I hope Desmo is not going to mind, but I'll answers this, as this seems like an honest discussion.Originally posted by Wuzak
Surely if the torque peak rpm and power peak rpm are close together then you know that your engine is peaky, and you will need to have gears close together.
If they are far apart then you know that you have a wide power band, and you will not need as many close stacked gears?
But really, isn't it better to have a flattish torque curve?
To have driveable angine, it's good to have a flattish torque curve, because that way power band tends to be wider. It's even better to have negative sloping torque curve, like the electric engine has, because powerband is going to be wider still. That's why electric engine frequently requires no gears at all, its torque curve is a downward-sloping line, and hence its powerband is so wide (at expense of peak oomph) that it doesn't need several gears to be constantly in the powerband.
As for the spacing between peaks, then yes, the farther apart the peaks are, the more driveable the engine tends to be. Actually, what you have to consider are three peaks: the torque peak, the horsepower peak, and the RPM peak. Since with IC engines the last two tend to be close together, the importance of RPM peak is often overlooked. However, it's just as important as the torque peak. Once again, the electric engine is perfectly driveable, because the peaks are evenly spaced and at maximum distance from each other. Torque peak is at 0 RPM, power peak is at half the max RPM, and RPM peak is at max RPM (obviously).
That said, let's not lose sight of the big picture. Whether you talk of spacing between peaks or flattish torque curve, their importance is not by themselves, but rather by how they affect the power band. You determine the power band by simply looking the power graph. Peak spacing and flattishness of the torque curve tend to indicate something about the powerband, but the power curve actually spells it out for you in black and white.
