Planet 9

Nitro8472 · #41 04-28-2009, 03:46 PM

Originally Posted by markstudy

Small volume car manufactures, have always used their costumers as part of the quality and testing phase.

Buying from a specialty company is one part charm, two parts...pain in the azz

Porsche might be 10 times bigger than Ferrari, and 15 times bigger than Lambo.....but they are still very small, so we become the testing dummies

But that surely will leave them with a lot of unsatisfied customers, I dont think this is good for business!

NorminHouston · #42 04-28-2009, 03:56 PM

Originally Posted by Nitro8472

But that surely will leave them with a lot of unsatisfied customers, I dont think this is good for business!

I don't think Porsche gives a damn. Otherwise they would have helped owners more with the RMS and IMS issues.

markstudy · #43 04-28-2009, 03:58 PM

Originally Posted by Nitro8472

But that surely will leave them with a lot of unsatisfied customers, I dont think this is good for business!

That's why most car companies are huge!

But if you want something special, you have to be willing to put-up with the rough edges....sort-to-speak

Ferrari is 10 times smaller and has lots of newly rich businessmen that buy their 1st Ferrari and are deeply disappointed when the car is in the shop multiple times in the 1st year of ownership. Compared to the long time Ferrari owners who know about these quality issues and consider it just part of having something so rare and limited. The true Ferrari fan deals with it. Many new costumers never come back...sighting the exotic car experience as disappointing.

Porsche seems right in the middle... not as bad as Ferrari, but its not going to be Lexus quality either. But you have to give Porsche lots of credit for getting a lot closer to Lexus with such small volumes. Porsche is impressive for what they are trying to do.... its just the small production runs work against them when it comes to spotting quality issues.

I wonder if it comes from rushing new technology into production? DFI, new electronics, and a new engine block is a lot to add in one model year.

It seems..... new car models are being squeezed into a tighter 3 year life cycle, instead of the more traditional 5 year model run?

DFI

Direct Fuel Injection (DFI), is a new technology that Porsche states can cut fuel consumption by up to 15 percent, while increasing power by up to 13 percent. DFI cuts emissions by warming up the catalytic converter more quickly, and ensures a sharper throttle response. Better for your right foot - and the planet, then.

DFI allows much more precise measurement of fuel supply and injection at pressures up to 120 bar; it has numerous combustion modes, with different cycles for cold-starting, low-speed driving and performance driving.

As the name suggests, DFI injects fuel directly into the individual combustion chambers, instead of the intake manifold. The injector valves have an electromagnetic mechanism that controls each injection with astonishing precision, while a high-pressure pump provides the necessary pressure—up to 1,740 psi—to accompany the rapid fire of the fuel injection.

Precise geometry of the injector’s position and its spray pattern is a key factor in helping to improve power, torque and emissions of the engines. The specific placement of the fuel as it enters each chamber creates a swirl that improves the air/fuel mixture, and therefore the overall combustion process.

At engine speeds up to 3500 rpm, a double-injection process is used. In this mode, the required fuel volume is delivered in two successive injections per working stroke. The resulting benefits include faster catalyst warm-up and increased torque in the upper load range.

By forming the air/fuel mix directly in the combustion chamber, DFI contributes to engine cooling. As a result, it is possible to increase the compression ratio and with it the power and efficiency of the engine.

The direct injection process is continuously adjusted. The engine management system reads changes to throttle inputs and performance requirements and, as you drive, the air/fuel mix is monitored and adapted as required. Oxygen sensor circuits within the exhaust system provide accurate emissions control.

DaveCS2009 · #44 04-28-2009, 05:35 PM

I've been a regular on this site ever since I put my deposit down for a 2009 build slot and look forward to informative posts like this. My car is due any day now (dealer keeps telling me on vessel, but once its in San Diego, just a short drive up the coast). One thing I've been on the fence about is to buy outright, large down and finance, or lease. I always had a small concern about buying the new Cayman with the new DFI engine (I ordered an S), as well as long term maintenance costs, high depreciation, etc. This latest string has me leaning towards lease. I work from home, so mileage isn't an issue, no plans to track the car, trying to avoid a large payout in cash (accountant recommendation given current climate) and wouldn't mind driving the heck out of the car and then handing it over to Porsche at lease end and let them deal with the maintenance issues (if any). Does this logic make sense? Am I overreacting to this post? Is the build up problem or previously mentioned soot issue catastrophic or just a nuisance?

