I knew I wasn't crazy (Re: E92 M3)

[1 BAD 7]

I agree in my opinion I think they should have done that with the Z4 M coupe. They should have made it more mid-engine layout. Now I dont think most traditional layout of Porsche 911's are super good either because the engine seems to be to rear ward rather then sort of mid-enigned. On the other hand I think the layout in Boxster or Cayman seems to be a bit more forward and is sort of mid-rear rather then rear. Which allows the Boxster and Cayman to handle even sharper then the 911's without the obvious inherit disadvantages of rear engine layout.

None the less among the traditional Front engine-rear wheel drive layouts I cant think of a roadster/coupe in Z4 M's price range that is as capable on track as these two. Only exception might be Vette have the outright refinement of BMW's.

If they were really serious, they'd put the engine where it belongs.?

[Eye of the Tiger]

Suzuki Verona!? ? :P
FWD I-6!

[sportyaccordy]

While I know V6s are just more logical, you will never get a V6 to sound like this:

http://youtube.com/watch?v=cpw5H0erYkg

I would rather see BMW go with all V8s than do a V6... a 2.5L V8 would be pretty cool

[Eye of the Tiger]

While I know V6s are just more logical, you will never get a V6 to sound like this:

http://youtube.com/watch?v=cpw5H0erYkg

I would rather see BMW go with all V8s than do a V6... a 2.5L V8 would be pretty cool

What about this V6?
http://youtube.com/watch?v=JUIIkzKch7E

[Tave]

Now I dont think most traditional layout of Porsche 911's are super good either because the engine seems to be to rear ward rather then sort of mid-enigned. On the other hand I think the layout in Boxster or Cayman seems to be a bit more forward and is sort of mid-rear rather then rear. Which allows the Boxster and Cayman to handle even sharper then the 911's without the obvious inherit disadvantages of rear engine layout.

911s are rear-engined. Boxsters and Caymans are mid-engined. There is no "maybe" or "seems" about it.

[Tave]

Coming to that... an I6 is longer and purportedly smoother.? ? However, it makes for a longer hood, increasing the polar moment of inertia (if I remember correctly, this is from a competitor's ad). Why wouldn't BMW do V6s? Fine, V6s require balance shafts to remain smooth, but hey, we talking about the pursuit of ideal dynamics here.

I, for one, like the way a car looks when it has a long hood.

[Eye of the Tiger]

I, for one, like the way a car looks when it has a long hood.

Aveo?   

[Raza]

I agree in my opinion I think they should have done that with the Z4 M coupe. They should have made it more mid-engine layout. Now I dont think most traditional layout of Porsche 911's are super good either because the engine seems to be to rear ward rather then sort of mid-enigned. On the other hand I think the layout in Boxster or Cayman seems to be a bit more forward and is sort of mid-rear rather then rear. Which allows the Boxster and Cayman to handle even sharper then the 911's without the obvious inherit disadvantages of rear engine layout.

None the less among the traditional Front engine-rear wheel drive layouts I cant think of a roadster/coupe in Z4 M's price range that is as capable on track as these two. Only exception might be Vette have the outright refinement of BMW's.

Well, the 911 is considered rear engined, since the engine is way out back, and the Box/Cayman is considered mid engined, since the engine is in front of the rear wheels.

The S2000 and 350Z have a front midship placement, which is a front engine pushed pretty far back.  I don't know how the Z4 is put together in that regard, though. 

While I wouldn't touch an M Roadster, the Z4 3.0i and 3.0si are good values in their market (hard to say that about most BMWs!), the 3.0i especially.  Other than the Boxster, the regular Z4s run up against the S2000 (which would be my choice of front engined roadsters in this segment) which may be too raw for some, and it's been on its deathbed for years now, and the 350Z, which would have been my choice, were it not called soft here and there (though I find the convertible a much better argument for a Z car than the coupe), but the real reason I'd move the the Bavarian is that the 350Z Grand Touring Roadster touches the 40K mark (might even break through now), and that's too much to pay when the Z4 is available. 

If the Box S didn't work out, we were going to look at the M Roadster or 3.0si instead.  Luckily, I didn't have to reconcile that with my conscience, though, since we all know how that story ended. 

