[lansdownplace]

A couple of points, all of the 412s were reinforced underneath as
this was required by the authorities at the time to avoid having to
re-crash the cars rather than for need. There is no noticeable
scuttle shake on my S2, I can't speak for the earlier cars although
I am told there is a very small degree of chassis flex in extremis
on the all cars from the 407 to the 412, which is absent in the
later 603/Blenheim series which are more rigid due to the amount and
location of steel in the roof and upper structure. I can't agree
with your dismissal of the effects of lowering weight, especially
lowering the center of gravity and the roll axis. Try driving any
car with a full roof box for a practical demonstration of the
effects of this. My old BMW handled significantly differently with
four passengers than two, and the shift infront/rear weight balance
from that was small but it affected the cornering and roll. Sprung
weight does affect cornering dependent on where it is, due to
increased/decreased lateral momentum and the effects of roll.
Aerodynamics have an effect over about 70 mph on cars but who knows
what the positive or negative theoretic effects of this are between
different Bristols other than by observation. As I previously noted
I am not an engineer, but I do appreciate the accumulated effects of
small changes in practice. That is, after all, why manufacturers are
always tweaking their cars. The 411 has the engine set back further
than a 407 for example which changes the yaw axis and transforms the
handling between the two cars. The 407 was 'disappointing', although
I can't personally verify that as I haven't driven a 407 so I rely
on the reports in the media and Mr Setright on that one.

Set up does matter greatly but it is the sprung weight that you are
supporting and that does affect the dynamics.

Paul