Over-rev question, how spurious is spurious? ...

[T2R31]

Chaps,

Hoping the forum knowledge bank can shed some light on this one....aware not a new subject, but I can't find the answer I'm looking for!!!

997 Over-revs.....I have a bit of head scratching conundrum.

Purchased my 911 about 18 months ago from an OPC.....had the DME and Borescope done as part of the sales process;

Results were basically:

RR1: 300 (ish)
RR2: 108
RR3: 2
RR4: 1
RR5: 1
RR6: 0

OPC and general consensus was all good, impossible to have 2 / 1 ignitions so would be a software glitch or similar........good stuff.


Roll on to today, for the purposes of considering renewing my warranty, I've had the DME report done again and the RR3 ignition figure has gone up to 8 ? Still single figure digits and below 10 (I've read somewhere that anything less than 10 isn't really possible?) ...

My questions/concern is how spurious can/are these DME reports/the vehicle CAN network reports?

I've driven the car very carefully, no missed gears etc.......so am convinced that the increase in RR3 from 2 - 8 must be a glitch? Is 10 ignitions even possible? And wouldn't RR4 have increased slightly too due to engine inertia?

Certainly scratching my head on this one .... I haven't ran this past my local, friendly OPC as yet.....but, judging by my readings on here tonight it sounds like my warranty renewal may cost an additional 700 for a compression test!!

Or do I just drive the car for another 3k miles and get beyond the 100hr safe zone?

Advice and experience appreciated!


Thanks,

[celticstevie]

See my stuff here
http://www.pistonheads.com/xforums/topic.asp?h=0&a...

See my pm mate, what's your current rev range data.?

This rev range ste puts a lot of people off. Happy to chat you through my recent experience. It was porsche gb who piushed things along

Edited by celticstevie on Tuesday 8th October 01:11

[Rockster]

Too bad there is not a time stamp associated with the "events". I suspect (my pet theory) is that these spurious over rev counts are used as some kind of tamper detection scheme.

This could mean that the act of reading the counts could change them, this being done on purpose.

The actual numbers are derived by some formula at Porsche which has the real readings, and what was written to the counters upon the read.

The counts, maybe even the time stamp numbers, represent some kind of encryption with the real numbers and event timestamps "buried" in the seemingly implausible numbers.