dfi motor carbon build up possible
#46
The point is that Porsche does NOT always thoroughly test new systems or ideas before putting them into production. Also, I am not aware of too many cars that can spin out in a corner just for taking your foot off the gas. True, if one can adapt to this unusual tendency, it can be quite rewarding.
#47
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The point is that Porsche does NOT always thoroughly test new systems or ideas before putting them into production. Also, I am not aware of too many cars that can spin out in a corner just for taking your foot off the gas. True, if one can adapt to this unusual tendency, it can be quite rewarding.
I would be pressed to remember a car I ever cared about that didn't behave that way until the nineties came along. It was so common that it was a particular point made in the lesson plans of drivers training. "Never back off once you're in a corner. You'll just lose control of the car." Mind you, the big sedans they taught us in would slide off forward because they didn't have independent suspension, but it was still undesirable lift-throttle behavior. You had to be very careful to keep the car balanced in those days. It's still a very good idea to be careful about removing power suddenly. In any car.
When I got interested in sports cars, they were starting to come with independent suspension and instead of plowing into the rail forward, a car like that swaps ends when you lift the throttle abruptly.
What distinguished Porsches was their rear engine, which convinced innumerable twits it was the cause of the spin. It certainly didn't help stop the spin once the rear end broke away, but facilitating is not the same as causation.
Those Porsches were in fact very fast cars compared to their contemporaries and they tempted drivers into turn complexes at an entry speed that was too high. Once committed, drivers tended to run out of talent and road at the same time. The final result was the same as it would have been with a great many cars because it was a trait of the early independent suspension systems. I must have had two dozen different Spitfires and TR-4's spin in front of me learning that lesson. (Enough to learn how to judge which side to pass them on as they spun to avoid being hit.) If anything, Porsches seemed more resistent to that behavior because their suspension was more sophisticated than the simple swing axle.
The difference was that not many cars seduced you so easily as a Porsche to overdrive your skill level. And once you did, the rear engine certainly rubbed it in. But mostly the engine position made an easy scapegoat that hurt less than admitting you broke your racer being stupid.
And lifting off the throttle in the corner was the last stupid act before the crunch. Going into the corner that fast was the first one of course.
Gary
#48
Nordschleife Master
And not lifting is a matter of degree. I'm convinced that many people still think that when we say 'not lift' means flooring the throttle. People grow up to sports cars but have no sense of mass movement and balance.
#49
Lift throttle oversteer is extraordinarily difficult to even intentionally provoke in a modern Porsche. With electronic aids off, students and instructors at PSDS found it nearly impossible to purposely make it occur on a dry skid pad. During my turn, in frustration, I cheated and made it happen by using a Scandinavian flick preceeding the throttle lift...lol.
This was a specific exercise we did to help inform those who still belived all the BS from 30 years ago about "killer Porsches". Benign, progressive, forgiving and predictable are my descriptive words.
And as usual I fully agree with our two resident wise men (one verbose one succinct ), simsgw and ADias above. If you do something truly boneheaded at the wrong time, you will have an agricultural experience regardless (or in spite) of what car you are driving.
This was a specific exercise we did to help inform those who still belived all the BS from 30 years ago about "killer Porsches". Benign, progressive, forgiving and predictable are my descriptive words.
And as usual I fully agree with our two resident wise men (one verbose one succinct ), simsgw and ADias above. If you do something truly boneheaded at the wrong time, you will have an agricultural experience regardless (or in spite) of what car you are driving.
#50
The point I was trying to make is tha Porsche does not always have the perfect or fully tested solution when I refered to some problems with engine and clutch designs, etc. The other point that is being elaborated on here is the fact that Porsches ( yes, I mean the 1970s, in particular) were tail heavy and had semi-trailing arm rear suspensions. This, made them particularly vulnerable to tailing throttle oversteer. Lifting the throttle would slightly turn the rear wheels outward and the trouble became serious very quickly if you were "at the edge". This instability was used to advantage in higher HP 911 racers if the driver was very good they could steer the car very significantly with the throttle. There were not too many rear engined cars with semi-training arm suspenions. This is well known Porsche trait and Porsche addressed much of that with 993 design changes. Today, stability control helps many designs regardless of the brand. The DI fuel systems will have their issues whether it is Porsche, BMW, Audi, VW or....because these systems are designed and supplied by the same fuel system companies.
