[MTron]

Basically, a higher revving engine is better for some applications and worse for others, it really depends on what you want, but in general, all things being equal, making the same power at a higher rpm is better

There are 2 ways to make good torque at the back wheels.

1. A really torque'y engine or
2. sacrifice rpm's for increased torque, as you gear down an engine, the rpm at the wheels drops, and the applied torque increases...its like a lever, a bigger lever allows you to have lots of leverage, but you have to move to farther to get the same result. The same applies to engines

Also since horsepower = (Torque x rpm)/5252 you will make more hp at higher rev's, allowing you to gear the rpm's down to multiply your torque.

However, certain problems can be run into, first, high revving engines are more complex and costly, as they must be finely tuned and balanced as well as made of strong lightweight components to handle the high rpm's. Also, the vast majority of high rpm engines dont have a very flat torque curve, this is due to the type of camshaft they use that allows them to make power at high rpm's. Techniques such as VTec try to work around this by having different camshafts for different rpm ranges. Because high revving engines have a very narrow "torque band" their power peak is also very narrow (see equation above).

All this equates to two very different engines, if you go with a low revving but very powerful engine you have a very broad torque curve, allowing for good acceleration and driveability at all rpm ranges, a good example is the tv show "top-gear" and their short on the Corvette Z06 going from stand still to 150mph (or somtin) all in 5th gear, a wide torque band allows this.
The high revving engine could probably not do this at all, but if you keep the engine in the torque peak/power peak then you can really thrash it around, and because the torque perk occurs at such a high rpm, when you gear it down, you make even more torque at the wheels

eg lets take the z06 transmission that has a .56:1 6th gear

400 lb/ft at 8000 rpm ->6th gear -> 14 285 rpm and 224 lb/ft at the drive-shaft
400 lb/ft at 6000 rpm ->6th gear -> 10 714 rpm and 224 lb/ft at the drive shaft

as you can see the overdrive 6th gear of the transmission increased the rpm of the drive shaft but decreased the torque, but the higher revving engine has more rpm's in the driveshaft, so for the same speed of the drive shaft, we can change the ratio a bit and the higher revving engine will have more torque in the drive shaft

400lb/ft at 8000 rpm, with a .746:1 transmission ratio, will give us 10 714 rpm (same as the 6k rpm engine above) but it now has 298.4 lb/ft available

all this means, at the same speed, the higher revving engine will put more power to the wheels then the lower revving engine, but all at the cost of having a very narrow power band