People who seem to be happy with the new F80 M3 / F82 M4 engine direction

[swamp2]

Originally Posted by Levi

LOL at the N54 fans. The engine is not a marvel of engineering calimed by fans. Toyota had such an engine even more advanced two decades ago. Nissan had turbocharged I6 engines long before BMW making alot more power from even smaller displacement with even higher redline.


An the N54 was never really that new, just a turbocharged M54.

Yes.

Originally Posted by Levi

By the way, contrary to what most think, S65 is more old, it is based on S60 that powered the M3 GTR. S65 is a pure Motorport engine, an engine that was developed by BMW Motorsport for racing only. Based on it was built the S65 for road. And based on S65 was derived, contrary to what most think eventhough it came before, the S85, an S65 with two more cylinders.

I was under the impression that (and have been critical of it for that reason) the S65 is more or less identical to the S85 qwith two cylinders removed. Are you saying the S85 was derived from the S60 with two ADDITIONAL cylinders? There is no denying the similarities between the S85 and S65.

[NISFAN]

Originally Posted by swamp2

Fans, quite obviously, not fanboys. The S54 is a fine engine but has a sustantially less desireable (i.e. peaky) torque curve. I guess great for folks like yourself who like small engines, big turbos and lots of turbo lag...

Lol, as you keep banging on, horsepower is the true measure of engine capability ......said tongue in cheek, of course, torque delivery is an important factor, but the engine we are talking about is smaller than an s65. Bigger displacement allows you to be more tactical about torque delivery throughout the rev range.

Originally Posted by swamp2

Terrible, apples to oranges comparison. How about M3 GTS vs. CSL. Not much of an engine competition at all.

Well that hasn't gone well for you, the M3 GTS is 450hp from 4.4 litres or an even lower 102hp/litre. The CSL version s54 has minor upgrades (induction system, exhaust manifold, cam profiles), same internals. ......a lightly breathed on engine like the CSL itself.

[mkoesel]

Originally Posted by NISFAN

No, but the point is this....any car needs a minimum amount of torque to make it driveable. The bigger the engine, the easier it is to achieve the minimum torque, and therefore more attention can be directed at getting maximum torque higher up in the rev range. If that makes sense.

Well, I am going to refrain from entering a debate about this hypothesis. But remember, due to gearing, torque seen at the wheels is many times what the engine itself produces.

[mkoesel]

Originally Posted by swamp2

I was under the impression that (and have been critical of it for that reason) the S65 is more or less identical to the S85 qwith two cylinders removed. Are you saying the S85 was derived from the S60 with two ADDITIONAL cylinders? There is no denying the similarities between the S85 and S65.

I think he is suggesting that the S65/S85 common architecture was evolved from the P60 racing engine. I believe the bore and stroke are different - P60 having 94mm bore like an S62, but destroked dramatically to 4L. P60 may have a shorter deck than the S65/S85 too - it certainly looks compact, though that could be due to heads too since I am not sure if they have dual VANOS. Of course, all BMW V8s have the same 98mm bore spacing so in some sense all these engines evolve from the M60. I'm sure there are plenty of similarities in the rest of the engine too - valvetrain, induction, lubricatin, cooling, etc. Obviously lessons learned from one short stroke V8 will be applied to another, but saying that the latter is based on the former is probably a stretch.

BTW, there was no S60 to my knowledge - the few road going cars homolongated to use this engine just used a detuned P60, as far as I know.

[BMW269]

Originally Posted by mkoesel

I think he is suggesting that the S65/S85 common architecture was evolved from the P60 racing engine. I believe the bore and stroke are different - P60 having 94mm bore like an S62, but destroked dramatically to 4L. P60 may have a shorter deck than the S65/S85 too - it certainly looks compact, though that could be due to heads too since I am not sure if they have dual VANOS. Of course, all BMW V8s have the same 98mm bore spacing so in some sense all these engines evolve from the M60. I'm sure there are plenty of similarities in the rest of the engine too - valvetrain, induction, lubricatin, cooling, etc. Obviously lessons learned from one short stroke V8 will be applied to another, but saying that the latter is based on the former is probably a stretch.

BTW, there was no S60 to my knowledge - the few road going cars homolongated to use this engine just used a detuned P60, as far as I know.

