Replacing the bushings and springs etc will make a big difference to how to car drives, it will feel better than a new car, its a good place to start before you think about turbo charging, after all would you really want to drive a high powered front wheel drive turbo that had worn out suspension etc? It would take the fun right out of it. Start with the bushes/shocks etc and have some fun now and then look around for a turbo kit.