Up front, I’ll say there’s no doubt other combinations that work, but I’ll speak on what WE KNOW works, and has been extensively tested here, and run numerous times. Our focus is building strong RELIABLE power on the stock bore. All that said…
2013-16 Grom – We tested, mapped, and tuned a variety of injectors. Stay stock unless you go to the cam. At that point, the only injector we sell is the only injector we found repeatable great results with. MNNTHBX pipe, Bazzaz, cam, and Mtake took the bike from 8 to 12hp. We’ve run this combo into the ground on our own bike, and numerous others as well, and it’s proven to be rock solid.
2017 Grom – Honda went with a different injector, fuel pump, and ECU. Run the stock injector. Again, we tested a variety of injectors at length. We found no option to perform as good as the OEM injector. The combo of Yosh pipe, Mtake, Bazzaz, and cam took this bike from 8 to 12.2hp.
No matter the length you chose to go in modification, the smart guy starts with the Bazzaz (or PCV). Cut rate pricing makes cheaper options enticing, but these two simply work the best, and by a large margin. Beyond that, take the time to learn and understand the capabilities of the tuner. Tuning is a simple task one you learn the basics, and the rewards are greatly increased power, flexibility, and safe operation.