I’m not sure what the official red line is on the X51; I have never seen or heard what it was from an authoritative source, do you know what it is? I would consider you to be authoritative source as I have enjoyed your excellent Porsche related web sites and links.

I’m not even sure of the rpm the rev limiter kicks it as it always comes as a surprise when I inadvertently hit it. When I do inadvertently hit it by the time I look down at the tach that ranges have been between just north of 7,400 rpm all the way to just south of 7,600 rpm. The X51 reaches maximum hp at 7,200 so my guess is red line is 7,300 rpm and the limiter is 7,400 rpm.

I do know that I can record range 1 ignitions without hitting the rev limiter and the last time I inadvertently hit the limiter I recorded 3 range 2 ignitions so I am assuming the DME ranges are the same.

Please note that I said inadvertently hit the rev limiter. I am well aware that hitting it is not the smoothest or fastest way to drive the car.

FWIW, I ordered the Durametric software and USB interface after reading your post on experimenting and intentionally hitting the limiter and then using your Durametric software and USB interface to read the results. It is a fun tool to have.

 

This isn't true at all in my experience. I've hit the rev limiter with full throttle many times and the result is always the same - instantaneous drop in RPM and speed. It's very sudden and startling. Done it both in my 997 and my '86 911.

 

I've wondered about the X51 and the ranges - thanks for clarifying that.
As for the redline, I can't seem to find what it is for the X51 !!!! The power graph looks like it's 7400. I looked in the Porsche brochure, the main site, and the Club Coupe brochure but couldn't find it.
I wish I could go for a drive today but 1) I'm doing 'homework' and 2) it's going to rain 1-3 inches today - OMG !

 

Here I've cut and pasted what the 997S Technik documentation says about how the Motronic 7.8 applies the RPM cutoff. It is talking about the difference between sport mode and non-sport mode:

"More abrupt engine speed cut-off

To increase driving comfort a ’gentle’ cut-off is generally used when accelerating
and reaching the engine speed cut-off setting. In the process the throttle is
continuously closed when approaching the limit range for speed.
The Sport Chrono function facilitates additional acceleration potential through
the use of an abrupt engine speed cut-off by switching off individual cylinders
(injection and ignition) in a rotating fashion just shortly before the engine speed
limit. The perceptible limit of acceleration lets the driver know if an upshift is
executed too late. This allows the driver to learn how to identify the optimum
shift point with more accuracy and to take fuller advantage of the engine’s
potential for acceleration.
When the Sport Chrono button is pressed, the abrupt cut-off is active in 1st to
5th gears for the manual gearbox (without Sport Chrono function only in 1st and
2nd gears) and in the manual gate “M” for Tiptronic transmission."

To me, this means the RPMs are being controlled even before reaching the hard cutoff at 7300 RPM, and in no case are the RPMs allowed to exceed 7300. So, it seems to me that ranges 2 thru 6 could only be reached by disabling the rev limiter through modifications to the ECU flash or other means.

 

I would expect it has something to do with the rev limiter setting. In some cars it may be a 100 RPM higher than another and that could acoount for some range 2 hits. Keep in mind that at these high RPMs, a few ignitions would mean that you were in range 2 for around a .1 of a second.

 

Or doing 90mph and going from 5th to 2nd instead of 5th to 4th. Seems to me the limiter is helpless in that scenario.