[Raza]

What's all this V6/I6 (L6?) nonsense come from?  Turbo fours (I or H) or H6s are the best engines out there. 

[red_shift]

My I6 sounds very good to me (love the feline growl) and I do love the smoothness. I also know that it is not perceptibly smoother than my 98 Accord V6 (3 liter). It's not as smooth as my current Accord's 2.4 I4. TL's 3.2 liter V6 is silky smooth and no issues with the sound of it either. (unlike, say previous gen G35 whose engine sounded ... err.. bad)

I think it's got more to do with tradition and distinction. I am pretty sure that if BMW wanted to make a V6 engine sound sexy, they could do it.

Oh Tave, a long hood looks good, but I am not sure if it realy helps the dynamics.

[red_shift]

Perhaps an I6 is inherently smoother, but it is not like most V8s or this one has agrarian qualities, clearly one of the criticisms of this car was that it was too soft.

What is wrong with a V8 in this car, it is shorter and lighter and more powerful.? They could make it a 6 but I can't think of any V6 that has this power level NA.? Of course, they could up the boost on the 335 motor and achieve more power, but they obviuosly want the V8, just like the competition.

No issues with the V8 in the M3 at all. However, a small displacement V8 to replace an I-6? say, a 3.5 liter V8 like the older BMWs? no way, that would be inefficient, as well as lack in torque if it has to be revved smoothly to higher redlines expected today. Just my guess.

[Tave]

Oh Tave, a long hood looks good, but I am not sure if it realy helps the dynamics.

I'm not sure the two have anything to do with each other.

[red_shift]

I'm not sure the two have anything to do with each other.

A longer hood = longitudinal layout of a straight 6 = more moment of inertia. (when turning, you could feel it)
A shorter hood = either a transverse layout or a V6 whose block is shorter = lesser moment of inertia.

[Tave]

A longer hood = longitudinal layout of a straight 6 = more moment of inertia. (when turning, you could feel it)
A shorter hood = either a transverse layout or a V6 whose block is shorter = lesser moment of inertia.

Not necessarily. A longer hood = a longer hood. They can choose to use the space underneath it, or not. They could build a car with no engine at all that doesn't even go anywhere and give it a hood a mile long.

[Tave]

But I'll give you that the form usually follows function, in this case.



I'm still confused by your argument. Could you explain it a bit more? Why would a longer hood/engine raise inertia (it's been too long since physics )

[red_shift]

But I'll give you that the form usually follows function, in this case.



I'm still confused by your argument. Could you explain it a bit more? Why would a longer hood/engine raise inertia (it's been too long since physics )

A long rod takes more effort to swing from an end then a shorter rod. I think that's a very rough explanation. I'm no mechanical engineer myself. 

[sportyaccordy]

Tave- ideally in a car you want the mass concentrated as close to the center of mass as possible. An inline six puts more weight away from the center of mass of the car, which makes it harder to rotate (in the case of a front engine car, more understeer). Even if two cars have the same weight distribution, if one has a V6 and the other has an L6, the one with the L6 will have a higher moment of inertia.


I'm taking a nap.

[Champ]

Tave- ideally in a car you want the mass concentrated as close to the center of mass as possible. An inline six puts more weight away from the center of mass of the car, which makes it harder to rotate (in the case of a front engine car, more understeer). Even if two cars have the same weight distribution, if one has a V6 and the other has an L6, the one with the L6 will have a higher moment of inertia.

Depending on where the engines are mounted, yes.? Keep in mind that on one end the I6 has more mass closer to the front of the car, but it also has more mass closer to the middle of the car - assuming both engines are mounted in the exact same spot in the center of the engine.



[-XXXXXX----------]? ? I6

vs.

[-- XXX-------------]? ? V6

roughly.

[Tave]

A long rod takes more effort to swing from an end then a shorter rod. I think that's a very rough explanation. I'm no mechanical engineer myself.?

But the "rod" in this case isn't the engine, it's the car, non?

[red_shift]

But the "rod" in this case isn't the engine, it's the car, non?

