I think I explained all three on a RC guide I posted.
Anyway, Locked rear ball differential, spool same thing. The job of a normal differential is to allow the wheels it is connected to to turn at different speeds, this increases stability and grip. But once you lock the differential, you prevent both wheels from turning at different speeds.
For drifting, a spool in the rear is highly recommended. It reduces grip, and allows you to flick the rear out and initiate the drift more easily.
A front one way, obviously replaces the front differential. What it does, is when you're on throttle, it become a spool. But when you're off throttle, the front wheels spin independently (just like a rear wheel drive car). When you've got a front one way, you can go off throttle when you're angle is wrong, the car will flick around really quick because it's now rear wheel drive, and once you get the hang of it, you will have a lot more control then you did without it.
When you do a countersteer mod, you have three choices. Make the front wheels turn slower than the rear, or, the rear wheels faster than the front, OR, make the rear wheels faster AND the front ones slower.
Because of the small size of our cars, we cannot drift like real cars (with the wheels pointing away front the corner). We cannot drift RWD cars either. So what they do now, is they make the car a little bit RWD. Because the rear wheels spin faster than the fronts, a effect similiar to RWD is gained, and we can drift like rear cars do.
Now, how to do it to your TB03D. Since there aren't any gears specifically designed for your TB03D (the front differential gear has to be large, and the one connected to the driveshaft has to be small, the rear differential gear has to be as small as possible, and the driveshaft gear has to be as large as possible), you will have to modify ones that are made for other cars.
Currently, there are very good gears available for Yokomo cars, these can be modified to work on your TB03D. There are also some gear sets available for TT01s, but they won't give you a lot of countersteer, but it MIGHT be a direct replacement for your current gears.
Feel free to message me if you need any help =)
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If
NISMO stands for Nissan Motorsports, does
HOMO stand for Honda Motorsports?
Car Terminology Explained for the less literate:
* Understeer - Hitting the fence with the front of the car
* Oversteer - Hitting the fence with the back of the car
* BHP - How quickly you hit the fence
* Torque - How far the fence travels after hitting it.