Generally, RC hobbysists prefer fast chargers for their LiPo batteries. It will, of course, save you an enormous amount of time since it can cut charging time down to 50 percent. As a rule, fast charging has two amperage settings, which you will input to your charger.
The charger’s manufacturer will probably recommend the appropriate charge amperage. You will then have to input the recommended amperage to your charger although this could bring harm or overwhelm your battery if done incorrectly and carelessly.
My suggestion is to charger your RC car’s battery at 1C since this is the safest way to go. If you can, buy the best and most