DrJupeman

I recently picked up a 2014 base Cayman 6 speed. It had ~40k miles on the clock. It will be used as a 3 (maybe 4) season daily driver and beginner DE car for my son and reintroduction to DE car for my wife (the infamous FoodAngel here on RL). They have both also now autocrossed the car, too (came in first and second in their class, beat some other Caymans and Boxsters, yay).

Before I bought the car I ran a rev report on it and it had zero over revs. I thought this was nearly impossible in such a fun machine, but, hey, good for me as the potential new owner, right? My thought when viewing this was the axiom you read on RL all the time, "damn, the previous owner literally saved his girlfriend for me. This car is basically a virgin."

A week or so after bringing the car home, my son is at Watkins Glen with it doing his first-ever DE. I was his trusty instructor so I was able to observe the treatment of the car the entire time. There were a few instances where it sounded like he kind of zinged the motor when executing his heel and toe downshifts (in this case, executing the downshift too soon, before the car was properly slowed). "Sigh, there goes the virgin," I thought.

So today I wandered out to the garage to re-run the rev report and here is what it showed. This is after 2 days @ Watkins Glen and two drivers sharing the car at one autocross (not to mention me taking it for a session at Watkins Glen and tooling around with it on the street):



Okay, so practically nothing, right? Nonetheless, I decided to do a bit more research because I can't remember what the ranges mean for each of the Porsches. So I used this site as my guide: PDF with Over Rev ranges I am happy to be corrected by anyone here if the information in this pdf regarding the range values is incorrect. To spare you from looking at the pdf, they list Range 1 over-revs as: 7200-7500, Range 2 as: 7500-7700, and Range 3 as: 7700-7900.

Assuming those ranges are accurate to what the computer reports, it led me to wonder a few things. Firstly, what really is the redline of this car? According to the gauge, it says 7,600:



According to the manual, the car makes maximum power at 7,400 (nicely close to indicated redline, I might add!) and the not to exceed engine speed is 7,800. I take the 7,800 to be where the rev limiter kicks in and therefore true redline..



The point of my post is this:

Range 1 and Range 2 are below redline. Which means if you are operating the engine in its acceptable range, under the rev limiter, you are going to accumulate a lot of these. Further, in the case of this lowly base 2.7 Cayman, if you want to ring out maximum power, you are going to be operating the engine in Range 1, period. So if you want to use all the horsepower the good engineers at Porsche designed for you, you will be accumulating Range 1 "over revs". If you drive the car within its defined operating envelope, you will be accumulating both Range 1 and Range 2 "over revs".

Maybe I have not been around Rennlist enough lately to know that maybe I am stating something blatantly obvious to everyone today. But my realization on this just now compelled me to post. In short, I bought a car whose previous owner had never even maxed out the power that the engine was designed for. I have also concluded for myself that looking at Range 1 and 2 for this motor is pretty pointless, other than it gives you a sense of whether the car has been tracked or not. As Jerry Woods taught me in his engine rebuild class all those years ago, "Revs and heat kill motors", so definitely knowing that the car has had a tough life in the upper rev range is nice to know, but I think this Range 1 and 2 information is not "over revs". Or, the information I'm using is not correct for what the ranges really are.

For those into this kind of thing, here is my son's fastest lap from his time at WG. Although Harry's lap timer is a bit slow on the update from the OBDII reader, it does show you one sampling of revs. Even eyeballing this, you'd expect more over revs (if the ranges I found are accurate):


Here's one from my single session in the car (demo run for son, I wasn't driving in this event otherwise). Again, the revs reported from the OBDII reader to Harry's are a bit delayed, but you can see I hold revs in the "over rev" range (below redline) for almost human-countable seconds. In one lap. Yet the over rev report says the car has spent no more than .175 seconds above 7200 rpm... (Again, I want to know what the real "over-rev" ranges are for this car...)

vracer

Thanx, Doc; as a newbie, this is the most cogent piece I have read on the subject. I have zinged a few in my day, but I'm still looking for an explanation on how a PDK car can overrev.

fhp911

Hey! Forget the WGI laps. Is that Dad playing the Waldstein?

If so, you've got my admiration bigly!!

Marine Blue

Range 1 & 2 for the most part are not considered an issue. It means the previous owners have used the car as intended IMHO. I have several range 1 on my Spyder and oil reports always come back perfect.

The money shift is what you need to worry about in these cars.

DrJupeman

No, that’s my son playing the Waldstein. That was a good weekend for him: Saturday he plays the Waldstein at a recital, Sunday he’s en route to his first DE at Watkins Glen, nonetheless.

fhp911

Next to the Hammerklavier and the Nurburgring!!

Stan987.2

Here is a great article that tackles most of your questions http://www.911virgin.com/porsche/rev-range-information/

fhp911

Yes!! A great article