The only time you will have a 1:1 ratio is when you are running the same tooth count pinion/spur, and internal gear ratio is also 1:1. I don't know of any "normal" RC with a 1:1 ratio. I mean, sure, you have on-road cars with spur/diff right on the axle are considered to have internal ratio of 1:1, but I always see a pinion gear that is smaller than the spur gear being used.