On a 2600 pound car, 52 pounds is 2%. Add it to the front and see what happens. The hot tip in sedan racing has been as much rear weight as you can get - 54-55%. We built an SCCA American Sedan some years back and and cheated it up a bit. We moved the pedal mounts and steering column to set the driver back about 5" and closer to the center of the car. The car was actually faster with 50# added behind the right rear wheel. This flies in the face of polar moment of inertia (weight should be inside the wheelbase) and running as light as possible (we were 50 pounds heavy) but It was faster.
It's why 318's are fun. I'd love a four cylinder with 50 more rear wheel horsepower. And another thing, they stop better too.
