My now 31 year old younger son and I raced R/C cars together from the time he was about 7-8 years old until he was about 15. We had a blast. It was a great way to spend time together, and for him to learn something. He learned how to work on things but, more importantly, he learned sportsmanship and cooperation.
We raced at a local indoor carpet track in the winter, running the classic 1/12 scale pan cars, four cell with stock motors. We ran the 1/10 scale touring car class as well, with six cells and stock motors. Our cars were all Associated.
We ran outdoors in a Lowes parking lot in the summer, running 1/10 scale gas touring cars. That's where we really had fun, with 45 minute mains that required pit stops for refueling, something we couldn't do with the electric cars.
I wish I had more photos. Here are our gas touring cars, mine is the blue one. We were restricted to three port .12 ci engines, but I wound up adapting a .26 ci four cycle airplane engine. That thing sounded just absolutely awesome.
At this point we were well down that "slippery slope", and it was costing me a good deal of money. We were looking at stepping up to 1/8 scale, which is really the pinnical of R/C car racing. Looking at the costs, however, it struck me that it would actually be cheaper to put him in a go-cart. Fortunately, we never got that far, with him having purchased his '68 912 at the ripe old age of 14. As we worked towards converting it into a 911, the R/C car racing fell by the wayside and I sold everything to a buddy at work who had three young boys.