If that's the case, explain to me how the Red Bull car is 6 seconds a lap faster around Spa than the Caterham car, when they have exactly the same Renault engin

If that's the case, explain to me how the Red Bull car is 6 seconds a lap faster around Spa than the Caterham car, when they have exactly the same Renault engine and the same pirelli tires. Did Caterham forget to turn their engine into fast mode? Or is there maybe some technology somewhere in that Red Bull car to justify their roughly $300 million budget.