Over-revs
Thread Starter
Intermediate
Joined: Nov 2012
Posts: 42
Likes: 2
From: Durham
Over-revs
I was told the prior single owner of my car was an old man that never tracked the the car and rarely drove it. Do these numbers indicate otherwise?
On other threads it seemed the consensus people with single digits in the 5 and 6 range are not accurate occurrences but glitches.
The car has ~14,000 miles now and I bought it a little over a year ago with 10,030 miles on it.
The last 1-4 over-revs must have been near the time I bought it. I don't remember any mis-shifts and worry the dealer was joy-riding it.
Number of ignitions range 1 3881 / 341.3h
Number of ignitions range 2 508 / 341.3h
Number of ignitions range 3 34 / 338.3h
Number of ignitions range 4 4 / 338.3h
Number of ignitions range 5 1 / 217.9h
Number of ignitions range 6 1 / 217.9h
Operating hours counter 442.9
Data version 00419300B7405853
Type ID DME control unit 997TUS00
Order type 997420
Country code C2
Transmission type 62702188
Transmission number G9750
Interior equipment 06
Programming operations 02
On other threads it seemed the consensus people with single digits in the 5 and 6 range are not accurate occurrences but glitches.
The car has ~14,000 miles now and I bought it a little over a year ago with 10,030 miles on it.
The last 1-4 over-revs must have been near the time I bought it. I don't remember any mis-shifts and worry the dealer was joy-riding it.
Number of ignitions range 1 3881 / 341.3h
Number of ignitions range 2 508 / 341.3h
Number of ignitions range 3 34 / 338.3h
Number of ignitions range 4 4 / 338.3h
Number of ignitions range 5 1 / 217.9h
Number of ignitions range 6 1 / 217.9h
Operating hours counter 442.9
Data version 00419300B7405853
Type ID DME control unit 997TUS00
Order type 997420
Country code C2
Transmission type 62702188
Transmission number G9750
Interior equipment 06
Programming operations 02
Pro
Joined: Oct 2010
Posts: 664
Likes: 100
From: Pasadena
Most likely not tracked. You'd see way more overrevs in 1-3, ~10x more.
But yes, definitely a missed shift awhile ago. Assuming the car runs fine now, I wouldn't worry about it.
Edit... Also there is some argument as to whether it is possible to have one ignition in range 5 and 6.
But yes, definitely a missed shift awhile ago. Assuming the car runs fine now, I wouldn't worry about it.
Edit... Also there is some argument as to whether it is possible to have one ignition in range 5 and 6.
Rennlist Member
Joined: Feb 2013
Posts: 1,088
Likes: 366
From: Edmonton, Alberta
Not possible to have only one ignition in range 5 and 6. To make it all the ways through range 5 to get to range 6, there would be multiple ignitions in range 5, and many more in range 4. Even in range 4 there was only one engine revolution. This means that even in range 4, the engine spent about 0.007 s there.
Drifting
Joined: Feb 2005
Posts: 2,248
Likes: 414
From: Coachella Valley
I've been tracking my car without generating range 1-3 over revs.
I believe this is correct. In addition to a missed downshift, range 1 over revs can be attained by full throttle starts and holding full throttle right through activation of the rev limiter. In this manner, the engine angular momentum may carry the revs into range 1 and perhaps beyond. But I'm not willing to do it just to prove it can be done 
Not possible to have only one ignition in range 5 and 6. To make it all the ways through range 5 to get to range 6, there would be multiple ignitions in range 5, and many more in range 4. Even in range 4 there was only one engine revolution. This means that even in range 4, the engine spent about 0.007 s there.
Poseur
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Joined: Nov 2005
Posts: 17,735
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From: Santa Barbara, CA
The small numbers in the upper ranges are glitches. You can't just have 1 over rev in those things.
The area that you really have to worry is when someone does what is commonly called a "money shift," which is when going from a higher gear to a lower and you select a much lower than you should have, e.g., going from 5th to 4th, but you get 2nd instead---if you fully release the clutch at that point the engine will spin up to try to catch up to the tranny speed and you will violate the 7300 rpm redline significantly, and for some time until you realize what you have done and push the clutch pedal in quickly.
When accelerating and going up through the gears it is very common to bust through the redline in 1st gear because 7300 comes up very quickly if you're not focused. The momentum of the engine can easily carry the engine to 7600-7700 rpm particularly if you have Sport Chrono and you have the sport mode engaged. (Sport mode makes from a more dramatic engine cut off at redline than the default mode does).
The area that you really have to worry is when someone does what is commonly called a "money shift," which is when going from a higher gear to a lower and you select a much lower than you should have, e.g., going from 5th to 4th, but you get 2nd instead---if you fully release the clutch at that point the engine will spin up to try to catch up to the tranny speed and you will violate the 7300 rpm redline significantly, and for some time until you realize what you have done and push the clutch pedal in quickly.
When accelerating and going up through the gears it is very common to bust through the redline in 1st gear because 7300 comes up very quickly if you're not focused. The momentum of the engine can easily carry the engine to 7600-7700 rpm particularly if you have Sport Chrono and you have the sport mode engaged. (Sport mode makes from a more dramatic engine cut off at redline than the default mode does).
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Instructor
Joined: Jan 2013
Posts: 177
Likes: 9
From: Chicagoland
My guess..
Based on numbers, the "old guy" might have driven it nicely, but it was once it got to the dealer that it got run hard. All the overrevs are very close in time. Could have be test drives, could have been sales guys, mechanics. Who knows.
But they are at a time that fits for 10,000 miles...or more accurately, 4,000 miles ago.
Based on numbers, the "old guy" might have driven it nicely, but it was once it got to the dealer that it got run hard. All the overrevs are very close in time. Could have be test drives, could have been sales guys, mechanics. Who knows.
But they are at a time that fits for 10,000 miles...or more accurately, 4,000 miles ago.
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Joined: Nov 2009
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From: PNW
I actually hit my limiter the day before yesterday. It'd been awhile but I was on a nice twisty run and a great straight presented itself. I was in Sport Mode in second gear and squeezed on the power out of a corner and my smile got in the way of the shift.
Race Director
Joined: Sep 2006
Posts: 19,031
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From: Bentonville, AR
The techs tell me is it possible. It can happen if the car is being driven at high RPMs (redline) down a hill. If the gear is high enough, the hill steep enough, gravity can cause the car to speed up and this can over rev the engine.
Three Wheelin'
Joined: Nov 2007
Posts: 1,402
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From: Maryland
absolutely possible - i've seen it first hand with my durametric on a bud's '10 track turbo.
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