DFI

Direct Fuel Injection (DFI), is a new technology that Porsche states can cut fuel consumption by up to 15 percent, while increasing power by up to 13 percent. DFI cuts emissions by warming up the catalytic converter more quickly, and ensures a sharper throttle response. Better for your right foot - and the planet, then.

DFI allows much more precise measurement of fuel supply and injection at pressures up to 120 bar; it has numerous combustion modes, with different cycles for cold-starting, low-speed driving and performance driving.

As the name suggests, DFI injects fuel directly into the individual combustion chambers, instead of the intake manifold. The injector valves have an electromagnetic mechanism that controls each injection with astonishing precision, while a high-pressure pump provides the necessary pressure—up to 1,740 psi—to accompany the rapid fire of the fuel injection.

Precise geometry of the injector’s position and its spray pattern is a key factor in helping to improve power, torque and emissions of the engines. The specific placement of the fuel as it enters each chamber creates a swirl that improves the air/fuel mixture, and therefore the overall combustion process.

At engine speeds up to 3500 rpm, a double-injection process is used. In this mode, the required fuel volume is delivered in two successive injections per working stroke. The resulting benefits include faster catalyst warm-up and increased torque in the upper load range.

By forming the air/fuel mix directly in the combustion chamber, DFI contributes to engine cooling. As a result, it is possible to increase the compression ratio and with it the power and efficiency of the engine.

The direct injection process is continuously adjusted. The engine management system reads changes to throttle inputs and performance requirements and, as you drive, the air/fuel mix is monitored and adapted as required. Oxygen sensor circuits within the exhaust system provide accurate emissions control.

Tomasz · #45 04-29-2009, 05:26 AM

Originally Posted by DaveCS2009

I've been a regular on this site ever since I put my deposit down for a 2009 build slot and look forward to informative posts like this. My car is due any day now (dealer keeps telling me on vessel, but once its in San Diego, just a short drive up the coast). One thing I've been on the fence about is to buy outright, large down and finance, or lease. I always had a small concern about buying the new Cayman with the new DFI engine (I ordered an S), as well as long term maintenance costs, high depreciation, etc. This latest string has me leaning towards lease. I work from home, so mileage isn't an issue, no plans to track the car, trying to avoid a large payout in cash (accountant recommendation given current climate) and wouldn't mind driving the heck out of the car and then handing it over to Porsche at lease end and let them deal with the maintenance issues (if any). Does this logic make sense? Am I overreacting to this post? Is the build up problem or previously mentioned soot issue catastrophic or just a nuisance?

Almost makes sense. Lease it. Take good care of it. If it takes good care of you , buy out the lease and keep it. The jury is out on the soot issue...

JCE · #46 04-29-2009, 12:01 PM

Maybe a stupid question.....what other manufacturer's have DFI engines, and why isn't this an issue with them? Or is it?

DFI

Direct Fuel Injection (DFI), is a new technology that Porsche states can cut fuel consumption by up to 15 percent, while increasing power by up to 13 percent. DFI cuts emissions by warming up the catalytic converter more quickly, and ensures a sharper throttle response. Better for your right foot - and the planet, then.

DFI allows much more precise measurement of fuel supply and injection at pressures up to 120 bar; it has numerous combustion modes, with different cycles for cold-starting, low-speed driving and performance driving.

As the name suggests, DFI injects fuel directly into the individual combustion chambers, instead of the intake manifold. The injector valves have an electromagnetic mechanism that controls each injection with astonishing precision, while a high-pressure pump provides the necessary pressure—up to 1,740 psi—to accompany the rapid fire of the fuel injection.

Precise geometry of the injector’s position and its spray pattern is a key factor in helping to improve power, torque and emissions of the engines. The specific placement of the fuel as it enters each chamber creates a swirl that improves the air/fuel mixture, and therefore the overall combustion process.

At engine speeds up to 3500 rpm, a double-injection process is used. In this mode, the required fuel volume is delivered in two successive injections per working stroke. The resulting benefits include faster catalyst warm-up and increased torque in the upper load range.

