Hurry up before they are gone

[GregW / Oregon]

Originally Posted by southlight

Gaggenau makes fine appliances, don't they?

Best regards, south

Yes, I've had Gaggenau ovens and range for 20+ years. Just replaced them with their latest.

[lucid]

Originally Posted by sdiver68

OK, we'll agree to disagree. There is no inherent superiority of responsiveness or smoothness to an NA engine over an FI engine. There are only the engineering trade-offs the engine designer decided to build into that engine.

Yep, we'll need to disagree on this one. As I've said before, the extra cylinders of a larger displacement NA engine provide additional power strokes per shaft rotation and even out the torque output (if you plot torque at shaft over time, you'll see this clearly) and compressors are powered by the exhaust gasses from the engine so there is a time constant there. Those are both facts, not opinions. If you were to ask, how much of a noticable difference do they make, I can maybe see what you are saying as that's opinion.

[mesier1111]

Originally Posted by ruff

Not to be overly critical, but you do know the term "whatever" is one of the rudest words in the Engish language, it is so arrogant/passive aggressive, and there is no good response to it.


Looking forward to it. We all really need to get a life.

Dude, I don't read many post from you or anyone over here and already you are getting on my nerves........

[mesier1111]

Originally Posted by ruff

How could anyone get that worked up about metal, a bag of bolts, and wheels is beyond Me. Is it the hypnotic nature of the Roundel?

If thats true, why the hell you waste so much time posting on a car forum?

[Sedan_Clan]

Originally Posted by mesier1111

If thats true, why the hell you waste so much time posting on a car forum?

+3

It's kinda like the pot calling the kettle black.

[sdiver68]

Originally Posted by lucid

Yep, we'll need to disagree on this one. As I've said before, the extra cylinders of a larger displacement NA engine provide additional power strokes per shaft rotation and even out the torque output (if you plot torque at shaft over time, you'll see this clearly) and compressors are powered by the exhaust gasses from the engine so there is a time constant there. Those are both facts, not opinions. If you were to ask, how much of a noticable difference do they make, I can maybe see what you are saying as that's opinion.

However, more cylinders and torque pulses per unit of time are NOT an indication of rear wheel "smoothness and tractability" or putting power to the ground. An example contrary to your theory would be World Superbike, where V-Twins from Ducati and Honda dominated over the inline-4's of Suzuki and Yamaha because less torque pulses per time frame actually translated at the rear wheel to easier control and the ability to put the power to the pavement quicker coming out of corners.

Another point in your analysis of smoothness as relates to M3 v 335i is that an inline engine is inherently more smooth than a Vee. Inline 6's are dynamically balanced and free from 1st and 2nd order vibrations. V's are not balanced.

Thus we'll have to agree to disagree even on which facts are more important on the overall design of an engine

[heyimsexy]

Originally Posted by Garrett

The M3 looks like a elder statesmen, while the 135tii looks like a rebellious prince!

-Garrett

HHAHAHAHHAHAHHAHAHHAHAHA that was so gay

[Davo2003]

Originally Posted by heyimsexy

HHAHAHAHHAHAHHAHAHHAHAHA that was so gay

+ infinity

[lucid]

Originally Posted by sdiver68

However, more cylinders and torque pulses per unit of time are NOT an indication of rear wheel "smoothness and tractability" or putting power to the ground. An example contrary to your theory would be World Superbike, where V-Twins from Ducati and Honda dominated over the inline-4's of Suzuki and Yamaha because less torque pulses per time frame actually translated at the rear wheel to easier control and the ability to put the power to the pavement quicker coming out of corners.

Sorry, we are talking cars not bikes. Bikes have different dynamics. Regardless, I am curious as to how you can conclude the claimed improvement in traction was caused by less torque pulses. This is counter intuitive and goes against physics unless I'm missing something in that scenario (I don't race motorcycles, but raced bicycles for many years). When you are cornering, the forces that cause the accelerations in the two axis are in delicate balance; the last thing you want is non-uniform torque delivery as the non-uniform torque peaks will be harder to judge/anticipate, make you go over the friction threshold, and you'll slip. I'd bet that the improved traction is caused by something else.

Originally Posted by sdiver68

Another point in your analysis of smoothness as relates to M3 v 335i is that an inline engine is inherently more smooth than a Vee. Inline 6's are dynamically balanced and free from 1st and 2nd order vibrations. V's are not balanced.

This is a good point. Clearly, there is a lot more to engine smoothness than the NA vs. Turbo discussion. Regardless, what I've said about uniform torque output and response lag of a turbo engine are not theories. They are observable and measurable facts. No point in refuting that really. On a similar note, have you driven an electric car? They are damn smooth because electric motors do not rely on combustion but on the flow of electrical current instead...But I do see your point about what happens at the wheels vs at the shaft.

