It's worth searching / asking on the UK SX owners' club forum, too:http://www.sxoc.com/vbb/forumdisplay.ph ... al-Section
when asking for help, it's useful to provide as much information as possible about your situation too;
- which engine (CA18 or SR20)?
- any modified parts?
- have you changed or adjusted anything on your car recently?
- have you had any similar problems before?
Driving 'too fast' won't kill your engine BTW
there must have been something else wrong to cause the engine to die suddenly.
When you start the engine, does it idle normally or is it uneven even at idle? I wouldn't expect a blown turbo to affect the idle.
I would double-check that the intercooler pipe/system is really air-tight, perhaps by dripping some soapy water on the joins and looking for bubbles. The intercooler pipework is under pressure, so needs to be securely joined to avoid a boost leak. Black smoke suggests over-fuelling which could be due to a boost leak.
I suggest asking on SXOC and providing as much description as possible of what it sounds/feels like when you start the engine up, at idle, revving it up and driving around.