve that kind of flow control in a turbo engine. IMO of course...
Indeed, the mechanical and technical will not be 100% sufficient enough to overcome the physics involved in airflow - logic actually (as you explained it)
Beemer B773ER
Tire Trailblazer
Great explanation Martin! Hugely insightful. 
Here's a hypothetical. Is there any way to make an engine that brings together both NA and FI benefits. Let me try and explain.
What if an engine was able to 'shut off' its forced-induction capability either by the driver's choice, or by programming the turbo component to begin working beyond a certain speed or steering angle.
Thereby, when it comes to performance driving, the NA benefit of instant throttle response remains for...say speeds under 120km/h (or if the steering angle goes beyond a certain degree), so the driver can maintain maximum control through cornering as shown in that AdvEvo M3 CSL video...but once the car is back pointing straight ahead and traveling at a fast speed the turbo's kick-in to provide an extra boost.
Or in a different scenario... the driver of a 2018 M5 is dropping his kids off to school since it's his day off. On the way to school with the little ones in the back seat he naturally has the car in its most tamed mode. In this mode the turbos are utilized to provide better fuel efficiency and improved low-end acceleration for weaving through morning traffic. Once the kids are at school, he decides to have a bit of fun and shifts the car into M-mode, thereby deactivating the turbo's and allowing him to exploit the full benefits of a naturally aspirated M5!
Does that even sound feasible in any way? Of course the engine architecture would have to be modified to incorporate this 'hybrid' (I didn't want to use that word, but no choice) engine, but if BMW can 'slap-on' turbos to NA engines that were developed before they even contemplated turbo's (eg: N52 -> N54/5), then it can't be that hard.. right?
It might not be an optimal NA engine, and neither an optimal FI engine either, and the added weight of the turbo architecture when not being utilized might be a little issue, but surely if Throttle Response is such a heavenly delight of NA engines this could be made to work.
??
Here's a hypothetical. Is there any way to make an engine that brings together both NA and FI benefits. Let me try and explain.
What if an engine was able to 'shut off' its forced-induction capability either by the driver's choice, or by programming the turbo component to begin working beyond a certain speed or steering angle.
Thereby, when it comes to performance driving, the NA benefit of instant throttle response remains for...say speeds under 120km/h (or if the steering angle goes beyond a certain degree), so the driver can maintain maximum control through cornering as shown in that AdvEvo M3 CSL video...but once the car is back pointing straight ahead and traveling at a fast speed the turbo's kick-in to provide an extra boost.
Or in a different scenario... the driver of a 2018 M5 is dropping his kids off to school since it's his day off. On the way to school with the little ones in the back seat he naturally has the car in its most tamed mode. In this mode the turbos are utilized to provide better fuel efficiency and improved low-end acceleration for weaving through morning traffic. Once the kids are at school, he decides to have a bit of fun and shifts the car into M-mode, thereby deactivating the turbo's and allowing him to exploit the full benefits of a naturally aspirated M5!
Does that even sound feasible in any way? Of course the engine architecture would have to be modified to incorporate this 'hybrid' (I didn't want to use that word, but no choice) engine, but if BMW can 'slap-on' turbos to NA engines that were developed before they even contemplated turbo's (eg: N52 -> N54/5), then it can't be that hard.. right?
It might not be an optimal NA engine, and neither an optimal FI engine either, and the added weight of the turbo architecture when not being utilized might be a little issue, but surely if Throttle Response is such a heavenly delight of NA engines this could be made to work.
??
Michael
Torque Titan
Great explanation Martin! Hugely insightful.
Here's a hypothetical. Is there any way to make an engine that brings together both NA and FI benefits. Let me try and explain.
I think porsche did this with the 911 turbo as of late. I am not sure, though.
What I am sure of is what Maritn said, minus a few technicalities here and there. My understanding is that NA will always have the best throttle response. This was the mega issue between me and my Audi friends back in the day arguing about forced induction vs. NA. The theory, then, was that NA was better because power delivery was always there with respect to throttle response. In addition, I remember reading about the degradation of turbocharged engines when compared to NA. Is this true or is it the opposite? It is one or the other if memory serves well.
I used to think that the M division would never ever in their life transition to forced induction engines. If M changes their belief, it must be because they have found a way to get those NA characteristics in an engined that is turbo charged.