[swamp2]

Originally Posted by lucid

On a similar note, have you driven an electric car? They are damn smooth because electric motors do not rely on combustion but on the flow of electrical current instead...But I do see your point about what happens at the wheels vs at the shaft.

I think you have this one wrong. Electric motors and therefore electric cars are both smooth and driveable but for different reasons. They are smooth because they do not have so much offset and reciprocating mass moving at such high speeds - they are better balanced than an I6 or V8 or other std. IC designs. They are also psychologically smooth because they are quiet. They are more driveable because their torque curves are totally flat begining at 0 rpm up to a high rpm (5k or so on a good electric car motor). I really think that smoothness of an ICE is controlled largely by the extent to which it is naturally balanced and mechanically balanced with dedicated balancing mechnisms, counter-rotation etc. Whereas driveability is solely determined by the size and shape of the torque curve.

[footie]

I know this is off topic, but have any of you seen the future designs for braking. I remember seeing one design which used electronic margets to slow the car, they never wear out and their braking force depends on the size of the marget and the amount of current. Don't ask me how it works.

The other one I saw was two disc combined instead of one, clearly two the braking surface so the discs and calipers were smaller and lighter.

[UltimateBMW]

I've heard of the magnetic brakes. They aren't so far off as I recall some Merc car equipped with them. I'll do alittle research and try to find it.

Edit* After alittle looking it seems it is more magnetic suspension than brakes. A quick google search yielded info on the Audi TT, Ferrari, and a Corvette Z06 using the Delphi Magnetic suspension.

[lucid]

Originally Posted by swamp2

I think you have this one wrong. Electric motors and therefore electric cars are both smooth and driveable but for different reasons. They are smooth because they do not have so much offset and reciprocating mass moving at such high speeds - they are better balanced than an I6 or V8 or other std. IC designs. They are also psychologically smooth because they are quiet. They are more driveable because their torque curves are totally flat begining at 0 rpm up to a high rpm (5k or so on a good electric car motor). I really think that smoothness of an ICE is controlled largely by the extent to which it is naturally balanced and mechanically balanced with dedicated balancing mechnisms, counter-rotation etc. Whereas driveability is solely determined by the size and shape of the torque curve.

Well, there is a very simple test. Drive a 4 cylinder and then an 6 cylinder engine of similar design. You can do that with two current 3 series cars (not in the US). I've done the 4 vs 6 cylinder comparison. You will definitely see the difference regarding torque output, and how much smoother the 6 cylinder feels. I don't think that was happening because the 4 cylinder was more balanced than the 6 cylinder as I believe they were both inline layouts.

What you are saying about electric motors are true, but they don't mean that what I am saying is false--again uniform torque delivery matters and electric motors deliver torque much more evenly over time compared to IC engines. Have you seen torque output graphs of an IC engine vs crank angle and the difference the number of cylinders make? The flat torque curve over rpms is a separate yet relevant issue. That's not what I am talking about. I am talking about operating the engine at constant rpm to make the point. Also, the effects of reciprocating masses are manifested in the uneven torque delivery of an IC engine. Those forces are experienced in the shaft and reflected in the torque output. Apart from that, if an engine is not mechanically well balanced, it will vibrate and all that, but how much of that is "felt" at the wheel is another question and depends on the design of the rest of the drivetrain.

[sdiver68]

Originally Posted by lucid

Drive a 4 cylinder and then an 6 cylinder engine of similar design. You can do that with two current 3 series cars (not in the US). I've done the 4 vs 6 cylinder comparison. You will definitely see the difference regarding torque output, and how much smoother the 6 cylinder feels. I don't think that was happening because the 4 cylinder was more balanced than the 6 cylinder as I believe they were both inline layouts.

Inline 4's are not inherently balanced, neither are most inline 8's but they can be timed for inherent balance. Only inline 6's and up are (or can be timed to be) free from 1st and 2nd order vibrations. Also, most boxer configurations, which explains Porsche.

FWIW, Swamp brings up a good point. You can "smooth" almost any reasonable engine with balancers, counterweights, heavy flywheels, etc... but all those things add weight.

[lucid]

Originally Posted by sdiver68

Inline 4's are not naturally balanced, neither are inline 8's. Only inline 6's (and I think 12's if there were such beasts) are free from 1st and 2nd order vibrations. Also, some boxer configurations, which explains Porsche.

FWIW, Swamp brings up a good point. You can "smooth" almost any reasonable engine with balancers, counterweights, heavy flywheels, etc... but all those things add weight.

