[PAR_WIG1350]

There are two possible ways to rectify the situation, reduce the torque required or increase the torque available.

Using 6" wheels instead of 8" is really the only way to reduce the required torque. Changing the COF probably won't do much since it still takes a set amount of force to accelerate a 150 lb robot the way you want it to accelerate. A lower COF would just reduce how large that force could be.

If 6" wheels aren't an option you could also increase the available torque by either changing the reduction or adding more motors. Adding motors will add a lot of weight and could be difficult to deal with in code if you don't have experience with similar configurations. Also, the best motor to use would be the miniCIM and if you have used even one miniCIM or BAG motor elsewhere on your bot, that option could become a hassle.

A change in your reduction might be the best option. It adds minimal weight and no complexity. The way I suggest doing this is by replacing your belts and pulleys with chains and sprockets of a greater reduction. 35 chain is the easiest to retrofit since it can tolerate imperfect tension better than 25 chain.