Over-rev on stage one
#1
Three Wheelin'
Thread Starter
Over-rev on stage one
I just got my Durametric and was playing with it.
On my 997.2 (manual transmission) it shows over-rev in range 1 with value 561.
How do I interpret this value into actual engine rpm?
The rest of the range all show zero value.
How to cross-ref value of 561 to the actual engine rpm ?
How do I interpret this over-rev value and is it something good, bad or ugly ?
On my 997.2 (manual transmission) it shows over-rev in range 1 with value 561.
How do I interpret this value into actual engine rpm?
The rest of the range all show zero value.
How to cross-ref value of 561 to the actual engine rpm ?
How do I interpret this over-rev value and is it something good, bad or ugly ?
#2
Rennlist Member
That car was babied. It's my understanding that range 1 occurs when you tickle the rev limiter. If you slam into the limiter you can get some range 3's.
This typically happens when you're in second gear and mashing the accelerator and it just revs faster than one can react.
This typically happens when you're in second gear and mashing the accelerator and it just revs faster than one can react.
#4
RL Community Team
Rennlist Member
Rennlist Member
There's a difference in the values for each overrev range between the 997.1 and 997.2 cars. Range 1s aren't anything g to worry about in either generation. I don't see in your display the total operating hours which is helpful to see how long ago those overrevs occurred.
As cosmos said, your screen also looks much different than my Durametric pro readout as well. Maybe I need a software update.
As cosmos said, your screen also looks much different than my Durametric pro readout as well. Maybe I need a software update.
#5
Three Wheelin'
Thread Starter
Mine is a "enthusiast" version. I downloaded the software prior to receiving the cable. So I don't think there is any difference on the software between the "pro" and "enthusiast" version. I'm confused too when I see the "Over-rev" value in stage 1 showing "561". I think it happened fairly recently after I got the car (997.2, CS2) that the previous owner installed a set of Rennlist pedals with the extended throttle pedal for "toe & heel" shifting. Since then I've taken off that throttle plate because they were so close to the brake pedal that every time I had to brake, there was a tendency to step on the throttle as well.
#6
Rennlist Member
This reading means your engine reached the range 1 rpm limit (redline) at engine hour 1642.69. At an average speed of 30 mph this would be about odometer reading of 49,000 miles. Can't tell you when the over-rev occurred since your report doesn't show total engine hours. For this example, if we assume the range 1 redline is 7400 rpms, this is equal to about 124 rps and with 3 ignitions per revolution this would be equal to 370 ignitions (not rpms) per second which would equate to about 1.5 seconds in range 1 - not much time at all and range 1 events aren't a problem. Also, the range readings are cumulative, so you can't really determine if all 561 ignitions were a result of the same event - you could have had 300 ignitions at engine hour 200 and the remaining 261 at hour 1642.69. Sorry for all the math - I think I got it right.
#7
That picture is from Porsche's PIWIS software, not Durametric. It's running on a Panasonic Toughbook CF-54. The actual version of PIWIS is 37.100.020 (lower left corner in the image).
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#8
Three Wheelin'
Thread Starter
This reading means your engine reached the range 1 rpm limit (redline) at engine hour 1642.69. At an average speed of 30 mph this would be about odometer reading of 49,000 miles. Can't tell you when the over-rev occurred since your report doesn't show total engine hours. For this example, if we assume the range 1 redline is 7400 rpms, this is equal to about 124 rps and with 3 ignitions per revolution this would be equal to 370 ignitions (not rpms) per second which would equate to about 1.5 seconds in range 1 - not much time at all and range 1 events aren't a problem. Also, the range readings are cumulative, so you can't really determine if all 561 ignitions were a result of the same event - you could have had 300 ignitions at engine hour 200 and the remaining 261 at hour 1642.69. Sorry for all the math - I think I got it right.
#9
Rennlist Member
#10
Three Wheelin'
Thread Starter
The correct one from Durametric "enthusiasts" version.
#12
As others have said this manual transmission car with very few Range 1 events only has been babied. Nice find!
For reference the second photo shows the current hours on the car at 1708 hours. The last Range 1 event occurred at 1642 hours, or roughly 65 hours ago. When a car has events in the higher ranges it's preferable to see that it happened long ago, generally 50+ hours or more in the past. The thinking is if engine damage occurred from a Range 5 for example, it would show up well before 50+ hours have passed.
For reference the second photo shows the current hours on the car at 1708 hours. The last Range 1 event occurred at 1642 hours, or roughly 65 hours ago. When a car has events in the higher ranges it's preferable to see that it happened long ago, generally 50+ hours or more in the past. The thinking is if engine damage occurred from a Range 5 for example, it would show up well before 50+ hours have passed.
#13
Three Wheelin'
Thread Starter
As others have said this manual transmission car with very few Range 1 events only has been babied. Nice find!
For reference the second photo shows the current hours on the car at 1708 hours. The last Range 1 event occurred at 1642 hours, or roughly 65 hours ago. When a car has events in the higher ranges it's preferable to see that it happened long ago, generally 50+ hours or more in the past. The thinking is if engine damage occurred from a Range 5 for example, it would show up well before 50+ hours have passed.
For reference the second photo shows the current hours on the car at 1708 hours. The last Range 1 event occurred at 1642 hours, or roughly 65 hours ago. When a car has events in the higher ranges it's preferable to see that it happened long ago, generally 50+ hours or more in the past. The thinking is if engine damage occurred from a Range 5 for example, it would show up well before 50+ hours have passed.
#14
So the overrev was fairly recent. A three-pedal 997 that is nine years old with 45,000 miles and had never been to the redline... Either the DME has been "wiped" (unlikely) or the prior owner(s) were atypical drivers. One thing is for certain--this vehicle has never been serviced by my local dealer... No 911 leaves that shop without a comprehensive rev limiter check
Last edited by j beede; 03-05-2018 at 11:52 AM.
#15
Rennlist Member
Pray tell, someone, what is the point of all this? Buy a DME reader whatever its name to find past overrevs on a car that one owns. And then what? Tear down the engine to see IF there is damage?
I'm not getting that one.
I'm not getting that one.