If you need proof a big turbo can make anything go fast, look no further than this video of a four door Volvo 850 running a 6.85 second 1/4 mile.

Sure, it is heavily modified, but what six second Volvo isn't? Underneath (and sticking out of) the hood is a huge turbo attached to a not even close to stock Volvo b230 four cylinder engine.

As you can see watching this video, the result is a 1300+ horsepower monster four door Volvo that is equal parts impressive and awesome.