Balancing a glass on an engine is not what I mean my "smoothness" although that surely is felt. I am talking about smoothness in torque output/power delivery. Maybe I should have said uniform torque delivery at any given rpm from the beginning to avoid this. You will feel that. If cost and weight were not issues, BMW could have kept the displacement the same, and made this a V12 with smaller cylinders. That would have been really uniform torque delivery in that sense. Believe me, you would have liked it.

[sdiver68]

Originally Posted by lucid

Balancing a glass on an engine is not what I mean my "smoothness" although that surely is felt. I am talking about smoothness in torque output/power delivery. Maybe I should have said uniform torque delivery at any given rpm from the beginning to avoid this. You will feel that. If cost and weight were not issues, BMW could have kept the displacement the same, and made this a V12 with smaller cylinders. That would have been really uniform torque delivery in that sense. Believe me, you would have liked it.

OK, but let me ask this...

Would an inline 4 running at 16.2K rpm be smoother [as you are defining it] than a V8 running at 8K?

[lucid]

Originally Posted by sdiver68

OK, but let me ask this...

Would an inline 4 running at 16.2K rpm be smoother [as you are defining it] than a V8 running at 8K?

Good question, but a strange and not particularly applicable comparison since my point has been about similar (effective) displacements from the very beginning. In your example, one engine would have considerably more power than the other one if that's the case. (You can argue that a boosted 3 liter 335 engine effectively acts like a larger, say, a 4 liter M3 engine, by burning fuel at a relatively similar rate and judging by similar power outputs--I assume a boosted 335 engine will approach or exceed 400hp).

The engines in your example should be delivering the same number of power strokes per unit time. However, assuming they have similar total displacement, if you look at their torque vs crank angle charts, the torque profile of the 4 cylinder will still look less even than the torque profile of the 8 cylinder due to the larger displacement of each cylinder in the 4 cylinder engine. (Even defined by the difference between minimum and maximum torque output at constant rpm). In other words, for the 4 cylinder, a less uniform pattern will be repeated to achieve the same number of power strokes per unit time the 8 cylinder is doing.

[footie]

Knock me down here for being stupid, but I would have thought that it's not important as to how many cylinders are in play but to the amount of times the crank is turning. So if I am right then a 4cyl engine is working way harder at 16000rpm than a V8 at 8000rpm.

[sdiver68]

Originally Posted by lucid

Good question, but a strange and not particularly applicable comparison since my point has been about similar (effective) displacements from the very beginning. In your example, one engine would have considerably more power than the other one if that's the case. (You can argue that a boosted 3 liter 335 engine effectively acts like a larger, say, a 4 liter M3 engine, by burning fuel at a relatively similar rate and judging by similar power outputs--I assume a boosted 335 engine will approach or exceed 400hp).

The engines in your example should be delivering the same number of power strokes per unit time. However, assuming they have similar total displacement, if you look at their torque vs crank angle charts, the torque profile of the 4 cylinder will still look less even than the torque profile of the 8 cylinder due to the larger displacement of each cylinder in the 4 cylinder engine. (Even defined by the difference between minimum and maximum torque output at constant rpm). In other words, for the 4 cylinder, a less uniform pattern will be repeated to achieve the same number of power strokes per unit time the 8 cylinder is doing.

I agree it is strange in some sense, and really just a thought experiment and only tangentially (is that a word?) applicable to our discussion, thanks for taking the time to explain.

[lucid]

Originally Posted by footie

Knock me down here for being stupid, but I would have thought that it's not important as to how many cylinders are in play but to the amount of times the crank is turning. So if I am right then a 4cyl engine is working way harder at 16000rpm than a V8 at 8000rpm.

Not sure what you mean by working harder, but if they are of similar displacement, the 4 cylinder engine will indeed be providing significantly more power for the scenario presented. The discussion is more around how uniformly that power would be generated and applied. (Of course this is a generalization and assumes that the 4 cylinder engine can breath effectively at high rpm, and its torque output will not waste away.)

[lucid]

Originally Posted by sdiver68

I agree it is strange in some sense, and really just a thought experiment and only tangentially (is that a word?) applicable to our discussion, thanks for taking the time to explain.

No worries. That's my thinking on this anyway. But your initial point about racing is valid. In a general racing scenario, it would not make sense to trade-off more power from a given displacement for more uniform power delivery, hence turbocharging is attractive--if it is allowed. I just don't know that there is much I personally would do with more power than 420hp on a daily driver.

The strange thing is that the 335 engine is not lighter than the M3 engine (correct me if I got this one wrong). If the block was made from a lighter alloy, and the engine weighed significantly less, then one could have made the weight&handling argument.

[footie]

Well in that case then the more cylinders you add the more uniform the power delivery will be. Personally I reckon boxer engines are hard to beat, and just love the sound of any Porsche as they go north of 6000rpm but I reckon nothing will ever beat the note from a Ferrari V12.

Sorry got a little off track there.