#51
Race Director
I think we are, Postal. The ones who actually have a DFI car that is. All this discussion of "bound to be a problem" seems to come from people who don't have a 997.2. None of us with one have reported a problem, and we don't expect one. For about the same reasons you cite. Our dealers have also reported knowing nothing of any problems with a 911 DFI engine, so we appreciate your confirmation. But I don't expect it to change the wailing from people who have 997.1's or earlier models and are convincing themselves we buyers of the 997.2 at historic discounts are going to be burned. Somehow. If this doesn't work out, they believe it surely will be oil consumption. (ADias and I aren't bitching. I don't remember whether any other DFI owner has complained of that.) If that doesn't show up as worse than any other boxer engine, I'm sure they'll start to tell us our upholstery is bound to rot early.
I'm just enjoying the hell out of my 997.2, and sleeping just fine despite all the jabber about my grapes in the garage souring overnight.
Gary
I'm just enjoying the hell out of my 997.2, and sleeping just fine despite all the jabber about my grapes in the garage souring overnight.
Gary
One comment by a tech was in Europe Porches are bought to be driven, while in the USA they are bought to be stored. The lack of regular use and coupled with the somewhat different driving conditions we in many areas of the USA encounter help contribute to problems Porsches don't seem to have in other regions of the world.
Now some have made the point -- and it is a good point -- that it is up to Porsche to design and build engines that can tolerate the usage they receive in regions of the world that result in a less than ideal type of driving on these cars.
Since the USA is one of if not the biggest market for Porsches (and BMWs, Mercedes, etc) these car makers should take into account in their engine designs and servicing intervals, etc., the special and dare I say less than ideal types of usage these cars encounter here.
There was mention -- I have not seen any confirmation though -- of the factory developing a DFI engine deposit remover system along the lines of having some machine feed the engine's intake system a fluid in vapor form that helps remove deposits while the engine idles. Afterwards the engine oil/filter is changed.
I'll end with the comment I have no feelings of sour grapes concerning the newer cars. I seriously considered buying a new Porsche (Cayman S) with a DFI engine, and PDK, but came upon a nice 03 Turbo and bought that instead.
My next Porsche will almost certainly be one with a DFI engine and a PDK transmission and if possible PCCB brakes too, probably in the form of a Cayman S.
My belief is that if I can manage -- and I have -- to get over 240K miles out of my 02 Boxster's original engine with no engine troubles I think I can manage to get satisfactory service and engine life out of a DFI engine in a newer Porsche. In fact, as much as I like still driving my Boxster and my 03 Turbo, I'm looking forward to it.
Sincerely,
Macster.
#52
Drifting
God, it rains continuously here in the Pacific NW...
Not...!
But the idea keeps the Californians away.
All Porsche 911's have an absolutely horrible tendancy for lift-throttle overstear...!!
Pass it on.
Not...!
But the idea keeps the Californians away.
All Porsche 911's have an absolutely horrible tendancy for lift-throttle overstear...!!
Pass it on.
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Gary
#54
Still looking forward to meeting you two at a track event. Spring Mtn is close to you Gary, yes? May 15/16 SpeedVentures? Yeah baby!
#55
I just got an '05C2 a month ago and its been in the shop 3 times chasing the CEL. Replaced all coils, cleaned the injectors and said they DECARBONIZED the back of the valves! 50,800 miles. CPO. Light came on again today and they just told me to drive it... they'll come get it later?
#56
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Maybe I could talk her into it with a rest stop en route. Is there a reasonable hotel near the track? We've never been there before. Uh... I see it's near Pahrump, so let me re-phrase that. Is there a reasonable motel nearby? Or should I just plan it for the night at Las Vegas?
Gary