Yes it was a typo. I meant P60B40. I don't know what parts are common between P60B40 and S65B40. I guess none, but S65 is related to P60.

[Boss330]

Originally Posted by swamp2

I disagree. With significant changes to redline, intake system, exhaust system and block one can radically alter the sound of any engine. Yes there is still something essential the crank type and firing order contribute, but it is NOT the single factor.

I really expected a better reply. You're obviously astute on engines in general. However, it seems you want to rest your argument solely on crankshaft configuration. I don't disagree that is important but it is only roughly as important as power delivery - i.e. torque/power curve shapes and redline.

All of my previous replies was posted on an iPhone, not the best tool to type long replies on

Obviously revs and exhaust change the pitch of the exhaust. But let's say that you put the M3 intake and exhaust on a Mustang V8 and rev it over the same rev range as the S65. You would not be able to tell any difference in sound. Try to put the same exhaust on a 458 Italia (intake is allready similar). VERY different sound! What's the main difference? (hint: Crankshaft layout )

Originally Posted by swamp2

A bedplate design is significantly more stiff than a traditional design. Although overall noise is dominated by intake and exhaust noise there is also a significant content to overall sound level and sound quality directly from the engine block and engine itself. The stiffness of the block greatly affects this component of the sound.

It's fine for you to state this but you've not provided any evidence. My evidence was (again):

• Bedplate design (a major design decision by the way)
• Individual throttle bodies
• Highly efficient/engineered heads leading to very high flow at high rpm and providing
• High rpm linear power delivery (shape of torque and power curves)

Even though the S65 might have a bedplate bottom end, the Modular Ford has a similarly stronger bottom end block design unlike traditional small block V8's:



The differences in block strength here are highly unlikely to be detectable on the soundtrack IMHO.

Individual throttle bodies do make a difference, but is really not part of the engines basic design. Just like exhaust, it's added on parts to enhance the efficiency of the basic engine design. Individual throttle bodies are mainly there to get super sharp throttle response. Regardless, a Boss Mustang Laguna Seca (or any other Mustang V8) would sound even more similar to the S65 (as regards intake sound), still won't sound like a 458 Italia.

The S65 isn't the only engine that has high flowing heads...

The result is an intake port that outflows the Ford GT intake port by 4 percent and the Yates D3 (NASCAR) intake port.

The Boss 302 receives CNC ported heads cast in 356 aluminum providing additional airflow and strength, and a higher lift exhaust camshaft profile is used. Valvetrain components were lightened as much as possible, including the use of sodium filled exhaust valves, while strengthened powdered metal rods and forged aluminum pistons were added. Piston-cooling jets were also deleted, which are standard in the 5.0 model. Exterior changes include a high-mount intake plenum (as opposed to the standard engine's low-mounted one) with shorter runners to improve high-rpm power. Power is increased from 412 hp (307 kW) to 444 hp (331 kW), and torque drops from 390 lb·ft (530 N·m) to 380 lb·ft (520 N·m) due to the upgrades. The Boss's redline is increased to 7500 rpm, but has been verified stable up to 8400.

And this is only from a cheap main stream Ford, not even an exotic manufacturer...

The Boss 302 Power curve isn't all that bad either:



And, the Maserati Granturismo Sport has a engine that isn't half bad either. It's not like the S65 is something so special that BMW must have discovered some secret ingredient no one knows about...

Originally Posted by swamp2

Furthermore the bold part above about ability to make power at high revs is simply completely false. The S65 and F430 have very similar power curves at the upper rpms (nearly linear). However, I've not been able to locate a proper factory dyno for the F430. From some of the regular old "garage" dynos the S65's ability to maintain flat torque and linear power right up to redline appears to be even superior to the F430!

Not true. Heads, valve system and the entire intake system are as highly engineered for flow across a extremely wide rpm range as many other parts of an engine. Which leads me to your next statement. Please find a V8 (or any production) car engine with as broad and flat of a torque curve as the S65. it has 90% of peak torque from 2500 rpm to 8200 rpm (98% of redline). The thing is - you can't! Also, you are now even talking aftermarket compared to stock with is really grasping at straws...

