Data stored on C7 computers
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Pro
Joined: Jun 2005
Posts: 706
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From: Western Canada
Data stored on C7 computers
Is a technician able to obtain data from the ecu or other computer in the car that will provide an owner/purchaser with how many times the engine has been over revved and by how much as well as any other meaningful information?
Saw this pre-purchase innspection video of used Porsche on Autoweek where the Porche computer provided this info.
FROM CAR LIFE - WHEN YOU SHOULD WALK AWAY FROM USED PORCHE 911...
http://autoweek.com/article/car-life/when-you-should-walk-away-used-porsche-911
Saw this pre-purchase innspection video of used Porsche on Autoweek where the Porche computer provided this info.
FROM CAR LIFE - WHEN YOU SHOULD WALK AWAY FROM USED PORCHE 911...
http://autoweek.com/article/car-life/when-you-should-walk-away-used-porsche-911
Tech Contributor
Joined: Oct 1999
Posts: 41,037
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From: Charlotte, NC (formerly Endicott, NY)
It is almost impossible to over rev a stock car during acceleration. However, it can be quite easy to over rev a manual when decelerating and downshifting at the same time. The rev limiter is powerless to stop the drive train from rotating the engine too fast when the clutch is let out in a gear to low for the speed the car is running. I know GM has refused warranty repairs on engines that have been mechanically over revved but I don't know if the evidence supporting a refusal is based on telltale engine damage or a record in the ECM.
Bill
Bill
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Joined: May 2016
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From: Planet of Apes
Most devastating over revs occur during misshift when intending to upshift.
As an example, typically engines are damaged when in 4th gear and at red line and the driver tries to shift into 5th, but instead selects 3rd. Or red lining at 2nd and wanting to go into 3rd but you go into first.
Porsches show over rev levels. Most Porsches experience level 1 over rev's. A few level 2's may be acceptable. Levels 3's and above, you are advised to walk away rather fast!
All modern cars now record their over revs and the duration of over revs. I'm not sure if Corvettes use the same levels (1, 2, 3, etc) as Porsche, but it's all recorded. With a Porsche, you can ask any dealer to run an ECU dump for you.
On my other track car, my friendly service manager once told me, "Kamran, we know exactly what RPM you have got the car up to and for how long!".
In addition to this recording, most modern cars record everything during to the last 15 seconds prior to a complete failure. This info is used by factory for warranty or claims against factory, as well as being accessible to the law inforcement agencies in case of fatality.
So the next time someone told you, the car has been only tracked a couple of times and I never pushed the car because I was in Novice, you might want to think about that...!
As an example, typically engines are damaged when in 4th gear and at red line and the driver tries to shift into 5th, but instead selects 3rd. Or red lining at 2nd and wanting to go into 3rd but you go into first.
Porsches show over rev levels. Most Porsches experience level 1 over rev's. A few level 2's may be acceptable. Levels 3's and above, you are advised to walk away rather fast!
All modern cars now record their over revs and the duration of over revs. I'm not sure if Corvettes use the same levels (1, 2, 3, etc) as Porsche, but it's all recorded. With a Porsche, you can ask any dealer to run an ECU dump for you.
On my other track car, my friendly service manager once told me, "Kamran, we know exactly what RPM you have got the car up to and for how long!".
In addition to this recording, most modern cars record everything during to the last 15 seconds prior to a complete failure. This info is used by factory for warranty or claims against factory, as well as being accessible to the law inforcement agencies in case of fatality.
So the next time someone told you, the car has been only tracked a couple of times and I never pushed the car because I was in Novice, you might want to think about that...!
Last edited by Kamran; Jan 6, 2017 at 09:02 PM.
