[Porsche-O-Phile]

There is a way to get large turbos to spool quickly but it's absolute hell on them - ideal only if you're willing to trade turbo life for rapid spool. A situation where he's using it for a drag car and to make big $$$ in street races might be one such suitable application. It goes like this:

Deliberate fuel mapping to be rich "at idle" (which is set high, like maybe 3,500 RPM), then run a spark or glow plug in the exhaust header collector upstream of the turbo. The "lit off" unburned fuel causes a huge input of energy and heat into the exhaust gasses driving the hot-side turbine and forces it to spool a lot quicker. Like I said, complete hell on your components, but possibly suitable for an application like his.

There are also a myriad of games one can play with wastegates and so on, but if you want to spool a big turbo fast, you better have a way of getting a LOT of energy into it quickly. Tough to do with a small-displacement engine.