Overreving possible without downshift?
11-05-2017 | 10:32 AM
#17
Rennlist Member
Joined: Jun 2001
Posts: 2,358
Likes: 311
From: San Antonio
Fahrer is correct. People who heavily track their cars have a ton of range 1 and some range 2 overrevs from hitting the redline from accelerating. No way these guys are "money shifting" just precisely enough over and over again to only log range 1 and 2 overrevs when multiple overrevs are logged in less than a second in that specific range, nor do all of these cars have a tune that eliminated or raised the rev limiter limit. One guy has even maxed out the Range 1 overrev counter where it won't log anymore of them.
I think maybe even PDK equipped cars will log range 1 overrevs and there's no way to money shift them since it won't allow the requested down shift to occur until the speed is equivalent to the redline threshold in the lower gear selected.
I think maybe even PDK equipped cars will log range 1 overrevs and there's no way to money shift them since it won't allow the requested down shift to occur until the speed is equivalent to the redline threshold in the lower gear selected.
Also, something to be aware of is that software tunes can make range 1s and 2s commonplace by raising the rev limiter. The hard-coded DME ranges stay the same, so simply bouncing off the rev limiter is racking up "over revs."
11-05-2017 | 10:47 AM
#18
Burning Brakes
Joined: Mar 2016
Posts: 1,023
Likes: 204
911 Virgin has a good article on their webpage that explains all the details including the rev ranges that are logged.
11-05-2017 | 11:28 AM
#19
Rennlist Member
Joined: Mar 2006
Posts: 6,570
Likes: 81
From: Austin
11-06-2017 | 07:50 PM
#21
Three Wheelin'
Joined: Mar 2009
Posts: 1,722
Likes: 73
From: Napa Valley, CA
We've had this discussion before. Say the rev limiter is 7,500 RPMs and you are rapidly approaching this. When your car (the ECU, that is) hits 7,500 rpms an electronic/digital signal is sent to cut fuel delivery, which is an mechanical function. But during the miniscule amount of time it takes for the ECU to register an over-rev and send the signal to cut off fuel, and then for the fuel to actually be cut off, the engine is still increasing RPMs. Thus you have a small Range 1 or 2 over-rev. I wonder for those that run right on the RPM rev limit rivet if they don't actually exceed the limit for a fraction of a second, but by slightly backing off quickly enough to just below the limit no cut-off message is sent. The only way to really know this though is to actually see the ECU coding. But think about it for a second. Why else would Porsche say that Range 1 and 2s are acceptable. I think they understand that this slight time lag exists and the resulting "over-rev" is inconsequential. But take that a step further. If the red line on your engine is 7,500 RPMs and Porshe knows that the cut-off time lag would rev the engine to a bit above this for a very short time, then is the red line really 7,500 RPMs? I mean Porsche could program the ECU to cut out at 7,300 RPMs so you would never go above 7,500 RPMs (downshifts notwithstanding). So, Porsche knows that your engine is good to a bit above the red line for that short period of time.
In the end, Range 1 or 2 over-revs aren't much of a concern, unless you get a DME that shows thousands or tens of thousands of them - and all this would mean is that the car was driven at its limit a fair amount.
In the end, Range 1 or 2 over-revs aren't much of a concern, unless you get a DME that shows thousands or tens of thousands of them - and all this would mean is that the car was driven at its limit a fair amount.
11-06-2017 | 08:20 PM
#22
Nordschleife Master
Joined: Mar 2004
Posts: 8,313
Likes: 402
From: Southwest
