I used to drive a lot of 1/12th scale when I lived in Germany. I was the only guy at my local track driving an RC12L3, and everyone else drove a Corally. I was consistently faster than a lot of the guys. A lot of the guys thought that it was my chassis that I was running. I got tired of hearing it, so I bought a Corally. After a couple of trips to the track, I was running faster lap times with the Corally. I was still faster than the other guys. I worked on my set-up constantly. Some of the other Corally drivers copied my set-up, and they got faster too.
The moral of this story is that a different car can make you faster, but driving a great car with the wrong set-up will make you slower. For me the Corally was a faster car, because it was easier to set-up, and drive fast than the L3, but in the hands of other guys who didn't have it set-up right, it was slower.