
It also depends on the engine block you choose, heavy duty blocks are better suited for turbos and superchargers and will prevent the engine from exploding on high boost, but performance ones add more power by themselves, a race car would have performance and drag would have heavy duty. Tuning the turbo boost on stage 3 turbo can be tricky, for a drag car you would want to close to max available but usually not full, whatever makes the most manageable power. If you want high end torque and power like in a drag car, then choose the biggest supercharger or turbo available, for a track car a smaller one is better since you won't be flooring it too much. If you can get more power with a smaller engine, then settle for it. Generally the more cyllinders the better, except avoid Diesels and keep an eye on intake options provided for each engine and also how much it increases your car's weight. You should choose the biggest vanilla engine available for highest low end torque. From personal experience, I can tell you to avoid using mod engines, they can be outdated.
