Can any one explain how to read the report and what is in the range of acceptable.

Thanks

 

https://www.6speedonline.com/forums/...dme-scans.html

 

How many Revs in the 5's or 6's is acceptable?

 

as i know only range 1 and 2 are acceptable

 

any comments on this over rev report.

Range 1
10891 ignitions 358 hours

Range 2
2329 ignitions 358 hours

Range 3
543 ignitions 269.6 hours

range 4
257 ignitions 269.6 hours

Range 5
92 ignitions 269.6 hours

Range 6 total operating hours= 361
o

 

If the car had a flash that raised the rev limit you will see numbers like that.
On my tuned car I see range 5 ignitions.

 

If a flashed dme would give revs in range 5 than I assume the engine is robust enough to handle range 5 revs

 

Why would you assume that?

The 92 ignitions in range 5 indicates that the engine exceeded 7900 rpms for 0.25 seconds about 100 hours before most recent DME reading. Some range 1 and 2 revs occurred recently - about 3 hours before last DME reading - someone bumped up against the rev limiter. You have to make your own judgment about over revs. There are lots of cars available without any over revs but then again less than a quarter of a second in range 5 wouldn't bother me.

 

other why this car is very clean with a cert porsche extended warranty.

 

Not sure I understand your response - is it being sold by a Porsche dealer as a CPO car?

 

Yes it is a CPI car at a dealer

 

Surf,
There have been many threads on this topic in the past. If you search the archives you can find them.

My recollection is that a common perception is that a DME report with revs in ranges 4-6 will likely invalidate the factory warranty although the dealership and Porsche North America (or whatever that branch of the organization is called) can decide on a case by case basis. I'm surprised in any event that they would CPO a car with this report.

Regarding flashes; I'm curious to know what type of flash increases the redline enough to get you near 8,000 rpm and bring range 5 into play and if the engine internals had to be modified as well. I recently had my 997.1 TT flashed by EVOMS which increased the redline to 7,000 but even then the flash is designed to keep those revs from registering on the DME. I think the GT3 redlines at 7,900 rpm but I believe that motor is substantially different from a turbo's. I would want to receive some very knowledgeable assurances before thinking it was okay to routinely venture above 7,000 rpm in a turbo.

Generally, over revs in ranges 4-6 are indicative of a badly missed downshift like going from 5th to 2nd instead of 4th and can happen when a driver is under a lot of pressure to get multiple tasks done right away or else. Think being on a track and having to brake from 140 mph at the end of a straight and downshifting x2 for the upcoming 70 mph turn. Lots to do very quickly and smoothly and stuff can happen.

I would do some additional research. This DME report is not one I would call "clean".

 

You're right - lots of interesting discussion about this topic over the years. Couple of other comments:

1) If the DME records overrevs no flash is going to prevent the recording of the overrevs. All the flash does is increase the threshold when the rev limiter kicks in - you'll still see something in range 3 if the rev limiter kicks in at 7000 rpm.
2) Generally Porsche will not CPO a car with revs in ranges 3 or above (there's something about this on the CPO checklist)...but I've seen two instances recently where a 997TT has been sold as a CPO with revs in ranges 4,5 and 6 (although single digit and low double digit numbers). The revs were disclosed by the dealer too so it's not like they CPO'd a car without having the DME readout. CPO'ing a car with overrevs seems to be something new with Porsche dealers - maybe they've determined the engines are stronger than first thought??
3) 0.25 seconds in range 5 doesn't seem to me to be a badly missed downshift but then that's just my opinion.
4) Ultimately it will come down to the buyer's willingness to take a risk. As I said earlier there are lots of cars without any overrev history, so if the buyer doesn't want to risk engine problems and denied warranty claims, he should continue looking.

 

It looks to me that the car had one missed down shift. 90 hours ago. I don't think it a concern

 

Hey, I have a question about this analysis that you've made. I understand how 92 ignitions translated to about 0.25 seconds, ie. 7900rpm * 3 ignitions per rotation = 23700 ignitions per min, 23700ipm / 60 = 395 ignitions per second, so then 92/395 = about .23 seconds.

HOWEVER, the 92 ignitions is the CUMULATIVE number of ignitions in range 5 of the motor's life right? Not the number of ignitions of the last occurance. Thus, we can't just assume that the last occurance, about 100 hrs ago, had a duration of .25 or .23 seconds right?

Am i not understanding something?