ORIGINAL: c9vev
Yeah, that is a solid spool in the bag, you can achieve the same effect by filling your rear diff with blu-tac(poster tape) as you put the cogs in.
A front one way is used by a couple of the boys at D1RC, others use it for a tighter track, it creates a handbrake style effect so if you come of the throttle as you enter the turn it will swing the rear round, some swear by it, others dont, I got an 03f and its so good it really doesn't need one tight track or not.
I just tryed this with my TT 01 I used electrical tape in both front and rear Diff and man the thing drifts great with both diffs locked up!. Plus a added advantage when it goes off the pavement into the gravel it actually has enough bite to get back on ( before It'd just spin one front and one back wheel and go no wear)