Someone asked for the shift points. I assume that you want them for optimum
acceleration. I have looked up some information - it is available in the
July 1988 issue of Road and Track, and the October 1993 issue of road and
track. Basically, it says:
<snip>
a car will accelerate most quickly if each shift drops the revs back to the
torque peak, regardless of where the horsepower peak may be. Often, this
means going all the way to redline - and still the revs may be too low in
the next gear.
<snip>
For example, the '85 Toyota MR2 (sorry for the non british example) has a
redline at 7700rpm, peak horsepower at 6600 rpm, and peak torque at 4800
rpm. First and second gear ratios are 3.17 and 1.90. So to shift from 1 to
two and get the maximum acceleration:
3.17
------ x 4800rpm = 8000rpm
1.90
but you really shouldn't exceed redline, so shift at 7700. The third gear
ratio is 1.31, so for the 2 to 3 shift:
1.90
------ x 4800rpm = 6960rpm
1.31
<snip>
They also mention that things get kind of screwy when you have a very flat
torque curve. As (the example they have) when you have a turbocharged car
such as a Saab turbo. For this car, the shift points are at 1 to 2 at
3745rpm and 2 to 3 at 2908rpm, as the peak torque occurs at 1950rpm. With
the flat torque curve, the shift point is definitely less important.
Phil Bates
58 MGA
67 MGB
75 Jaguar XJ12C
52 MG TD replicar (VW)
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