Factory BMW S65 M3 Dyno

Again, my argument isn't that the S65 is a bad engine. It's definitely a highly tuned V8, just like so many other V8's. Some from the factory, some with aftermarket parts. But, those V8's share the same basic architecture of a cross plane crank, 90 deg V, multi valve cylinder heads and DOHC. Where the Ferrari engines differ from this concept is in their crankshaft layout. All else is the same (or you might care to elaborate on vital architectural differences here?).

No matter how you try to argue about how much the heads flow, bedplate engine block etc. The factor that makes a Ferrari V8's sound stand out from other V8's is down to the fact that it uses a flat plane crank!

One other issue is the huge weight saving on a flat plane crank, making the throttle response much better.

I suggest you read these articles/threads to learn a bit more about why there IS a big difference between cross plane and flat plane crank designs:

http://www.m3post.com/forums/showthread.php?t=283826

http://www.autozine.org/technical_sc...ne/smooth4.htm

http://www.ferrari.com/English/GT_Sp...raftshaft.aspx

And some videos of a Chevy with flat plane crank, notice how different it sounds...

And notice how the M3 GTR sounds so different from the std M3 (with the P65 engine which actually is a S65 engine, but only with a, YES, flat plane crankshaft).

http://www.youtube.com/watch?feature...&v=LeiA9vyi7YM


I'll finish off by quoting Ferrari:

Whether a flat or cross-plane crankshaft is chosen depends on what kind of performance is required. To get maximum performance from the engine, the flat-plane must be used but for all-round functioning the cross-plane is best.

The advantages of the flat-plane crankshaft over the cross-plane one can be summarised as follows:

A flat-plane crankshaft is lighter than a 90-degree, or cross-plane crankshaft, and, having a lower rotating mass than the latter, provides sharper response as well as allowing higher maximum revs, useful when seeking higher power outputs. Another advantage of the flat-plane crank is that it allows more efficient exhaust manifold design.

[AlteredBe4st]

I currently Own the E9X but I am looking forward to the inline 6 twin turbo F8X M3/m4. Having driven other turbo vehicles and seeing the increase of Gains in hp and torque after modding a turbo vehicle vs NA I am curious to see what the next gen will bring to the table. I most likely will keep my E9X and Possibly ge an M4 down the road after the second year production.

[swamp2]

Originally Posted by Boss330

All of my previous replies was posted on an iPhone, not the best tool to type long replies on

Fair enough!

I'm well aware of both engine balance, crank design options, rotational inertia, firing order and the like. Again, I freely admit that cross vs. flat plane is a major engine architectural feature, however, again, it is only one component that defines an engines entire character. In my opinion both redline and power delivery as just as important in defining character. Let's think of it this way. Imagine some (odd) hypothetical flat plane V8 engine with every aspect both low performance and even low quality (carburetors, distributor, cast iron everything, no forged parts, no advanced electronics, loose tolerances, heavy, over-designed parts, no variable valve system, no advanced knock detection, etc.). Now compare that engine and an S65 to the F430. Yes somewhat of an extreme example but you should get the point. I believe you are losing sight of the forest for the trees.

Let's talk a bit more about a bedplate design and your component view vs. my system level view. Here is one decent reference for you - engine builder magazine link.

The BLS engine is not a bedplate design and does not need to be whereas there are fundamental engineering reasons (mostly redline and high peak combustion pressures) why both the F430 and S56 engines are bedplate designs. You can start with any part of the engine (say crank) and work your way out and say that everything else is just an accessory, just a head, just a throttle body, just the cams, just the ECU, etc. However, the fact of the matter is that an engine; sound, performance, efficiency, character, power delivery, longevity, etc. are all due to the sum of the parts comprising the engine system. To minimize the importance of some components also minimizes the key performance benefits those components provide. These "components" certainly are not designed in isolation and certainly can't be picked off of parts bin shelf willy-nilly and successfully integrated into a given engine design. Although neither of us has (nor can get) enough access to design details for the BLS (what is its darn engine code anyway...) nor S65 engines, I would be wiling to guarantee that following both air and fuel from intake and gas tank to the combustion chamber would yield a significant number and of quantitative and qualitative differences. Other differences would be beyond the realm of inspection and would require great engineering insight from OEM. Other engine components and systems would yield a similar array of differences. Because of the overall engineering challenges in getting high specific output and high redlines I contend there will be plenty more similarities among the S65 and F430 than S65 and BLS.

