|Quote, originally posted by ianacole »|
Do you feel there is a performance difference between a clutch based diff and a gear based diff (or LSD vs. TorSen) in our cars? Which do you think is more appropriate for road racing and why?
Totally different feel.
With a clutch type you can really use the throttle to steer you through the corner, with proper setup, more throttle actually pulls you closer to the apex of the corner, its quite an experience. Clutch types also spread the load more evenly across the driving wheels and can even allow for 100% lockup, where as a gear type will not. In many cases the clutch types being used are 1.5 way or 2 way diffs, this adds an extra dimension of stability and allows for very late braking into a corner. Since there is a driving force on the inside frt tire there is more resistance to keep it from locking up even under aggressive braking.
The added stability also allows for a more aggressive setup. As gear types are typically unloaded during decel the car will tend to be far looser than a clutch type during turn in.
As said above the clutch types will spin even if a wheel is airborne, so in a full race situation a clutch type would be generally preferred, ie if using curbs to help rotate the car, or in gravel situations.
In a gear type, under full power you can still have the inside wheel spinning and pushing you out and away from the apex. With a clutch type, if allowed to lock up 100% or nearly so, even under full power both drive wheels will pull the car through the corner and not necessarily just shove it off line as a gear type would.
In just about every case where a driver tests both gear and clutch types, in a pure racing manner, the clutch types are typically preferred. Gear types are usually only preferred if maintenance is an issue.
As the car is always sliding through the corner, many racers have come to prefer a spool over a clutch type, as it always ensures solid power being put down. However this is not very ideal in any low speed situation where the car is not being pitched. In low speed situations it would snap the CV joints quite easily.
It really all comes down to driver preference and what their budget allows for.
In a road racing aspect I would choose a clutch type. It lets you brake late, you can play with throttle to pull you through the corner and even into the apex, and will never have an issue if you use the curbs. I use the clutch type in my autox vehicle and have had excellent results with it as well. The amount of power you can put down in corner exit is so dramatic that my codriver and I are still trying to adjust to it even after nearly a full season.
I would probably tend to avoid a spool due to the fact that it is not the most user friendly when it comes to low speed navigation.