One thing that I would like to sak Martin is this: what about supercharged engines? When it comes to supercharging, I never fully understood the fuss and the deal. MB has done it, but I think BMW nor Audi has ventured into that realm, at least not in significant ways.
Sunny
Premium
Great explanation Martin! Hugely insightful.
Here's a hypothetical. Is there any way to make an engine that brings together both NA and FI benefits
Yes, high revving NA engine coupled to KERS.
.Unfortunately not Michael. There is a video with Walter Rohrl himself saying how the 997 turbo turbo throttle response is not anywhere near a GT3.
Supercharging avoids turbo lag, but throttle response is still not going to be linear like NA. Audi has a supercharged engine it uses in S4, A6 etc. Biggest problem with supercharging is it is inherently inefficient cause you are wasting engine power to drive compressors. I remember reading somewhere at full power SLR engine wastes as much as 200HP to drive the compressors.
south
Vorsprung Visionary
Current Audi S4 has a supercharged V6.
So true.Yes, high revving NA engine coupled to KERS.
Best regards,
south
Michael
Torque Titan
Yes, this is true. Overlooked that.
Beemer B773ER
Tire Trailblazer
Smart ass!!
But I guess you're on to something there Sunny Jim.
How about a high-revving NA coupled with a battery/electric motor? Talk about instant response, there's your answer!
I think.....
scorpionkit76
On the Road
Hybrid turbocharger
i think the best answer would be a electrically driven forced induction...
i belive there are some research on this...
i found this in wikipedia..
A hybrid turbocharger is an electric turbocharger consisting of an ultra high speed turbine-generator and an ultra high speed electric air compressor. The turbine and compressor are high-speed aeromachines, as in a conventional turbocharger. The electrical motors run at speeds in excess of 120,000 rpm and when used as generators, generate electricity at 98.5% electrical efficiency. High electrical efficiency is paramount, because there is no mechanical link between the turbine and compressor. In other words, hybrid turbocharger refers to a series hybrid setup, in which compressor speed and power are independent from turbine speed and power. This design flexibility leads to further improvements in turbine and compressor efficiency, beyond a conventional turbocharger.
The designers claim that hybrid turbocharger technology (HTT) virtually eliminates turbo lag and enables engine downsizing without compromising engine performance. This means that a HTT equipped engine can save up to 30% on CO2 emissions and fuel economy compared to an equivalent naturally aspirated engine.
HTT has currently been developed and tested to proof of concept stage by UK based company, Aeristech Ltd who also hold the patents for the design.
and here is the rest
Hybrid turbocharger - Wikipedia, the free encyclopedia
i think the best answer would be a electrically driven forced induction...
i belive there are some research on this...
i found this in wikipedia..
A hybrid turbocharger is an electric turbocharger consisting of an ultra high speed turbine-generator and an ultra high speed electric air compressor. The turbine and compressor are high-speed aeromachines, as in a conventional turbocharger. The electrical motors run at speeds in excess of 120,000 rpm and when used as generators, generate electricity at 98.5% electrical efficiency. High electrical efficiency is paramount, because there is no mechanical link between the turbine and compressor. In other words, hybrid turbocharger refers to a series hybrid setup, in which compressor speed and power are independent from turbine speed and power. This design flexibility leads to further improvements in turbine and compressor efficiency, beyond a conventional turbocharger.
The designers claim that hybrid turbocharger technology (HTT) virtually eliminates turbo lag and enables engine downsizing without compromising engine performance. This means that a HTT equipped engine can save up to 30% on CO2 emissions and fuel economy compared to an equivalent naturally aspirated engine.
HTT has currently been developed and tested to proof of concept stage by UK based company, Aeristech Ltd who also hold the patents for the design.
and here is the rest
Hybrid turbocharger - Wikipedia, the free encyclopedia
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BMW M
BMW M GmbH, formerly known as BMW Motorsport GmbH, is a subsidiary of
BMW AG that manufactures high-performance luxury cars. BMW M ("M" for "motorsport")
was initially created to facilitate BMW's racing program, which was very successful
in the 1960s and 1970s. As time passed, BMW M began to supplement BMW's vehicle
portfolio with specially modified higher trim models, for which they are now most
known by the general public. These M-badged cars traditionally include modified engines,
transmissions, suspensions, interior trims, aerodynamics, and exterior modifications
to set them apart from their counterparts. All M models are tested and tuned at BMW's
private facility at the Nürburgring racing circuit in Germany.
Official website: BMW M
Official website: BMW M
