The Turbo boosters were Isaac Sumdac's inventions, used as speed upgrades for Bumblebee which he sometimes uses to catch faster characters. They seem to match Bumblebee colour scheme even though they were not particularly made for Bumblebee. At first, the Turbo boosters were hard to use for Bumblebee (because he couldn't stop them in vehicle mode) but Bumblebee seemed to get the hang of them and was almost able to out-race Blurr with them.