Does Carrera have speed sensor & cut-off?
 

Spent all Saturday (much to wife's disgust)refinishing BBS wheels: sanding & polishing rims (hard to get consistent shade of shine), repainting spokes with Wurth silver. So this AM (Sunday) decided to head out for my favourite stretch of deserted, straight rural road. Speedometer wound up to 140mph, then all of a sudden the power cut. I looked at the tach, it was in the red, and I realised I was in 4th, not 5th. When speed dropped a bit, power came back up. My Bentley manual says nothing about a speed/rpm governor. Is there one in an '88 Carrera? Hope I have not done any damage; the car seems normal. My A6 does the same thing at 130mph: power cuts, speed falls, and power comes back.

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John C
1988 Carerra coupe
1957 Speedster replica
1997 A6 Avant

John,

According to the spec book, the maximum engine speed is 'governed' to a limit of 6520 rpm, +/- 50 rpm!

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Warren Hall
1973 911S Targa

I've don't think your car has one. You most likely hit the rev limiter when you redlined.

the computer does the rev limiting. chips raise it a bit, but without ARP, or other high strength rod bolts, i wouldn't.

On my 88 911 carrera,first time i try that top speed was 145,change the chip 155,another chip 165,after turbocharging her 175 +,so is all in the chip.Hope this helps.
Regards Juan
www.geocities.com/titos88911/MY911.HTML

Early cars had an ignition cut off built into the distributor rotor, it was a spring loaded device, the spring tension determined the cutoff. DME cars(84 up) have a fuel cutoff instead, the ignition cutoff was bad for the cats. It is supposed to be soft though, gradually ramping up in effectiveness, as the limit is approached.

Thanks for the feedback.
Last night I was reading "Tech Notes II" (Excellence), and found 2 notes about rev limits. One was an enquiry from a 964 owner who bent his valves by accidently shifting into 2nd from 5th. The other was a Carrera owner who said his performance chip had no rev limit and he went up to 7000. Bruce Anderson suggested that accidently going into the red on the up shift was unlikely to damage the engine. Damage is more likley when you shift down into too low a gear and the rpom goes way over the limit.
Whew! I shall have to be more careful.

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John C
1988 Carerra coupe
1957 Speedster replica
1997 A6 Avant