Re: MAXIMA

[Eliot Lim <eliot@u.washington.edu>]

> I have to disagree on the comment that a V-6 is a smoother
> engine.  Perhaps at idle, but due to the straight design and the firing
> pattern of the 5 cyl engines, they will be smoother at speed.

it's possible to build a rough V6 and it's possible to build a smooth
straight five.  but if you want to compare apples to apples you will
need to consider the theory.

a straight five has an unbalanced mode of vibration in the longitudinal
axis.  audi places the engine over the front axle to cantilever this
force onto soft mounts above the gearbox area.  if you touch the gear
shift you can feel it.

they have also refined this inherently inferior design over many years
of development to the point where it is now almost as smooth as a good
six.  the dual mass flywheel is an example of such a refinement (also
used on the audi v6, btw).

a straight six or a v6 is inherently smoother than a straight 5 because
with even number of cylinders you do not have that longitudinal vibration. 
(or for that matter primary or secondary mode of vibrations)  you can
easily make it rougher than a good straight five by having poor QC and/or
design like having pistons of widely varying weights.  this is beside
the point.

audi has done better with smoothing a five than either volvo or honda.
but it doesn't mean that that a straight five is inherently smoother
than a six.  it is not and that's why the five is history now.


eliot