Edgy01

A basic thing that we have to understand with these engines is that although there is a cut off around redline (7300 rpms) by the engine itself (when accelerating and upshifting), these engines have a high capability to amass significant momentum. Even if you shift precisely at 7300 rpm, the inherent momentum of the engine's acceleration can easily cause the engine to race to 7600, or beyond. They rev very easily!

alexb76

I dont think it's that black and white... and have *every right* due to one mis-shift. I don't even know when this happened? could be before getting the CPO.

I remember when I was talking to dealer he mentioned they look at "how often", "how many" times the car was over-revved, and from what I've read, only range 5 and 6 void warranty, range 4 I think is more gray, dozens of ignitions in the range might be probelmatic.

alexb76

100% agreed. I see it all the time shifting at red line, as soon as you get into neutral, the momentum literally over revs the engine, almost like blipping the throttle during downshifting.

No HTwo O

Alex, it is very easy to tell when the range #4 event happend, since it is time stamped on your DME Report. Take a look. Compare that time to your total operating hours, and/or the timing of when you took possession of the car. This will give you an idea if it happened during your ownership.

Keep in mind, it is NOT your dealerships call regarding warranty coverage. It is PCNA's call.

Regardless, it's in the past. Live & learn. Move on. Enjoy.

Have fun at your track event.

blake

Great thread with lots of very good feedback. One thing you might want to do is take the DME readout to YOUR service advisor to ask for advice. Your service advisor will have experience with the local PCNA rep, and can speak to personal experience. I did this with an 07C2S that I was looking at buying back in December, and my local service rep advised against it due to personal experience with CPO warranty. That car had the following DME: 24447 R1, 4560 R2, 663 R3 and 24 R4. The service rep was worried about the continual flogging off the rev limiter in R1 and the extension into R4 range. And as we know, R4s are the "gray area" when it comes to warranty coverage with Porsche. Despite the car being in very good physical shape with excellent records, I passed...

Good luck.
-B

purrybonker

PCNA glady CPO'd my car with these numbers:

2023 range 1
103 range 2
7 range 3
1 range 4
1 range 5
1 range 6

Carrera Mike

No range 5's (and above of course)is good.

Mussl Kar

Not so sure how an engine can speed up by "momentum". Momentum is the description of an object in motion to stay in motion unless acted on by an outside source. It takes power to make the engine rotate and more power is required to make it rotate faster. If the rev limiter cuts the power at X RPMs than the "momentum" RPMs would remain at X until friction slows it down. If you throw a ball straight up in the air its V max will be the instant it leaves your hand. Ball will accelerate only from the start of the throw until you release it. How far it travels up will be a function of its final V, but it will not go any faster than the release point.

Skibum

+1

pilfjd

Finally, someone that paid attention in physics class. :-)

Jack667

I wonder if it's really that simple. Ie simple machine, etc. Don't forget that the car has complex fuel delivery, ECU, and also a flywheel.
I'm not saying one way or the other, but I would point out that simple analogies are not always accurate...
Ok, time for bed

Alan C.

I built a 944 turbo engine using an Electromotive Tec 3 for engine management. It had a lightened fly wheel and light weight clutch. When I plotted revs it showed a flat line when I bounced off the rev limiter.

Not the same car or engine management. Just a data point

Alstoy

After having owned the Porsche for about six years I do have to ask-can someone please explain what all this means? Thanks.

Skibum

It's really that simple.

blake

I won't touch the "momentum" topic... Lots of fun threads via search on this one...

The point is not to buy a Porsche under warranty with any Rev 5s or 6s, and consider 4s as gray area... 1s/2s/3s are okay, though high numbers in 1s and 2s may show abuse...

Bottom line is that these numbers are merely indicators of how hard a car has been driven, and may let the buyer know the level of stress the car has faced in its lifetime. Porsche will use these read-outs to make subjective assessments for warranty claims. Again, numerous Rennlist posts over the years validate this assertion...

-B