While both are powerful cars in their own right, the GTO's significantly larger displacement engine (LS2 V8 vs. Cobalt's Ecotec I4) and the inherent advantages of a supercharger at lower RPMs give it a substantial power advantage. The GTO also typically benefits from a better power-to-weight ratio despite being a heavier car.
The Cobalt SS's turbocharger might offer a stronger top-end punch, but the LS2's supercharger provides more immediate and consistent power throughout the rev range, leading to quicker acceleration from a standstill and in most real-world driving situations. This difference would be more pronounced in a race.
Keep in mind this is a generalization. Specific modifications, driver skill, and track conditions can heavily influence the outcome of any race.