By forming the air/fuel mix directly in the combustion chamber, DFI contributes to engine cooling. As a result, it is possible to increase the compression ratio and with it the power and efficiency of the engine.

The direct injection process is continuously adjusted. The engine management system reads changes to throttle inputs and performance requirements and, as you drive, the air/fuel mix is monitored and adapted as required. Oxygen sensor circuits within the exhaust system provide accurate emissions control.

Gator Bite · #47 04-29-2009, 01:20 PM

Originally Posted by echoboy

Rockster, nice summary! thanks

+3....!

Originally Posted by Rockster

The problem is exacerbated by mainly the way we in USA drive our vehicles. Lots of idling and low rpm usage. Most engines spend their time operating at 30% of throttle or less and under these conditions it is more likely air flow in the combustion chamber will be backwards and purposely so. Over time build up will occur.

>>>trim<<<

3) Use higher engine rpms. Granted this one's tough cause we are all seeking to use lower engine rpms to mainly save fuel. One doesn't have to run engine to red line every shift but any bit of extra engine rpms helps.

You know, this has been true long before DFI. Back in the carburetter days low RPM use of these engines would foul spark plugs and carbon up the combustion chamber.

So many times I meet owners that brag that they've never redlined their car, or that they don't rev their engine high because they think it hurts it. In their mind they think they are preserving their car. In my mind, their abusing it. If I were looking for a used Cayman and the owner bragged about this, I'd probably walk away from it. In my experience, when you buy a babied car and then drive it right, it will break.

Originally Posted by madcow

Crappy us gas.

This has nothing to do with the gas.

Originally Posted by Lucky

I was thinking of calling the dealership on Monday and see what they have to say about all of this. If they will cover it then I will not worry about it. Want to be sure I do not drop 80k on a car that is going to have issues with DFI. Thanks for your opinion.

Let me save you the phone call. They will say, "What...? Never heard of it.... No, that can't be...."

In all seriousness, this is probably a very rare situation, and the cars do carry a warranty that will cover this.

Originally Posted by Rockster

I just normally hold off buying a new model of any car. 'course a '10 is the second year of the new engine/transmission.

Anyway, I prefer to buy the last example of a model before a changeover. Generally these are the best sorted cars and have a couple to 4 or more years of fixes applied.

Me too. I had a 1986 944 Turbo. There were a number of 'issues' that were improved upon in the 1987 model. I avoided the 2006 Cayman for this reason. Cars are so complex today that it's nearly impossible to truly reproduce what cars will go through when they reach the real world.

Originally Posted by Tomasz

Lets not exaggerate this. I am sure Porsche will come up with a fix. I do believe its as simple as software. Best part, if you track and drive your hard - it runs better!

Agreed. Don't panic.

Originally Posted by DaveCS2009

I work from home, so mileage isn't an issue, no plans to track the car, trying to avoid a large payout in cash (accountant recommendation given current climate) and wouldn't mind driving the heck out of the car and then handing it over to Porsche at lease end and let them deal with the maintenance issues (if any). Does this logic make sense? Am I overreacting to this post? Is the build up problem or previously mentioned soot issue catastrophic or just a nuisance?

Not a bad logic, but it may be a slight over-reaction. Leasing right now is not a bad idea because residuals are tanking beyond calculated expectations.

Originally Posted by JCE

Maybe a stupid question.....what other manufacturer's have DFI engines, and why isn't this an issue with them? Or is it?

I suspect this is a more wide spread problem affecting many DFI engines. Gasoline DFI is very new and there are likely to be gremlins. The technology is great and worth any bumps in the road.

DFI

Direct Fuel Injection (DFI), is a new technology that Porsche states can cut fuel consumption by up to 15 percent, while increasing power by up to 13 percent. DFI cuts emissions by warming up the catalytic converter more quickly, and ensures a sharper throttle response. Better for your right foot - and the planet, then.

DFI allows much more precise measurement of fuel supply and injection at pressures up to 120 bar; it has numerous combustion modes, with different cycles for cold-starting, low-speed driving and performance driving.