Your comparison between the BLS heads and the M3 heads also falls flat. No BMW isn't the only company with "high flowing" heads. But also the days of hot rodders placing a head on a "flow bench" are long since gone (at least for high end race and high end consumer engines). That work today, as well as modeling the entire intake tract and the actual combustion process is now done on supercomputers using computational fluid dynamics (again it is at least done this way for many high rpm racing engines and some production engines). The torque curves for the S65 vs. the BLS engine in part, demonstrate this system level engineering excellence by BMW M. The BLS engine has a pretty strong drop off in torque beginning as low as 5300 rpm. This not an insignificant detail. You can really FEEL this and it absolutely is detrimental to performance. Again it is a very fine engine, they just did not need the engineering and expense to make it breathe at 8000+ rpm to achieve their design goals, a larger displacement engine with more torque provides that. Just as Ferrari and BMW (S65) went a different direction for a different goal. All of these engines perform admirably they just go about it in a different fashion, and again the resulting CHARACTER of the S65 and F430 are much more similar than those of the S65 and BLS engine.

I think your videos (and now "mine") make my point more than yours. Neither the M3 GTR nor the other videos sounds ANYTHING like a Ferrari to me. In fact, I bet most people, general enthusiasts included, could not identify a flat plane vs. cross plane V8 if somehow that was the only single change to an engine. We don't have the luxury of making such comparisons because flat plane tends to be accompanied by a wide variety of other components and systems that all work together to produce high redlines and flat torque curves.

I'll end with a couple of videos myself that show how radically different exhausts can make the S65 sound. In my evaluation these sound much more like a F430 than either of the flat plane videos you posted. Less so at idle but then again at idle you have much more relative engine noise than intake or exhaust noise

I contend you simply cannot make a BLS Mustang sound like this. Why - primarily redline. Higher redline have just about everything on the engine moving at higher speeds, rotational and linear and this vast array of excitations are what produce the higher frequencies in the sound spectrum.

I think we'll probably have to agree to disagree here. To you crankshaft type is the single most important factor in judging two engines similarity or dissimilarity, whereas to me, both redline and power delivery are either equally or more important. Good discussion! Cheers.

[Boss330]

Originally Posted by swamp2

Fair enough!

I'm well aware of both engine balance, crank design options, rotational inertia, firing order and the like. Again, I freely admit that cross vs. flat plane is a major engine architectural feature, however, again, it is only one component that defines an engines entire character. In my opinion both redline and power delivery as just as important in defining character. Let's think of it this way. Imagine some (odd) hypothetical flat plane V8 engine with every aspect both low performance and even low quality (carburetors, distributor, cast iron everything, no forged parts, no advanced electronics, loose tolerances, heavy, over-designed parts, no variable valve system, no advanced knock detection, etc.). Now compare that engine and an S65 to the F430. Yes somewhat of an extreme example but you should get the point. I believe you are losing sight of the forest for the trees.

Let's talk a bit more about a bedplate design and your component view vs. my system level view. Here is one decent reference for you - engine builder magazine link.

The BLS engine is not a bedplate design and does not need to be whereas there are fundamental engineering reasons (mostly redline and high peak combustion pressures) why both the F430 and S56 engines are bedplate designs. You can start with any part of the engine (say crank) and work your way out and say that everything else is just an accessory, just a head, just a throttle body, just the cams, just the ECU, etc. However, the fact of the matter is that an engine; sound, performance, efficiency, character, power delivery, longevity, etc. are all due to the sum of the parts comprising the engine system. To minimize the importance of some components also minimizes the key performance benefits those components provide. These "components" certainly are not designed in isolation and certainly can't be picked off of parts bin shelf willy-nilly and successfully integrated into a given engine design. Although neither of us has (nor can get) enough access to design details for the BLS (what is its darn engine code anyway...) nor S65 engines, I would be wiling to guarantee that following both air and fuel from intake and gas tank to the combustion chamber would yield a significant number and of quantitative and qualitative differences. Other differences would be beyond the realm of inspection and would require great engineering insight from OEM. Other engine components and systems would yield a similar array of differences. Because of the overall engineering challenges in getting high specific output and high redlines I contend there will be plenty more similarities among the S65 and F430 than S65 and BLS.

