If I was to really be interested in improving the acceleration performance of my FJR, the best way to that would be to eat healthier, exercise more and drop weight. It would cost less, and I would likely get more years to ride.
Otherwise, in stock form, the FJR has a relatively flat torque curve. Flat torque curves allow for better acceleration or "roll on". This is why electric vehicles accelerate so quickly. Flat torque all the way up to the point where there is no more available power/amperage.
This is why locomotives use electric motors driven by diesel generators, flat torque at any speed. This is why my FJR can out accelerate the majority of vehicles on the highway, even hauling my butt and a trailer. No need for me to change that.
I have another bike that I play hooligan on, and after I have thoroughly pissed off the neighbors and LEOs, the FJR lets me ride and lay low for awhile out of town on a trip.
Now, back to my burger and fries............