The Greddy turbo kit is about the closest thing to "bolt-on" that a turbo kit will get. The Greddy ones come with the piggy-back ECU that will make sure your fuel curve is right, and all the tubing is pre-fit as long as the kit is going on to the car it's made to fit. For example, if you're putting the 92-95 civic kit onto a CRX, you're gonna have to customize some of the tubing to make it all work.

There is additional tuning that will benefit a turbo, though. Dyno tuning and all that. So, i guess the answer is, nothing is ever "bolt-on" when it comes to forced induction. But, with a Greddy kit the parts are fit well enough and the boost is mild enough that you could bolt the kit on and drive without problems.