I have. Not that it has lots to do with Porsches, but I held a heavy equipment operators license in the Air Force. The latest transmissions are very likely using rev-matching of the sort Nissan uses, with auto-blip if you will. The older ones were usually unsynchro'ed. We didn't need to double clutch going up the range because you pick up the rhythm of the engine, how fast it slows when you close throttle, and you time the shift to that rhythm for each vehicle. What I mean is that you disengage the clutch, move into neutral and enter the new gear just as the engine slows to the correct rpm for your road speed in the next higher gear. If pressed, you can do that without a working clutch by pulling it out of gear just as your foot coming off the throttle lets the engine slow to a no-torque-being-delivered moment. Then you put it in the next gear at just the right moment. And when you miss, you coast to a stop in neutral because you're got a snowball's chance in hell of hitting the right rpm to enter the gear without any way to disengage the clutch. I had to use that trick on a couple of old sports cars, but I'd just as soon not need again soon.

Going down the range, you always double-clutch a non-synchro box and careful drivers do it even with synchros since the periodic re-builds are a big part of the operating cost of such vehicles.

I used to race Formula Ford, including Skip Barber's cars, and that formula is not synchronized. Teaching double-clutching and timing your shifts and doing all that with heel-and-toe was a big part of the curriculum. The series at Barber now is run in their own spec cars, from Dodge last time I checked. I wouldn't be terribly surprised if they specified a synchromesh tranny on the new series in order to cut wear since they offer racing lessons to completely novices. If that's the case, someone who doesn't grasp the role of the different components in the driveline could confuse "we don't need to double clutch any more" with "we don't need to heel-and-toe any more".

[Out of curiosity, I just checked their website. "Downshifting technique" is still a big part of their curriculum, and of course you must heel-and-toe to drive a formula car of that basic sort. They don't include "auto-blip" and they sure won't add a double-clutch transmission to the series until the cost comes down by a factor of four or more. You could buy a Formula Ford outright (and surely a Formula Dodge as well) for the cost of a PDK transmission.]

Don't buy a Porsche, Rodolfo. It won't last with your driving 'teknic' and you seem determined not to learn the technique of serious drivers. You're not causing a bother, you're just not learning anything from a forum you joined to ask questions. I would be bored except that I know that when we answer seriously it helps other people who do listen. Of course, most drivers new to high performance cars notice how many instructors are on this forum and decide to pay attention. If you got the impression you did "from instructors" then you misheard them, or their true subject is Parcheesi, not fast cars.

Gary

 

Hearing the arguments on both sides, considering everything I've read, and applying my engineering sense sways me towards the opinion that downshifting shouldn't be done without at least some decent attempt at rev matching. If strong evidence (not just assertion) to the contrary can be presented, I'd like to hear it. Meanwhile, I'm not eager to experiment with my brand new $100K+ car to test its durability.

On another note, to address my other original question, I'm finding that my upshifting is getting smoother and faster as a result of slightly slower and more careful engagement of the clutch.

 

An engineering background is great for a car enthusiast.

Given your background, what are your thoughts on the rear-engine layout of the 911? Do you think it changes the way the car should be driven in terms of extent of trail braking, transition point from braking to acceleration, appropriate corrections, etc. Not that I'll be taking my car close to its limits any time soon, but it's interesting to think about these issues given how atypical the rear-engine layout is.

 

You must be right. Enjoy your future Porsche.

 

Actually, I've had lots of thoughts over the years and some startling new ones since buying our first Porsche nearly two years ago. The original 911 was downright notorious for two traits seen by laymen as artifacts of the lump hanging behind the rear axle. One was actually a result of the body form that made it practical to put the engine there. When the effective heading of the car, that is the mean air path, deviated from straight ahead, the center of lift of the body changed dramatically. Basically, it behaved like a weather vane, but not so predictably because the flow over the front fenders did not smoothly progress as the effective wind shifted azimuth. In simpler terms, people lost control in sidewinds at high speeds (for those days, say 75 to 100 mph), and cornering at high speeds could be exciting even without the stimulus of any wind except that created by motion. The other effect is legitimate though intentional. Contemporary designs were heavy to steer and inclined to high slip angles in the front without working at it. And they did work at it, to boot, because understeer was equated with 'stability' in the sixties.

