Edgy01

Perhaps before many of you were born Porsche began to have to bend to the influence of the EPA when they started in 1984 to install small orange "upshiift" lights on the tachs of the 911. If you shifted where they told you to shift you would never have any power production. It was all to gain higher gas mileage figures--that was all. Most Porsche drivers in those days simply pulled out the little lightbulb and continued to do as they did before--shifting higher in order to maintain sufficient power for whatever they were doing. If you shift early the rpms drop to outside the reasonable torque range for these engines when in the next higher gear. The reason to shift at a higher rpm is so that when the rpms drop for the subsequent gear, it's still capable of providing sufficient power. I'm sure that the PDK was originally programmed to deliver the best mileage possible. However, with fuzzy logic, you as the owner and driver will be able to influence the shifts points as the transmission learns your particular style of shifting and driving.

BTW, Randy Leffingwell is a good friend of mine. I dare say he knows a thing about driving Porsches. He is also highly connected with the factory and knows many Zuffenhausen secrets!

ADias

No issue there.

ADias

Mike in CA

I don't disagree with any of the opinions regarding revving the engine for optimum power, proper performance throught the gears, or just plain enjoyment. I very seldom use the auto function with PDK on the street, and when I do, I engage sport mode because it eliminates the premature shifting which I find annoying and un-sporty.

OTOH, it doesn't automatically follow that allowing the latest generation DFI Porsche engines backed by PDK to shift early, as they are designed to do in auto mode, will cause them to suffer damage or shortened life. It's possible, but since there is no evidence to back up this claim, not least because history with these engines is so lacking, it's also purely speculation.

Mike in CA

My '84 3.2 Carrera had the CASIS arrow (Computer Aided Shift Information System). I tired using it a few times just for kicks, but otherwise ignored it. It never annoyed me enough, though, to go the trouble of plucking out the bulb although I know others did!

Quadcammer

Prove it? Oh wait, you have no evidence...shocker.


Ok, get a vbox and PROVE that it pulls harder. My bet, placebo.

Please explain what you mean when you say "keeps the engine fresh". This simply has no meaning.

Does he have proof? Would anyone care to show it to me. Seems he's making a statement as if it were fact, so were is the factual back up for that.

seriously? sufficient power production? My 993TT can be driven at 25% throttle at 1500rpm all day, and it makes crap for torque compared to say a 3.8s motor.

This isn't a 356 with needle bearings...you'd have to be at about 800rpm in 4th gear before you'd be lugging the motor to a degree sufficient to be dangerous.

Perhaps zuffenhausen has taken two engines, run one hard, and the other soft, and shown that the softly driven one makes less power and has more wear.

Lets see the evidence....SHOW ME THE PROOF.

ADias

The proof is in every shop who has opened Porsche boxer engines in the last 60 years. Your ignorance about Leffingwell's credentials is telling.

It is apparent that you would be equally happy with a 4-pot Corolla engine in your car, running at a sedate 2kRPM, and would not be able to tell the difference, as you vehemently object to properly revving up the engine. AFAIC go ahead, be happy!

zanwar

I believe these are general purpose engines and they're capable of operating in many different driving modes. The key thing is to mix it up. I drive my car in 6th at 30mph all the time. It saves gas and gives the opportunity for lots of fun rev-matched downshifts.

Quadcammer

Ok, so obviously you can find even one experienced mechanic who can show me the dyno graphs or the additional wear on the motor. All I ever hear from you is bull****. Its all anecdotal. Not one hard fact or figure, or even picture. I'm tired of this nonsense. PROVE SOMETHING WITH FACTS, not conjecture.

This is not complicated.

1. Higher revs = more engine wear
2. Higher load = more engine wear

There is not one single solitary piece in a porsche engine that makes it unique to any other ICE when it comes to the above statements.

This "drive it hard to blow out the carbon" crap that gets perpetuated on forums is based on outdated vehicles that often came with carburetors that were difficult to keep synched and were not very well tuned to begin with.

A modern fuel injected engine is not fouling up the combustion chambers with excessive carbon...it just isn't happening.

