Originally Posted by SlotBond_007
]With my car running at 18.8 v as opposed to the normal 14.8 v wouldn’t the motor (stock E-200) have more torque available and therefore be able to run a higher gear for yet more top end speed? Perhaps changing the stock 9 tooth pinion to a 10 tooth and therefore changing the ratio from 3.0:1 to 2.7:1.
With more voltage the motor will produce more torque AND more maximum rpm. It'll also take more current and run hotter. Generally motors have a reduced life expectancy at higher voltages, but for motors with plenty in hand there is no need to worry about that.
Changing from a 9 tooth pinion to a 10 will give more top speed and less acceleration.
Changing from a 9 tooth pinion to a 8 will give less top speed and more acceleration.
Which gives better lap times?
It depends on the car and the circuit.
On tracks with short straights where the car never gets to maximum speed more acceleration may be be better.
On tracks where the car spends significant time at maximum speed, more top speed may be better.
Whichever ratio makes the car easier to drive round corners may be more important than either of the above.
The only sure answer is try it and see.