The US market SVX will never spin the rear wheels ahead of the front wheels, it is a mechanical impossibilty for the rear driveshaft speed to be higher than the front pinion gear. Any SVX will easily spin one front wheel, because the front differential is open, and power will go to the wheel with the least tractive effort. Because of the LSD in the rear, they will usually spin as a set. It is not uncommon to see a subaru like this spin three wheels on a slippery surface, or even spin only one front wheel as the overall speed between the front output and the rear output can still be the same because again of the open diff. This would not be likely to occur in the VTD system used in other markets because they have a rear bias.
On dry pavement a properly running SVX will not usually spin any of the tires because there is not enough torque to overcome the tractive effort of 3 wheels much less 4. Even in a turn.
Further, because of the active predictive modeling capability of the TCU, An SVX at more than 50 % throttle in 1st range of D gear is very near full apply pressure at the transfer clutch. In 1 range of gear 1 or 2 range of gear 2 with the manual switch on this is even more aggressive.
A LSD in the front of an SVX would help quite a bit in low traction situations, but on the average road would make no difference IF the transfer clutch is working properly which is a big if because most of them are worn, and the 92s have a problem with holding pressure.
If you had a built motor making 300 plus hp then it would be a more serious issue.
LSDs have fallen out of favor in non performance vehicles because it is easier to use the brakes to achieve the same effect and having A LSD would undermine the effectiveness of electronic stability and traction control in certain circumstances.
Oh, and by the way, no one makes a LSD for the front of the SVX, I looked. If they did, mine would have one in it