Your comparison between the BLS heads and the M3 heads also falls flat. No BMW isn't the only company with "high flowing" heads. But also the days of hot rodders placing a head on a "flow bench" are long since gone (at least for high end race and high end consumer engines). That work today, as well as modeling the entire intake tract and the actual combustion process is now done on supercomputers using computational fluid dynamics (again it is at least done this way for many high rpm racing engines and some production engines). The torque curves for the S65 vs. the BLS engine in part, demonstrate this system level engineering excellence by BMW M. The BLS engine has a pretty strong drop off in torque beginning as low as 5300 rpm. This not an insignificant detail. You can really FEEL this and it absolutely is detrimental to performance. Again it is a very fine engine, they just did not need the engineering and expense to make it breathe at 8000+ rpm to achieve their design goals, a larger displacement engine with more torque provides that. Just as Ferrari and BMW (S65) went a different direction for a different goal. All of these engines perform admirably they just go about it in a different fashion, and again the resulting CHARACTER of the S65 and F430 are much more similar than those of the S65 and BLS engine.

I think your videos (and now "mine") make my point more than yours. Neither the M3 GTR nor the other videos sounds ANYTHING like a Ferrari to me. In fact, I bet most people, general enthusiasts included, could not identify a flat plane vs. cross plane V8 if somehow that was the only single change to an engine. We don't have the luxury of making such comparisons because flat plane tends to be accompanied by a wide variety of other components and systems that all work together to produce high redlines and flat torque curves.

I'll end with a couple of videos myself that show how radically different exhausts can make the S65 sound. In my evaluation these sound much more like a F430 than either of the flat plane videos you posted. Less so at idle but then again at idle you have much more relative engine noise than intake or exhaust noise

I contend you simply cannot make a BLS Mustang sound like this. Why - primarily redline. Higher redline have just about everything on the engine moving at higher speeds, rotational and linear and this vast array of excitations are what produce the higher frequencies in the sound spectrum.

I think we'll probably have to agree to disagree here. To you crankshaft type is the single most important factor in judging two engines similarity or dissimilarity, whereas to me, both redline and power delivery are either equally or more important. Good discussion! Cheers.

Obviously I agree that redline, CR, exhaust, intake CONTRIBUTES to sound. To say anything else would be foolish (And those M3's you posted sounded really good).

But, in engineering terms there are really two different V8 concepts: Either with a cross plane crank or a flat plane crank. Within those two concepts you can obviously go to extremes and have multiple variations on the theme. So, in the area of "state of tune" the S65 is obviously closer to a Ferrari V8 than it is to a Chevy V8 in a Suburban. But so is the BLS engine (although not as close as the S65). And with tuning the BLS engine can come even closer to the S65. That is just down to "tuning". So yes, in terms of exploiting the potential of maximum output the S65 is closer to a Ferrari engine.

But that just reinforces my point. If we concede that the S65 is in just as high a state of tune as a Ferrari V8 and with similarly highly developed hardware. Then what is the only difference between them? The crankshaft!!! That is what, according to engineers, Ferrari and everyone else, is the deciding factor when deciding what kind of engine you need. If you want a comfortable, vibration free etc. engine: Go cross plane. If you want to build a high performance engine AND be willing to trade off NVH issues: Go flat plane.

To put it simply: The Ferrari/Maserati V8 engines are probably the best example between the two concepts. The Ferrari uses a flat plane crank Maserati a cross plane crank. Apart from that the engines are similar.

http://en.wikipedia.org/wiki/Ferrari/Maserati_engine

The S65 is comparable to the Maserati engine, since it has a cross plane crank. The P65 to the Ferrari since it has a flat plane crank. That crank design makes for a different sound and better exhaust scavenging.

To my ears the sound is different, the flat plane crank engine doesn't have that cross plane "burble" at idle and medium revs. Under acceleration there is also a different sound.

