exactly. Are these cars built for that? Yes. Do I want my car to have that kind of history...call me risk averse, but no, I don't.

 

The trick is that the original owner sells the car to the dealer and you contract with the dealer to buy the car. It's a legitimate CPO process. You are buying from the dealer and whether the dealer gets the car in trade, from the auto auctions, from Porsche, etc. is irrelevant. Of course you need cooperation, but it's been easy for me and others to get, especially if the original buyer has a good relationship with the dealership.

 

Slider,

Since you're in the bay area, did you look at this? It's a private seller.

I was very close to buying this car - but didn't want to fly down to the Bay Area to look at it. Looks really clean, has aero kit (which I wanted too), low miles... You're closer than I am. Ended up buying a 09 C4 leftover.

 

small world...I'm having the owner do a PPI this afternoon. did you make an offer?

 

I agree, and another thing people overlook is these reports are the maxima. That is, each line is a single event, but the system records the event that caused the longest time in each range. So this car has spent nearly two minutes in range one on a single occasion. But we get a better picture by looking at the engine hours at which that occurred, what we call the Hobbs in light aircraft.

The two-minute event happened at 1027 hours into the engine life. The next line is only one operational hour previous to that and he kept the engine up around 7500 rpm for 26 seconds that time. All this had to be just before he gave it to the dealer unless he lives near an Autobahn. A typical average speed is 35 to 40 miles per hour, so at 40,000 miles that engine can't be much past that 1000 hour mark even as it sits there. Makes me wonder if the factory did a 'courtesy' exchance of transmission for the dealer, so he would have a saleable car.

I think you can get these range one and two events by lingering on the rev limiter instead of shifting to the next gear, though God only knows why anybody would 'linger' with the engine roaring its guts out for a full two minutes. That isn't trying to stretch to the next corner entry without shifting. It's just insanity. I can't even picture a circumstance where I would do that.

All this is scary enough without going further. Anybody who would do that isn't a "hard driver", he's a buffoon with no sensitivity for fine machinery whatsoever. The range three and four and five events were earlier and might represent an attempt to shift from three to four and hitting two instead. Such things do happen, even to the best of us, though he seems to have done nothing to retrieve his error since it took a full six seconds to coast down from 8,000 plus to below the red line.

I once blew a shift and got a transmission replaced by courtesy of Acura. It took me less than half a second to disengage the clutch after that error and that was embarrassing enough. So much so that I offered to split the cost of the new tranny. (They turned me down and paid themselves. Factory said: "A new Acura transmission shouldn't make that noise. No matter what you did to it." Reminded me of that old chestnut about the Rolls-Royce axle.)

Dawdling for six seconds plus sounds like an intentional though senseless downshift, not a missed shift. That is, ... hmmm. Stupid is hard to reconstruct sometimes... Let's say he's at six thousand in third and decides to brake for the next corner with engine help, so he pops it into second and then lets the engine scream as he brakes. That might drive the engine that high up, though he might have to be going more like 6500 in third. Don't care enough to do the arithmetic because the event is stupid enough with that guesstimate.

I wouldn't go near a toaster-oven that driver had owned, let alone a Porsche. Glad to hear you decided against it, Slider.

Gary

 

Gary,

I has always been my understanding that the system 1) records the total number of ignitions in each rev range and 2) that the "time stamp" is the last occurence of an ignition in a particular rev range. However, you are stating something completely different from what has been my understanding.

I am not saying that you are worng, but now it makes me wonder if what I thought was true is, in fact, not correct.

I am confused!!!!

 

I can't vouch for that information personally, Gota, but I spent time with the service manager and a senior technician going over the full report for our car. The column headings on this section are consistent with the interpretation they gave me and I provided above.

Speaking as an engineer, if I were designing that recording system and had no room for both data in the memory, then I'd shoot for the version I described. My reason is that while cumulative total time spent in an rpm range has an effect as well, the time spent in a range in one episode tells me more about what damage may have been done. For one thing, it lets me correlate what I see in one range with the concurrent result in adjacent ranges. I believe that the bottom line is PCNA is using this data to make decisions on warranty coverage, so if they can't record both cumulative and max single event, then they would want the more sensitive indicator stored, the maximum single event and its time.

An example is that interpretation I provided. It is based on that explanation of the report I got from the dealer and the column headings, but for a moment assume they were right. We manage to tell from that version of the data that a major event took place. Two continuous minutes of running on the rev limiter is noteworthy and is enough time to do damage that never would arise if you touched the rev limiter for a second once a day for four months. And in the higher ranges, Porsche would just bow out of any warranty discussion in any case, but we are able to tell that this driver downshifted to a gear well above its range and let the car coast down still in that gear. I say coast, though we can't be sure, simply because six seconds is enough time to brake from speeds well above a hundred, so this didn't happen in the braking for a corner or some such thing. Six seconds is a bloody long time in a car that performs like ours do.

All that is presuming the interpretation I learned at Auto Gallery was correct. As I say, I can't vouch for it personally except to say it is entirely plausible to a deep geek.

Incidentally, while we're on this subject, can anyone find documentation for the redline for the 997.2 S engine? I infer it's about 7500 from the tach markings, but so far "about" is the best I can do. This has reminded me of that because I have 45 ignitions in the first range and I realized when I looked at the definition of the ranges that range one is the 200 rpm just below the redline. If the redline is really 7500. Might it be 7300, which is the start of range one? Does anyone know?

Gary

 

Gary, thanks for the additional information and the explination.

 

So many people forget that an over-rev can also occur when the car has been spun. When this happens, like on the track, the engine can be spun backwards (clutch not in fast enough) and the rev-limiter does NOT protect the engine in this scenario.

 

agreed...that was the thought that really put me off this car...and it would make sense to believe the car was indeed spun...perhaps multiple times

 

here's another set of DME numbers from a second car...virtually the same as the first...06 S with aero, 22,000 miles. Thanks to all the good comments so far, these seem far better.

 

That... is an interesting thought. I'm busy doing our taxes, like any slothful procrastinator this time of year, but offhand I don't believe you could do that at all, and more important I can't picture a combination of forces that would achieve it in a spin if it were possible to rotate the crankshaft backward.

Will be interested to talk about, but my 'break' is ending.[sigh]

Gary

 

Gary, good luck with your taxes. My statement is a very well know FACT. The search function will be your friend, and validate my point. This has been discussed many time on Rennlist.

 

Actually, didn't make it down to see the car. I was just about to get a ticket down there and have him do PPI - then I started searching for leftover 09 cars and found my current car. Yes it cost me more - but I wanted NAV and really was wanting the Bluetooth / iPod capability of the 997.2 / PCM 3.0. Of course now I'd be out $5K plus paint / install for the aero kit. Ah well, you gotta pick what you really want...!

Good luck.

 

Heh. At first, I thought you meant your tax statement.

As for engines spinning backward, I'm afraid I was trained as a scientist, and a scientist engineer is a doubly prickly fellow when it comes to 'facts'. The image of a modern engine spinning backward at 8000 rpm and recording ignitions in DME the while is so unlikely that no amount of interpretation of evidence by anyone else is going to convince me. I would have to instrument a vehicle, perform some tests and evaluate the data personally.

Of course, I'm probably biased because we used to make our living settling disputes between multiple sets of engineering teams who somehow found contradictory 'facts'. So pay no attention... just these damned taxes and where the hell did that file from last year go!?