Following this thread I started to think about how optimum gearing is decided. Over the years I have read a number of posts that discuss the merits of 5 speed vs 6 speed, close ratio boxes, re-ratioed 5 speeds, changing gearing for different race circuits, but I have never completely understood. My basic understanding is that when you reach revs for peak power (or maybe just over) then you change gear and you want the drop in revs to be such that you fall somewhere near peak torque - is this correct? This would suggest that power band is an important parameter. What kind of parameters would influence the gearing choice - not just the difference in ratios but also the maximum and minimum?
It seems to me that the more power a car develops the higher the overall gearing (to achieve max speed?) yet rally cars appear to have low gearing - does this improve acceleration? Also drag race cars tend to run lower final drives than their street equivalents - for the same reason?
Please let me know your thoughts and any links to good explanations.
Thanks,
Shaun
Yellow SL #32