No engine is designed to run at (or beyond) the 'redline' for any extended period of time. By extended, I mean more than a very short transitory period (1-3 seconds).
The design criteria of the engine is predicated on tested failure modes of individual parts (and failure modes of parts in concert) based on intended duty cycles.

Valve springs aren't designed to handle extended runs at the limit. Consequently, their ability to control the valves under these conditions deteriorates quickly.
Ultimately, the valves will eventually float if the engine is pushed for an extended period of time at or near the redline, due to the fatigue of the valve springs. The rev-limiter won't prevent that from happening.

How long will the springs last at the limit? That depends on how you drive the car day to day and the level of accumulated fatigue in the springs. Other factors such as accidental over-revs greatly reduce the valve spring's ability to abide that kind of abuse.

I agree with PsychoBen: This guy probably rigged his yellow box to increase his top end number.
The required engine RPM to achieve that speed is ~9400 with a stock diff and tire size.
To get that speed (considering an ~9000 RPM redline) he'd have to either have much larger tires (~265-45-17) or a diff ratio around 3.9 to 1 ... oh, and a yellow box to adjust for the corresponding error(s).
It's more likely he used a yellow box to tweak the number a bit.
Nevertheless, his tach wasn't lying ... and the rumor I heard is that he blew his motor. Rumors will be rumors though.

 

my god...

 

sexy.

 

For going that fast passing those Semi's seemed a little slow...

 

It's an old old vid -- driver is "TurboDave" (though the car's not turbo). It's a legit run to redline in 6th, i.e. 160+mph, using the downhill slope to overcome drag. Doubt that there were any shenanigans with the speedo; it's more likely just a combination of calibration error, tire wear, etc. If the true speed were, say, 164mph, then that's maybe 8% error, which is highish but easily believable.

 

that would sacre me...i cant have my little red light flashing at me for that long...my head would blow right before the engine would!!

 

For what it's worth ... my car has seen ~154 mph (open deserted roadway), and the car became more and more unstable as the speed increased over 120. 154 was very close to the limit of controllability - due to aerodynamic instability.
With a downhill run and a bit of luck he may have hit 164, but definetely not 174.5 mph.

While it may look cool to see 281kmh on your speedo ... it means nothing if it's BS. It's like saying you have a 8" crank because you started measuring from the backside of your crack.

One more thing ... it's one thing to risk your own life on an open deserted road. It's a whole different ballgame when you're playing with other people's lives.

 

i hit 145mph about two times in my Jetta 1.8t.
freakin scary. feels like cars is gonna flip over when wind blows.
really unstable. so i thought s2k would be much easier to drive at that sorta speed.