Sure. A longer hood with longitudinally mounted engine makes the 'rod' longer eh? I better leave it to Sporty Accordy. I believe he's the mech undergrad or something IIRC.

[Eye of the Tiger]

Leverage!

[Tave]

Sure. A longer hood with longitudinally mounted engine makes the 'rod' longer eh? I better leave it to Sporty Accordy. I believe he's the mech undergrad or something IIRC.

A long hood relative to the body effectively moves the engine back towards the center of mass and therefore mitigates the problem. The sacrifice, in that case, would not be handling but interior space, unless I'm missing something.



It seems to me like the only case where this V6>I6 would hold is if someone took the engine bay of an I6 car and shoved a V6 in the back of it. But it doesn't work that way, unless you're doing some sort of project car.

[red_shift]

A long hood relative to the body effectively moves the engine back towards the center of mass and therefore mitigates the problem. The sacrifice, in that case, would not be handling but interior space, unless I'm missing something.



It seems to me like the only case where this V6>I6 would hold is if someone took the engine bay of an I6 car and shoved a V6 in the back of it. But it doesn't work that way, unless you're doing some sort of project car.

Umm, the I-6 would hang it's length out further from the center of the car, no matter how further inside you try to shove it (without intruding on the driver's knees  ) A similar displacement V6 would protrude less longitudinally, right? That's the point SportyAccordy was trying to make.

[Champ]

Umm, the I-6 would hang it's length out further from the center of the car, no matter how further inside you try to shove it (without intruding on the driver's knees ) A similar displacement V6 would protrude less longitudinally, right? That's the point SportyAccordy was trying to make.

Right, but did you skip over my post entirely?

[Tave]

Umm, the I-6 would hang it's length out further from the center of the car, no matter how further inside you try to shove it (without intruding on the driver's knees? ) A similar displacement V6 would protrude less longitudinally, right? That's the point SportyAccordy was trying to make.

But that argument exists in Fairy-tale land. If engineers intend to use a V6, then they design a short hood, and move the engine closer to the front of the car, as you pointed out earlier. They don't take an engine bay designed for an I-6 and shove their V6 in the back of it.

[red_shift]

But that argument exists in Fairy-tale land. If engineers intend to use a V6, then they design a short hood, and move the engine closer to the front of the car, as you pointed out earlier. They don't take an engine bay designed for an I-6 and shove their V6 in the back of it.

As you say, the hood is shorter, that makes the overall length smaller. Then what exactly is the problem mate?

[red_shift]

Right, but did you skip over my post entirely?

Too many posts to respond to. I guess I did. See my response to Tave. I don't get what the problem is here.

A V6=shorter hood, are we agreed on that? If so, the car itself becomes shorter, agreed on that also?

Then, by inference, the car should handle better. What do you disagree with ? Let me now.

[1 BAD 7]

Is I-6 good for mid-rear configuration or is V6 better. One more thing despite the I-6 being longer I think BMW 3.0 liter I-6 in E90 is the lightest 6 cylinder engine compared to the Honda 3.2 liter or Nissan 3.5/3.7 liter.

[Tave]

If so, the car itself becomes shorter, agreed on that also?

No I don't.

BMW 3-Series - 180.60 inches

Mercedes C-Class - 178.40 inches

Audi A4 - 180.00 inches

They're all almost exactly the same size, regardless of engine configuration/hood length. What does that tell me? Mercedes and Audi probably use the space they save on the front end to increase interior room or trunk volume. Which, of course, is an advantage for those automakers in its own right.

[red_shift]

No I don't.

BMW 3-Series - 180.60 inches

Mercedes C-Class - 178.40 inches

Audi A4 - 180.00 inches

They're all almost exactly the same size, regardless of engine configuration/hood length. What does that tell me? Mercedes and Audi probably use the space they save on the front end to increase interior room or trunk volume. Which, of course, is an advantage for those automakers in its own right.

But we are talking about *all other things being equal* (which I thought was clearly  implied in my argument) a V6 is likely to reduce the length of the hood.  Sure, you can stuff whatever you want with the space saved, as you said, or you might not, in the interest of handling.