On Wed, 06 Apr 2016 11:01:35 +0100, Roger Mills wrote:

On 06/04/2016 04:08, Johnny B Good wrote:

====snip====


If we reconfigure the gearbox to hold the engine at its peak torque
rpm
during such a test run we will see a lower product of road speed and
thrust which corresponds to less acceleration and a slower top speed.


Indeed. But my head is black and blue from being hit against a brick
wall trying to get Mr Plowman to understand that!

Well, if Dave wishes to continue arguing otherwise, I don't see any
point in further correspondence on the matter.

The long and the short of it is that accelerating a mass is a matter of
raising its kinetic energy and the quickest way to achieve that is the
use of a range of gear ratios such that the engine operates as close as
possible to its peak BHP rpms during the change up sequence required to
accelerate the vehicle as quickly as possible.

Peak torque revs with any practical piston ICE are unlikely to produce
more than 60 or 70 or so percent of its maximum power output so that's
most definitely the wrong choice of gear change point as far as
maximizing a car's acceleration performance is concerned.

It's a pity I couldn't have distilled it to just those two paragraphs
sooner rather than later. :-(

--
Johnny B Good