Question on Rev Limiter
04-21-2008, 02:30 AM
#1
Drifting
Thread Starter
Question on Rev Limiter
I've seen the odd reference to "bouncing off the rev limiter". At what rpm does the rev limiter kick in? If it kicks in, what are the DME implications?
04-21-2008, 08:03 AM
#2
Rennlist Member
Hi Ken,
The rev limiter kicks in right around redline (7200 rpm) although I think the precise value is affected by Sport on/off and tiptronic/manual.
There is no harm in hitting the rev-limiter which you will immediately realize because it feels like the car is misfiring or hesitating. The objective is of course to avoid "bouncing off the rev-limiter" because this is only slowing you down!
The various ranges for the DME overrevs are shown below (taken from www.durametric.de). The data count the number of ignitions (i.e. sparks) in each range.I once posted a thread in which I intentionally overrevved the car in 3rd gear and generated additional range 1 ignitions.
Many people seem to get Range 2 overrevs as well in 'routine' hard driving.
I believe that since the X51 package has a higher redline (?7400) that the number of Range 1 and 2 ignitions will be significantly higher. Someone correct me if I'm wrong.
Higher range ignitions (say 4 and above) are possible by the so-called "money shift" which can happen by inappropriately selecting a lower gear (for example shifting into 2nd when going 100 mph).
There have also been many threads about the DME scans and their significance. I think it's just the high range (>4) ignitions that are a potential warranty problem.
The 6 ranges can be broken down as:
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
The rev limiter kicks in right around redline (7200 rpm) although I think the precise value is affected by Sport on/off and tiptronic/manual.
There is no harm in hitting the rev-limiter which you will immediately realize because it feels like the car is misfiring or hesitating. The objective is of course to avoid "bouncing off the rev-limiter" because this is only slowing you down!
The various ranges for the DME overrevs are shown below (taken from www.durametric.de). The data count the number of ignitions (i.e. sparks) in each range.I once posted a thread in which I intentionally overrevved the car in 3rd gear and generated additional range 1 ignitions.
Many people seem to get Range 2 overrevs as well in 'routine' hard driving.
I believe that since the X51 package has a higher redline (?7400) that the number of Range 1 and 2 ignitions will be significantly higher. Someone correct me if I'm wrong.
Higher range ignitions (say 4 and above) are possible by the so-called "money shift" which can happen by inappropriately selecting a lower gear (for example shifting into 2nd when going 100 mph).
There have also been many threads about the DME scans and their significance. I think it's just the high range (>4) ignitions that are a potential warranty problem.
The 6 ranges can be broken down as:
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
04-21-2008, 07:09 PM
#3
Poseur
Rennlist Member
Rennlist Member
Here's how it works. As you accelerate hard up to "redline" and then you upshift you have to remember that there is a lot of momentum going as you are approaching redline. Either from the cutout kicking in or you putting in the clutch to upshift, you will carry that engine speed momentum up higher than the published redline figure. Is it doing any damage? Probably not. But Porsche will record it for you.
