The Core package will be fine. I'd bet my car that if you gave that package to the best driver int eh club he will still be faster than you or your lad over a five-minute race. If you are good enough to run the five-minute race without a single mistake, or missing a single apex, then a faster motor or better cells may well take you up a level.
Until then, tuning the chassis, learning to drive faster and being perfect for five minutes will be much cheaper ways to go faster than buying a bigger cell or a different motor. Being competitive is 90% you and 10% car. Once you are competitive, winning is 90% car and 10% you. If, like the rest of us, you and your lad are not budding World Champions, you will find like the rest of us that the Core gear is fine and a great way to get into the wonderful world of RC. HTH