As the name suggests, DFI injects fuel directly into the individual combustion chambers, instead of the intake manifold. The injector valves have an electromagnetic mechanism that controls each injection with astonishing precision, while a high-pressure pump provides the necessary pressure—up to 1,740 psi—to accompany the rapid fire of the fuel injection.

Precise geometry of the injector’s position and its spray pattern is a key factor in helping to improve power, torque and emissions of the engines. The specific placement of the fuel as it enters each chamber creates a swirl that improves the air/fuel mixture, and therefore the overall combustion process.

At engine speeds up to 3500 rpm, a double-injection process is used. In this mode, the required fuel volume is delivered in two successive injections per working stroke. The resulting benefits include faster catalyst warm-up and increased torque in the upper load range.

By forming the air/fuel mix directly in the combustion chamber, DFI contributes to engine cooling. As a result, it is possible to increase the compression ratio and with it the power and efficiency of the engine.

The direct injection process is continuously adjusted. The engine management system reads changes to throttle inputs and performance requirements and, as you drive, the air/fuel mix is monitored and adapted as required. Oxygen sensor circuits within the exhaust system provide accurate emissions control.

Lucky · #48 04-29-2009, 01:43 PM

Originally Posted by Gator Bite

+3....!

You know, this has been true long before DFI. Back in the carburetter days low RPM use of these engines would foul spark plugs and carbon up the combustion chamber.

So many times I meet owners that brag that they've never redlined their car, or that they don't rev their engine high because they think it hurts it. In their mind they think they are preserving their car. In my mind, their abusing it. If I were looking for a used Cayman and the owner bragged about this, I'd probably walk away from it. In my experience, when you buy a babied car and then drive it right, it will break.

This has nothing to do with the gas.

Let me save you the phone call. They will say, "What...? Never heard of it.... No, that can't be...."

In all seriousness, this is probably a very rare situation, and the cars do carry a warranty that will cover this.

Me too. I had a 1986 944 Turbo. There were a number of 'issues' that were improved upon in the 1987 model. I avoided the 2006 Cayman for this reason. Cars are so complex today that it's nearly impossible to truly reproduce what cars will go through when they reach the real world.

Agreed. Don't panic.

Not a bad logic, but it may be a slight over-reaction. Leasing right now is not a bad idea because residuals are tanking beyond calculated expectations.

I suspect this is a more wide spread problem affecting many DFI engines. Gasoline DFI is very new and there are likely to be gremlins. The technology is great and worth any bumps in the road.

True on that phone call. They said they have not seen any problems. I do drive my sports cars hard like they are meant to be in my opinion. Why have that power and not use it...
I would think that if there truly is a problem then Porsche will get on it. Maybe the 2010 will already have a fix.

DFI

Direct Fuel Injection (DFI), is a new technology that Porsche states can cut fuel consumption by up to 15 percent, while increasing power by up to 13 percent. DFI cuts emissions by warming up the catalytic converter more quickly, and ensures a sharper throttle response. Better for your right foot - and the planet, then.

DFI allows much more precise measurement of fuel supply and injection at pressures up to 120 bar; it has numerous combustion modes, with different cycles for cold-starting, low-speed driving and performance driving.

As the name suggests, DFI injects fuel directly into the individual combustion chambers, instead of the intake manifold. The injector valves have an electromagnetic mechanism that controls each injection with astonishing precision, while a high-pressure pump provides the necessary pressure—up to 1,740 psi—to accompany the rapid fire of the fuel injection.

Precise geometry of the injector’s position and its spray pattern is a key factor in helping to improve power, torque and emissions of the engines. The specific placement of the fuel as it enters each chamber creates a swirl that improves the air/fuel mixture, and therefore the overall combustion process.

At engine speeds up to 3500 rpm, a double-injection process is used. In this mode, the required fuel volume is delivered in two successive injections per working stroke. The resulting benefits include faster catalyst warm-up and increased torque in the upper load range.

By forming the air/fuel mix directly in the combustion chamber, DFI contributes to engine cooling. As a result, it is possible to increase the compression ratio and with it the power and efficiency of the engine.

The direct injection process is continuously adjusted. The engine management system reads changes to throttle inputs and performance requirements and, as you drive, the air/fuel mix is monitored and adapted as required. Oxygen sensor circuits within the exhaust system provide accurate emissions control.

