What is the effect of adding weight to the front wheels of a 2WD off-road racing buggy or truck?

One part of me wants to believe that the tires, with added inertia, would spin gyroscopically providing a 4WD type pull through corners.

The other part of my believes too much weight might make the buggy uncontrollable.

people weight the wheels to balance them. Weight the chassis to balance it or also add mass (weight=traction). The front wheels of a 2wd will never simulate those of a 4wd. Many 4wd cars run clickers and one ways to feel more like a 2wd.

Weight does add traction but it also increases inertia, really depends where the weight is that matters. You still need to turn the car which is where weight really hampers performance. Weight should be something used to balance a car not something to find traction with. People do have luck using weight to "settle" a car down making it easier to drive.

Adding weight to wheels/tires is the worst possible area to add weight in an acceleration sense. Rotational mass has a greater impact on performance than static weight in almost a 1-5 ratio. General rules of thumb say that for every ounce removed of rotational mass (transmission/wheels/tires) is similar to removing 4 to 5 ounces of static weight. (chassis/electronics)

Thanks for putting that into context. I had not considered the exponential effect of weight on getting those tires spinning in the first place!