[mkoesel]

The flat plane crank gives the Ferrari engines a unique sound vs a cross plane V8, but clearly the engineering challenges become more significant as RPM increases regardless of crank design. So in that regard the S65 is more like a Ferrari engine than it is like other typical V8 engines out there. And that includes those from many other manufacturers from Toyota to Hyundai to Mercedes to FoMoCo. Of course, piston speed is one of the bigger concerns and that is a function not just of RPM but of stroke too.

We would be remiss to not point out, incidentally, that Ferrari and Porsche have moved on from the 8K RPM club to the 9K RPM club now. So they are playing in a different league. And 125hp/L too. In fact I've read that the new 458 Scuderia is going to hit 600hp from the 4.5L engine which is 133hp/L. Maybe we'll see 10000 RPM and 150hp/L before naturally aspirated engines finally fade away once and for all.

[BMW269]

Originally Posted by mkoesel

We would be remiss to not point out, incidentally, that Ferrari and Porsche have moved on from the 8K RPM club to the 9K RPM club now. So they are playing in a different league. And 125hp/L too. In fact I've read that the new 458 Scuderia is going to hit 600hp from the 4.5L engine which is 133hp/L. Maybe we'll see 10000 RPM and 150hp/L before naturally aspirated engines finally fade away once and for all.

When will NA engines fade away we do not know, but there are no many left, and in the next years I can only count a few. I am not sure, but it seems very likely Ferrari, Lamborghini and Aston Martin (unless they get AMG engine) will keep their NA V12 engines, at least for the next generation, but then we do not know, Pagani went FI V12. It is sure the 911 GT3 will keep its NA 3.8 Flat 6, as for the rest, Porsche is about to restructure its sportscars line-up by squeezing the 981 and the 991 between the 550 and the 959. What is certain is that the NA 3.4l Flat 6 will be replaced by a more powerfull FI 2.4l Flat 4. The Gallardo/R8 is a tough decision. It is yet unknown if it will get a FI V8 or a NA V10. Finally the last car is the 458 Italia. It is unknown what engine it will get, a "new" NA V8 or a revised FI V8, though their are (wrong?) rumors of FI V6. We shall be able to guess once we know what engine the California replacement will get. Will it get the new FI 3.8l V8 or will it get - like the current got the NA 4.3l V8 from the F430 - the NA 4.5l V8 from the 458 in detuned form?

To summarise, the last NA engines will be the Porsche Flat 6, Ferrari V8 and probably the V12 engines. I forgot the Honda NSX II.

The future of NA engines dépends on two things: hybridisation, yet it means nothing, there are many hydrid cars with FI (e.i. McLaren P1, BMW i8), but it also dépends on racing régulations. Now F1 went FI, but if FI will also have advantages in GT, then it might very well be the end of NA engines.

[mkoesel]

Don't forget about the good old American V8, Levi. As long as they keep putting them in trucks, they'll still be there to power muscle cars and sports cars too. Also, Japanese companies have been largely resistant to FI trends as well, especially for higher displacement engines.

[Tåst]

Now many manufacturer just pull turbo´s every engine, principle "if customers buy still, we save money", they just try to avoid Eu emission penalty payments.

[swamp2]

Originally Posted by NISFAN

Lol, as you keep banging on, horsepower is the true measure of engine capability ......said tongue in cheek, of course, torque delivery is an important factor, but the engine we are talking about is smaller than an s65. Bigger displacement allows you to be more tactical about torque delivery throughout the rev range.

Yes when it comes to absolute performance capability, hp (to weight ratio) is the key metric that tells one more about the performance than any other metric. And in the exact same breath the engines torque curve (equivalently power curve but easier to see in the torque curve) is a key measure of an engines character. I don't buy the larger displacement article. Large displacement engines without advanced electronics, advanced variable valve systems and an advanced head and intake tract can not maintain torque at high rpms. Sure more displacement = more torque but that isn't what you've claimed.

Originally Posted by NISFAN

Well that hasn't gone well for you, the M3 GTS is 450hp from 4.4 litres or an even lower 102hp/litre. The CSL version s54 has minor upgrades (induction system, exhaust manifold, cam profiles), same internals. ......a lightly breathed on engine like the CSL itself.

