From pure physics, both cars would accellerate identically. But as many have already said, there's more to racing.

On the TV show "Trucks" this weekend they were demonstrating a new power tuner from Bully Dog that will control lots of different vehicles. So they put the tuner on the pickup truck and towed a new Camaro to the track. Then they put the same tuner on the Camaro and made several runs down the dragstrip. Then they loaded a "football player sized cameraman" in the car to get some action shots. With the addition of 200+ pounds, the car was 0.2 seconds faster in the quarter mile! The only thing that suffered was the top speed. That just goes to show you that there is more to racing than horsepower and weight.