Pick-up trucks clear up to the nineties were notorious for the opposite effect. Designed to handle heavy loads, yet with nothing much but a sheet metal bed in back. All the weight was in front 90% of the driving time. The complete opposite of a Porsche not being used as the grand touring car Ferdinand intended it to be.

For awhile in the late seventies and early eighties, a culture of ditch-the-tail-wagger took over at Porsche and they designed some nice cars with front engines. Very nice in a couple of cases, yet the public response was tepid at best so they fired that boss, let the corporate design culture return to its natural state and they applied technology to making Ferdinand's original ideas work with modern levels of power. Wind tunnel work forever, pragmatic testing, and bloody big tires to provide a foundation. I have friends with 911's from the eighties and their tires look like a fashion model's legs.

Oops. More later. Cindy woke up and needs me.

G

 

Okay, ten minutes for a little more. We have a generous supply of people on this forum with much more experience driving Porsches fast than myself, so remember these are just the opinions of a newby by their standards. A newby who's been around cars a long time, but still a novice with Porsches.

I expected the track behavior to be like a Formula Ford, which also has the lump behind the driver and a marked rear-weight bias. The rear suspension is behind the engine, but many people had spoken of the familiarity of getting into a FF after driving Porsches, so that was my expectation going the other way. Wasn't like that at all. I could not get the tail to come around on the race track. I hurt some feelings grumbling about "how do I get this pig to rotate?"

Finally, I reached these conclusions:

1. The eighties caused a few lawsuits and the design team were directed to find a solution to a high-performance sports car that was being given over to drivers who considered an Oldsmobile 4-4-2 to be hot stuff.

2. The early attempts at a cure exhibited limits pushed well out to the edge of practicality that provided benign understeer... until exceeded. Then the car turned around and bit. Hard. (The reputation of those models hampered my track experiments greatly. Besides a natural aversion to spinning my pretty p-car into the desert, my body isn't tolerant of that treatment all these decades since my last spin. I was tiptoeing up to the limits.) The team didn't go back to the drawing boards, they never left them.

3. The design over-compensation of past models is gone. My own experience isn't long enough to know when the transition to "modern Porsche" became so marked, but I can say that this 997 doesn't behave that way at all. I'm still learning, now that I know it isn't hiding a Jekyll and Hyde personality, but here's what I'd say so far:

a. The grip is enormous front and rear but timidity causes understeer. A late apex works best because the earlier that you put full power to the rear wheels, the better it responds.

b. Eased up to the limits, it understeers benignly all the way until you might as well be parked. It never gets bored and turns around to snap at you, but you start to think "John Deere!" more often than the car deserves. (That is, "it plows!") Drivers with actual race experience go home and grab a suspension catalog at this point. "What if I change the camber? The shocks? What about..."

c. Taken to the limits with authority, the stock Carrera S handles like a Formula Ford. In fact, I wish my Formula Ford handled this well. At my age, without a blithe young hotshot to instruct in what tests I wanted done, my heart was in my throat the first time I approached a corner at three-digit speeds betting my health on a back-of-the-envelope analysis of what the suspension was going to do. It worked. Math rules. Gulp.

I do not recommend searching for this behavior until professional training has been had. In fact, I strongly suspect the difficulty of locating this behavior pattern is intentional. Race cars are not the sort of buddy you want while playing commuter in traffic. They are too responsive for a driver with other distractions to manage. You have to know what you're looking for from other experiences, but when you do go looking, the car doesn't disappoint.

So:

Late apex even for experienced drivers except in corner configurations that make a neutral or late apex jump up and slap you in the eye.

Trust the car and especially the combined analog/digital suspension system for simple aggressive driving. The save-your-*** mode is dominant and will do its job within the limits of physics. And the seven-tenths behavior is world class sports car, not at all to be scorned.

Get professional training and you'll find a whole new level of capability. Up around nine-tenths, this car is grand. I'm sure people who've ridden with the Porsche race-drivers *** instructors at their own school can verify this out-at-the-limits behavior of the current models.

Sadly, that level is so very far out to the limits of automobile performance that no sane person would explore it on public roads. But DE days become glorious...

Gone again,

Gary