If you want to obsess in specific output sure, however, I argue a more holistic approach to an engines character and superiority. Even just on the electronic side the ECU in the S65 is capable of 200 million calculations per second, that in the S54 - about 25 million. That combined with the advanced ion knock detection built into the ignition coils in the S65 take its electronics so far past the S54 and make it look a bit primitive. Also a bedplate block as mentioned in the prior discussions, made from the same aluminum alloy in the sam facility as that which makes their F1 blocks. What's in the old S54 - a good old fashioned cast iron block... The same comments about torque curve as the vs. Boss 302 Laguna Seca apply to the S54 (not nearly as broad nor flat).

[swamp2]

Originally Posted by mkoesel

The flat plane crank contributes to the Ferrari engines unique sound vs a cross plane V8...

I've corrected your statement...

[swamp2]

Originally Posted by Boss330

But, in engineering terms there are really two different V8 concepts: Either with a cross plane crank or a flat plane crank. Within those two concepts you can obviously go to extremes and have multiple variations on the theme. So, in the area of "state of tune" the S65 is obviously closer to a Ferrari V8 than it is to a Chevy V8 in a Suburban. But so is the BLS engine (although not as close as the S65). And with tuning the BLS engine can come even closer to the S65. That is just down to "tuning". So yes, in terms of exploiting the potential of maximum output the S65 is closer to a Ferrari engine.

I also disagree with this. Yes the crankshaft is at the heart of any engine and does represent a major design decision. However, the sum of the other design decisions contribute more to engine character. To me tuning means software or simple bolt ons and again those are not what distinguish a BLS V8 from the S65.

Originally Posted by Boss330

But that just reinforces my point. If we concede that the S65 is in just as high a state of tune as a Ferrari V8 and with similarly highly developed hardware. Then what is the only difference between them? The crankshaft!!! That is what, according to engineers, Ferrari and everyone else, is the deciding factor when deciding what kind of engine you need. If you want a comfortable, vibration free etc. engine: Go cross plane. If you want to build a high performance engine AND be willing to trade off NVH issues: Go flat plane.

Agree.

Originally Posted by Boss330

The S65 is comparable to the Maserati engine, since it has a cross plane crank. The P65 to the Ferrari since it has a flat plane crank. That crank design makes for a different sound and better exhaust scavenging.

The M145A in the MGTS does appear to be a good comparison to the S65, although down quite a bit on redline and specific output, it's power character matches the S65 fairly well and exhibits a better ability to rev and breathe (i.e. maintain torque at higher rpms) as compared to the BLS. Again, as mentioned above the Audi RS4 V8 is another good comparison.

Originally Posted by Boss330

To my ears the sound is different, the flat plane crank engine doesn't have that cross plane "burble" at idle and medium revs. Under acceleration there is also a different sound.

There is no matching or replacing the very unique sound of a flat plane Ferrari V8. However, again, the videos I posted sound a heck of a lot closer to them then the BLS video you posted

Again good discussion, cheers.

[Boss330]

I completely agree that the S65 sounds much closer to the Ferrari flat plane crank engine, which is down to rpm in particular.

I think we just emphasise different traits to the engine design. For me, there is two separate V8 designs: Cross plane and flat plane. The rest is, for me, just variations on a theme depending on what use the engine is intended for (i.e DOHC, cam in block, 4 valve/2 valve etc.). You can change that hardware on both designs and it will obviously change the engines characteristics, but no matter what you change of other hardware, a cross plane crank and flat plane crank engine will still be very different. You can tune a cross plane V8 to the same specific output, but the flat plane engine will still have superior response and exhaust scavenging. Leaving room for more power and a sharper response. There IS a reason F1 V8 engines, and the P65, use a flat plane crank.

The S65 and P65 is a really good example that validates the point about the importance, and reasons, to use a flat plane crank on a engine where maximum power and response is of importance.

These two vids illustrate the difference between a cross plane and flat plane crank engine. Notice how you have two adjacent cylinders firing in sequence on the cross plane crank engine. This is what gives the V8 that uneven, burbly sound, and causes exhaust scavenging issues.

I'll finish off once again by quoting Ferrari:

Eight-cylinder engines with a 90 degree angle between their cylinder banks are a relatively recent addition to Ferrari history.
Apart from the engine sported by the 1956 World Championship-wining F1 car, which Ferrari inherited from Lancia after the latter pulled out competition, and the one mounted to the 248 sports prototype in the early 1960s, it was 1973 before a Ferrari would be powered by an engine with this specific architecture.