As for leffingwell's credentials, this is from his own website:

Photographer and writer, Randy Leffingwell, has more than 30 books in print, primarily on Americana subjects. These cover interests and areas as diverse as the American barn and Harley-Davidson motorcycles, California’s wine country and John Deere farm tractors. His awareness of and attraction to cars, trucks and other moving things goes back as far as he can remember, to the first Dinky Toys and Match Box cars his father and mother gave him. His practical introduction to real sports cars came a few years later when his uncle took him to watch a weekend of racing events at Meadowdale International Raceway in suburban Chicago.

Throughout all this time, however, he imagined himself becoming an architect and his life-long admiration of buildings and design began with frequent trips to downtown Chicago. While in undergraduate studies at Kansas University in the architectural engineering sequence, he discovered photography and scarcely looked back as he shifted his major studies from architecture, through English, Art History, psychology, and finally to the William Allen White school of Journalism for a BS in photojournalism.

Following graduation from KU, Randy began a successful career as a photojournalist first at the Kansas City TIMES, then joining the staff of the Chicago SUN-TIMES where he remained for nine years. He then worked as associate editor at AutoWeek magazine in Detroit, before being hired by the Los Angeles TIMES as a writer/photographer. He worked for the TIMES for 11 years, covering everything from news stories to personality profiles to food features throughout Italy, film festivals in France and Utah, and live theater in London. It was, he says, a great job and a great place to work.

It was over thirteen years ago when he began his first book project. He has logged more than 600,000 miles on photographic road trips throughout the United States, completely wearing out three vehicles. He estimates he’s shot something close to 15,000 rolls of film for the books.


Where does he describe his significant porsche experience? I'd like to learn, please tell me all about Mr. Leffingwell.





Now, as to your other comment. In fact, I drive my 993 all the time, and rev it to redline all the time. However, I realize that by doing so I'm creating wear, and not helping a god damn thing.

I can simply argue a point from multiple directions. For instance, I argued there is no harm in letting a car sit and driving it rarely, even though I don't personally do this.

On the other hand, you seem like the type that spends more time adjusting your car cover than actually experiencing what the car can do...but you sure can copy and paste with the best of them.

good day sir.

ADias

^ Go ahead and continue with your insulting posts or just ignore my 'BS'.

997, esq

Manual says that you should shift to a lower gear when revs are below 1500 rpms. I agree with the above statements that it would be rather stupid from a business and legal perspective to encourage driving habits (or design a PDK transmission) likely to cause failure of the engine. As I understand it, early 911s / aircooled VWs suffered significantly if they were lugged. So, this could be a product of outdated thinking. At any rate, I don't believe anything like this without evidence.


Edit -- just saw Quadcammer made many of these points. But I agree that higher revs just means more power and more wear per mile. Author of this book does not appear to be an engineer or even a mechanic.

ADias

FYI... 7th gear PDK at 60MPH runs at about 1600RPM (something I do not advise on a routine basis). See chart below:

Bob Rouleau

Gents, diverse opinions are welcome here. Insults and belligerence are not.

Thanks,

Mike in CA

The 50's era 356's and Carreras with Hirth roller bearing crankshaft were susceptable to failure caused by delayed oil changes, poor warm-up procedures, and lugging the engine in the upper gears.* I remember hearing about how dangerous it was to lug Porsche engines when I was first introduced to Porsches back in the late '60's, even though by then the plain bearing motors were much less susceptible to the problems of the earlier roller bearing versions. Not saying that lugging modern Porsche engines is good, but it's much much less of a problem than it used to be.

*Info from Excellence Was Expected Vol 1 pg.67 (a great read for anyone interested in Porsches)

Doc GTO

I had Italian cars ranging in age from 1979 to 1992. Everything from carbs, SPICA mech FI, and Bosche analog/digital FI. Same for all of them. Haven't you ever heard of the "Italian tune up!"

As far as your post above, with the choice of 2K or a 9K shift I think in the case stay with the 2K . . . LOL.