Over-rev report. Thoughts?
10-12-2018, 07:14 PM
#31
Whew! Ok....just some confusion. I thought I forgot how to divide. Yes there were two rev reports on two different cars in this thread. Perhaps a little QC before we post. 
10-12-2018, 07:44 PM
#32
A 997-1 DME records the following rev ranges:
Range 1: 7300-7500 RPM
Range 2: 7500-7700 RPM
Range 3: 7700-7900 RPM
Range 4: 7900-8400 RPM
Range 5: 8400-9500 RPM
Range 6: 9500-11000 RPM
my initial thought when seeing that report was that the car was driven by Grandma. Of course, now that we know it's pdk it is meaningless as many already stated. I would +1 the Range 1 or 2 being non factors and those can occur just by bouncing off the rev limiter while stopped and in neutral.
Range 3, 4, 5 are obviously what we want to pay attention too along with total operating hours and also at what hour the Range 3, 4, or 5 took place. I may be in the minority, but If I saw a range 3, 4, or dare I say, even a 5 range(although it would have to be very small # of ignitions) it would not scare me necessarily if it happened over 1000 operating hours ago. Most likely no damage was done if the car still runs strong and never showed any symptoms of over rev damage. Of course, on cars like that, I would have it inspected thoroughly and look at the maintenance history closely. There are lots of choices out there, so if you have the time and money, purchase an example that has the cleanest record, but I know many cars out there still running really strong with a few range 4 and 5's on the clock.
After speaking to a few techs, damage from an over rev to the point where metal stretches, something bends, or cylinder walls are damaged would make themselves known shortly after the over rev. Many times immediately the engine fails or shows signs of damage. The person committed to that down shift and let their foot off the clutch and boom! It is the deep 5 and 6 range #s that would definitely concern me. I would definitely walk away from those, but a 1 or 2 range... pffftt ... barely driven hard
Range 1: 7300-7500 RPM
Range 2: 7500-7700 RPM
Range 3: 7700-7900 RPM
Range 4: 7900-8400 RPM
Range 5: 8400-9500 RPM
Range 6: 9500-11000 RPM
my initial thought when seeing that report was that the car was driven by Grandma. Of course, now that we know it's pdk it is meaningless as many already stated. I would +1 the Range 1 or 2 being non factors and those can occur just by bouncing off the rev limiter while stopped and in neutral.
Range 3, 4, 5 are obviously what we want to pay attention too along with total operating hours and also at what hour the Range 3, 4, or 5 took place. I may be in the minority, but If I saw a range 3, 4, or dare I say, even a 5 range(although it would have to be very small # of ignitions) it would not scare me necessarily if it happened over 1000 operating hours ago. Most likely no damage was done if the car still runs strong and never showed any symptoms of over rev damage. Of course, on cars like that, I would have it inspected thoroughly and look at the maintenance history closely. There are lots of choices out there, so if you have the time and money, purchase an example that has the cleanest record, but I know many cars out there still running really strong with a few range 4 and 5's on the clock.
After speaking to a few techs, damage from an over rev to the point where metal stretches, something bends, or cylinder walls are damaged would make themselves known shortly after the over rev. Many times immediately the engine fails or shows signs of damage. The person committed to that down shift and let their foot off the clutch and boom! It is the deep 5 and 6 range #s that would definitely concern me. I would definitely walk away from those, but a 1 or 2 range... pffftt ... barely driven hard