Characteristically flat-plane crankshaft engines have a crankshaft with crankpins angled at 180 degrees to each other or "flat" i.e. on the same plane.

Generally speaking V8 engines have a 90 degree angle between the cylinder banks with each crank pin offset at 90 degrees from the adjacent ones i.e. they are "crossed" at 90 degrees. Hence the cross-plane name. Whether a flat or cross-plane crankshaft is chosen depends on what kind of performance is required. To get maximum performance from the engine, the flat-plane must be used but for all-round functioning the cross-plane is best. This why all Ferrari V8s engines (from the 308 to the 328, the 348 to the 355,the 360 to the 430,and the special high performance GTO series, the F40 and the recent California, our first front V8) use a flat-plane crankshaft.

The advantages of the flat-plane crankshaft over the cross-plane one can be summarised as follows:

A flat-plane crankshaft is lighter than a 90-degree, or cross-plane crankshaft, and, having a lower rotating mass than the latter, provides sharper response as well as allowing higher maximum revs, useful when seeking higher power outputs. Another advantage of the flat-plane crank is that it allows more efficient exhaust manifold design.

http://www.ferrari.com/English/GT_Sp...raftshaft.aspx

[pkimM3r]

NISFAN, what is your background (car knowledge) and driver experience level?

I think you should try driving a turbocharged car and an n/a car with the same power output back to back. You will then understand the definition of turbo lag. One car will definitely not respond as well as the other when pressing the gas pedal.

[Boss330]

Originally Posted by swamp2

I've corrected your statement...

mrkoesel's statement was correct

[mkoesel]

Originally Posted by swamp2

I've corrected your statement...

Note that I wasn't trying to say it was the only thing determining the differences in engine sound.

Just like it would be correct to say that wide hips give Beyonce a different look from Kanye West. Certainly not the only thing that provide the differing aesthetic! I won't pull the thread off topic by enumerating some of the other interesting properties that also contribute.

[swamp2]

Originally Posted by Boss330

I completely agree that the S65 sounds much closer to the Ferrari flat plane crank engine, which is down to rpm in particular.

Thus in large part contradicting your earlier belief/statement that the crankshaft type was the largest determining factor in an engines acoustics.

Originally Posted by Boss330

I think we just emphasize different traits to the engine design. For me, there is two separate V8 designs: Cross plane and flat plane. The rest is, for me, just variations on a theme depending on what use the engine is intended for (i.e DOHC, cam in block, 4 valve/2 valve etc.). You can change that hardware on both designs and it will obviously change the engines characteristics, but no matter what you change of other hardware, a cross plane crank and flat plane crank engine will still be very different.

And I've already demonstrated the the sum of other design choices can easily overwhelm any effects or advantages of a flat plane design. Yes all things equal a flat plane is a better foundation for a very high performance engine. Sure it is a useful geometric/kinematic archetype classification system but beyond that I have shown its just not as important as you think.

Now all this being said I did perhaps publicly but certainly privately had hoped the S65 would be a flat plane design. The reason BMW did not was because the S65 is simply the S85 V10 from the M5 with two cylinders lopped off. However, another significant factor is engine balance. A cross plane V8 has near perfect first and second order balance whereas the flat plane V8 achieves first order but not second order balance. This makes the cross plane superior from an NVH standpoint (and as you stated somewhat inferior for an all out race/sports engine). Typically extremely high rpms are hampered in a cross plane V8 design but that obviously wasn't much of a real world limitation in the S65 (unless you call 8400 rpms somehow not high). BMW M had their cake and ate it too in this regard.

It's probably well overdue to get back to talking about forced induction...

[clar]

In my recent M event at Sepang, I spoke with one of the instructors who drove the development F80/82 almost on a daily basis. He promised me that the new power-train contains something new and innovative. That means it's not a case of a simply slapping 2 turbos on the N55 and calling it a day. He even said there is a another power rush at the higher rpm range. I was interrupted by some clowns and didn't manage to probe further. I am still hitting myself on this. I was going to ask him if it contained a 3rd turbo, an electric turbo, or something else...