surf

Can anyone explain to me how to read the report and what falls within normal range?

Thanks

Jamie140

Type I indicate bumping into the rev limiter on the way up.
Type II indicate possible mis-shifts on the way down.

dianic

That is a rather simple way of looking at it. Here is my understanding on the general gist:

There are levels 1 to 6. Each level is I think clips of 200 rpm (or 100?) above the limiter. And the number next to it is engine revolutions at that level of rpm. So, anything above a 1 or a 2 means that the engine was over revved quite hard. It is quite seldom to have tips go above that, as in order to go higher, you would be looking at a missed shift (thus manual transmission). And if there is a missed shift, it is likely you will see type 4 and 5, or even a 6. There is also an indication when they happened (hours of operation of the engine) so if you compare relative to the total hours of the engine operation, you can determine how early in the life of a car they took place.

The higher type over revs could cause warranty issues so beware. Do a search on the forum, there is plenty of info on the subject.

911SLOW

I posted this on the gt3 forum but I altered it a bit to be applicable here too.
To calculate ignitions to seconds just change the rpm's of the example given to the 997tt ones.

DME stores number of ignitions over 6 ranges of rpm for the 997s and 2 ranges for the 996s and the operating hours of the overrev occurrence.

Ignitions are the firings of the spark plugs
On the 911 because its a six cylinder 4 stroke engine you get 3 ignitions per 1 revolution.

For example in a 997GT3.1 you divide the max rpm limit of 8400rpm with 60 seconds and you get 140 revolutions per second of the engine at redline.
Multiply this by 3 and you have the ignitions per second of the engine at redline 140x3= 420 ignitions per second on the rev limiter.
From this you can see how long *in seconds the engine stayed in a particular rpm range and also from the operating hours you can see how long ago this happened.
On the 996 GT3 with rev limiter at 8200rpm 2 types of over revs were recorded in the DME type 1 that recorded every ignition above 8201 rpm. And type 2 which recorded every ignition above 8801 and to infinity.

From the 997 introduction newer DME has the ability of recording not only type 1 and type 2 but 6 types so that the dealers can check easily not only when a type 2 overrev happened and how long it lasted but also at what range of revs.
Type 1 are stored SAME like in 996 for all 997s meaning that type 1 is very common and every one who hits the rev limiter while accelerating should have them.
Type 2 to 5 is adding 200 -300 rpm more for each range and type 6 are overrevs fe. over 9500 and to 11000 and if recorded in dme will probably void your warranty.

Hope this helps

John

dianic

John you kill me with your ever changing avatars.
Now that is what I call a scientific answer. Respect. Mine was all general and plain.
When are we having that coffee?

911SLOW

Hey Nick I am thinking to stop changing avatars now and start changing user names, more catchy ..

Coffee is a go call me anytime 24/7.

surf

Thanks for the info. I looked at a 997TT and had the report done. Results

Range 3
543 ignitions at 269.9 H

Range 4
257 ignitions at 269.9 H

Range 5
92 ignitions at 269.9 H

Range 6
o


Total operating hours =361

dianic

So I assume this is a manual? Approximately 100 hours ago, someone missed a shift... I wouldnt be too happy about it... Although I have to admit these engines are built very strong, and it doesnt mean you will ever have an issue with it. But there has been stress to the engine and the transmission. If its not the deal of a lifetime, or a rare color that you desperately want, look for something else.

Coochas

From the Durametric website:
The 6 ranges can be broken down as:
Range 1: 7300-7500 U/min
Range 2: 7500-7700 U/min
Range 3: 7700-7900 U/min
Range 4: 7900-8400 U/min
Range 5: 8400-9500 U/min
Range 6: 9500-11000 U/min

As stated above, someone did a money shift to generate those range 5 ignitions. I think it is likely that Porsche would not do a warranty repair on the engine if needed. That being said, is the car CPO???

surf

Yes,the car has a CPO. Service manager said one .25 sec rev in range 5 was acceptable. Considering it was 90 hrs ago.

jhbrennan

Turbo has different range rpms.

Coochas

Ooops, my bad. Looks like Durametric changed the numbers on their site to the GT3 ranges.
Still, I would be very hesitant to buy a car with that many range 5 ignitions. True that it might be just a quarter second but it is a seriously botched shift. There are so many good deals on used TTs out there, I would pass this one up.

dianic

Tell him to put that in writing... or walk away.

Some people make statements which could be very hard to honor when the **** hits the fan... This gets my blood pressure going...
And you think this guy doesnt have vested interest to tell you its ok that the car hit above 8000 rpm at some stage?

jhbrennan

Good idea to have as much documentation as possible especially since the car is a CPO - I'd want to make sure that the selling dealer knew that over-revs occurred before CPO inspection and that they CPO'd the car knowing that.

SleepRM3

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