Why no rev-limiter?

Off-topic
1

Journalist blows up old codgers Porsche 917 by over-revving it:

Mr Piper’s lawyers told Judge Simon Brown QC it was agreed that the damage was caused by the over-revving of the engine to 8,200rpm, and that Mr Hales was ‘expressly warned’ to ensure the revs did not exceed 7,000rpm.

http://www.telegraph.co.uk/motoring/classiccars/9808987/You-bend-it-you-mend-it-motoring-journalist-sued-after-1.25m-porsche-engine-explodes.html

So why don’t they retro-fit a rev-limiter and arrest the spark at 7,000rpm if you could potentially cause 40k’s worth of damage by going over 7,000 rpm? Surely that has to be an economically viable modification for a valuable car like a 917?

2

Maybe because if you did that it wouldn’t be an original 917 engine?

3

It wouldn’t work, if in gear at full throttle approaching red line it jumps out of gear, there’s suddenly no resistance to huge engine acceleration and the forward momentum of the engine will take revs way past the rev limit even though the sparks may have been cut.

4

i’m guessing that for cars like that, the key criteria is to be as original as possible, any additional mods will devalue it.

that is even if it is feasible to retro-fit?

5

It’s part of the charm of old cars and the skill required to drive them. Was an unfortunate error to let a Journo loose in it.

6

Yeah - interesting - I can see both the tech and the purist reasons for not fitting it.

7

Hales isn’t just a ‘journo’.

He’s a racer with many wins to his credit. He turned to teaching fast/race driving and journalism when he got past the first flush of youth.

8

Supposedly the car was a replica and not an original 917 anyway. However, the judgement indicates that Hales admitted he did it to the insurance company and after that he’s a bit stuffed. A fuller version of events is cited on pistonheads for the interested.

9

So in conclusion, if you blow your car up and the insurer asks if it happened because you’re a bad driver - say ‘no it just blew up on its own’