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Is it possible to over rev an engine with PDK?

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Old 06-21-2014, 08:11 AM
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tigerspill
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Default Is it possible to over rev an engine with PDK?

To me this doesn't seem possible as it wont let a down change happen if the engine will over rev.
Old 06-21-2014, 08:48 AM
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mdrums
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No not possible...

Accelerating you'll just bump,off the rev limiter if you don't press the accelerator pedal into the kick down button and PDK will not allow a over rev down shift. When you hear a car has over revs that is from miss shifts when down shifting and a gear is missed for the next gear and the down shift spins the engine well past red line. PDK will not allow this.
Old 06-21-2014, 10:39 AM
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LexVan
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We've seen post here with over revs on PDK cars. Rare. But it's been done.

Range #1 and #2's.
Old 06-21-2014, 11:38 AM
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Philster
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And with PDK, it's extremely likely that the over revs were about as minimal as possible, and not really in any range that would risk damage... as opposed to scary possibilities with hoo-mans and der foot operated clutches and hand operated shifters. Possibilities are scary with full manual trans.
Old 06-21-2014, 12:17 PM
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Macster
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The word I get is it is possible. Not with a down shift at the wrong time, but by driving down a grade.
Old 06-21-2014, 02:48 PM
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mdrums
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PDK will not allow the car to over rev on a downshift...period. Up shift all you can do is bounce off the rev limiter.
Old 06-21-2014, 03:03 PM
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tigerspill
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Originally Posted by Macster
The word I get is it is possible. Not with a down shift at the wrong time, but by driving down a grade.
But would it not up-shift anyway when the revs get too high? Surely the PDK software wouldn't let it damage itself.
Old 06-21-2014, 08:36 PM
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mdrums
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Even if you were driving down the side of a mountain and say PDK will only down shift or allow you to down shift when the revs are low enough and that is not near red line...so it doesn't matter you can miss a shift and skip a gear or 2 and cause a bad range over rev...just not possible.
Old 06-21-2014, 11:41 PM
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Doug_B_928
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Originally Posted by mdrums
PDK will not allow the car to over rev on a downshift...period. Up shift all you can do is bounce off the rev limiter.
With the manual bouncing off the rev limiter can cause ignitions in ranges 1 and 2. Maybe it's the same with the PDK.
Old 06-21-2014, 11:59 PM
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gota911
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Yes, it is possible to get over revs (recorded ignitions in the ranges above red line) on a PDK car.

Mike, (mdrums) I agree that PDK won't let you downshift to a gear that would cause a mechanical over rev, or "money shift" but just as in a manual transmission car, you can and will get recorded ignitions in the over rev ranges if you bounce off the rev limiter hard enough during acceleration. Check out Alan C's. thread from last November.

Alan C - 2011 GTS PDK DME Rev Ranges Observed
Old 06-22-2014, 12:51 AM
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Robocop305
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I think you will only see it in range 1.
Old 06-22-2014, 12:56 AM
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Doug_B_928
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I hit the rev limiter in my manual and it created ignitions in ranges 1 and 2.
Old 06-22-2014, 08:29 AM
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mdrums
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Originally Posted by Doug_B_928
With the manual bouncing off the rev limiter can cause ignitions in ranges 1 and 2. Maybe it's the same with the PDK.
Bingo...just lite trips imto the rev limit range...no big deal
Old 06-22-2014, 01:41 PM
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Macster
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Originally Posted by tigerspill
But would it not up-shift anyway when the revs get too high? Surely the PDK software wouldn't let it damage itself.
If the PDK is in auto mode then yes, it would upshift.

But with the selector lever in position M (manual mode), there is no automatic upshift at the upper engine speed limit.

Thus if the driver does not back off the throttle or even if he does but the downslope gradient is steep enough the engine RPMs will venture into redline and beyond territory.
Old 06-22-2014, 05:42 PM
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Cloudspin
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On mine, bumping against the rev limiter with the PDK in manual mode does generate range 1 and range 2 overrevs. I don't know how it determines whether it will be a 1 or a 2 (duration maybe?) but it does generate both. It gets to red line right quick in lower gears and if I'm in normal mode, I have to call for an upshift well below 7400 rpm to avoid invoking the rev limiter. It responds quicker to Sport and Sport Plus mode manual shift requests obviously but it is very easy to get over 7400 in mine in Normal mode.
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