On 31/03/2016 14:25, Dave Plowman (News) wrote:
In article ,
Clive George wrote:
On 31/03/2016 01:22, Dave Plowman (News) wrote:
In article ,
Clive George wrote:
On 31/03/2016 00:43, Dave Plowman (News) wrote:
In article , Clive
George wrote:
We're not talking 0-60 times here. Just the best rate of change of
speed.

Ok. Which is achieved with the gear chosen so the engine at its
maximum power, not maximum torque.

You should join Turnip in some basic mechanical theory lessons.

The weird thing is you've just agreed with my statement in your
previous post.

At a given road speed, the maximum rate of change of road speed
will be achieved at the engine's maximum power point. The
necessary gear ratio to achieve this will be determined by the
chosen road speed and the engine's maximum power speed.

is a longer way of saying what I've just said, and you replied saying
"Yes".

Why agree with one yet disagree with the other?

Sigh. If you measure the time taken for say 5 mph increments in speed
in any one gear, the shortest time will be at peak torque. Not peak
BHP.

You decided to choose a road speed where the engine was at peak BHP in
that gear. The only way to get the same road speed at peak torque
would be by using a higher gear, since peak torque is always at lower
RPM than peak BHP.

That doesn't explain why you disagree with what I said yet not with what
Roger said. None of what you've said just there disagrees with what I
said - best rate of change of speed is achieved with the gear chosen so
the engine at its maximum power, not maximum torque.

Then you haven't understood what I've written. Many many times.

I'm not alone in this.

Or is this entire argument about you saying that the fastest instant
acceleration at all the road speeds between 0 and maximum speed will be
at the road speed where the engine is at peak torque in 1st gear?

Can I not get through to anyone that the gear used is irrelevant -
assuming it allows the vehicle to reach maximum BHP in that gear?

It would help if you weren't assuming everybody in the discussion is an
idiot. Pretty much none of the people are, not even you.

I
won't disagree with that, but don't think it's terribly useful, because
generally people are concerned with the fastest way of getting between
two road speeds (eg 20-60). And for that, the fastest way is to choose
the gear such that the engine is at or closest to maximum power, not
maximum torque. Ie change up late, not early.

The discussion was about where on the *engine's* output maximum
acceleration occurs. Not about achieving the best 0-60 mph or anything
else.

To most of the people in this discussion, the discussion is about how to
achieve maximum acceleration during normal (or rather 'spirited')
driving, at whatever start and end speed the situation requires - and
the answer to that is to choose the right gear to get as near to maximum
power as you can, not maximum engine torque.

To you it seems to be only about at which point when you're racing from
0 to whatever are you accelerating fastest - which I agree is max torque
in first gear.

Is that an adequate summary of the two positions?