Nitro8472 · #49 04-29-2009, 05:43 PM

Originally Posted by markstudy

That's why most car companies are huge!

But if you want something special, you have to be willing to put-up with the rough edges....sort-to-speak

Ferrari is 10 times smaller and has lots of newly rich businessmen that buy their 1st Ferrari and are deeply disappointed when the car is in the shop multiple times in the 1st year of ownership. Compared to the long time Ferrari owners who know about these quality issues and consider it just part of having something so rare and limited. The true Ferrari fan deals with it. Many new costumers never come back...sighting the exotic car experience as disappointing.

Porsche seems right in the middle... not as bad as Ferrari, but its not going to be Lexus quality either. But you have to give Porsche lots of credit for getting a lot closer to Lexus with such small volumes. Porsche is impressive for what they are trying to do.... its just the small production runs work against them when it comes to spotting quality issues.

That does make sense, but I'm sure it WILL make some customers "never come back"

Originally Posted by NorminHouston

I don't think Porsche gives a damn. Otherwise they would have helped owners more with the RMS and IMS issues.

As much as I disagree about Porsche not giving a damn, I cant help but wonder why these and the infamous trunk clunk (I've never experienced it, I have a Boxster) are not fixed yet!

**Blitzkrieg** · #50 04-29-2009, 05:49 PM

Originally Posted by Gator Bite

So many times I meet owners that brag that they've never redlined their car, or that they don't rev their engine high because they think it hurts it. In their mind they think they are preserving their car. In my mind, their abusing it. If I were looking for a used Cayman and the owner bragged about this, I'd probably walk away from it. In my experience, when you buy a babied car and then drive it right, it will break.

It's true, best thing you can do to keep a car's components healthy is to drive it

.

I'm not too concerned about potential DFI issues, Porsche seems to be good about owning up to their faults and fixing them under warranty.

DaveCS2009, have to agree on the lease to buy, its win win. Either get to turn in the car if it has issues or keep it if hassle free. I'm in the lease to buy boat myself and after seeing other threads showing a 41k residual reduced to 28,5k at lease end I hope to be as lucky. Not sure what the negotiated value was when the lease started, but an additional 12,5k off

is nothing to sneeze at.

DFI

Direct Fuel Injection (DFI), is a new technology that Porsche states can cut fuel consumption by up to 15 percent, while increasing power by up to 13 percent. DFI cuts emissions by warming up the catalytic converter more quickly, and ensures a sharper throttle response. Better for your right foot - and the planet, then.

DFI allows much more precise measurement of fuel supply and injection at pressures up to 120 bar; it has numerous combustion modes, with different cycles for cold-starting, low-speed driving and performance driving.

As the name suggests, DFI injects fuel directly into the individual combustion chambers, instead of the intake manifold. The injector valves have an electromagnetic mechanism that controls each injection with astonishing precision, while a high-pressure pump provides the necessary pressure—up to 1,740 psi—to accompany the rapid fire of the fuel injection.

Precise geometry of the injector’s position and its spray pattern is a key factor in helping to improve power, torque and emissions of the engines. The specific placement of the fuel as it enters each chamber creates a swirl that improves the air/fuel mixture, and therefore the overall combustion process.

At engine speeds up to 3500 rpm, a double-injection process is used. In this mode, the required fuel volume is delivered in two successive injections per working stroke. The resulting benefits include faster catalyst warm-up and increased torque in the upper load range.

By forming the air/fuel mix directly in the combustion chamber, DFI contributes to engine cooling. As a result, it is possible to increase the compression ratio and with it the power and efficiency of the engine.

The direct injection process is continuously adjusted. The engine management system reads changes to throttle inputs and performance requirements and, as you drive, the air/fuel mix is monitored and adapted as required. Oxygen sensor circuits within the exhaust system provide accurate emissions control.

BillK · #51 04-30-2009, 02:00 AM

Originally Posted by Gator Bite

So many times I meet owners that brag that they've never redlined their car, or that they don't rev their engine high because they think it hurts it. In their mind they think they are preserving their car. In my mind, their abusing it. If I were looking for a used Cayman and the owner bragged about this, I'd probably walk away from it. In my experience, when you buy a babied car and then drive it right, it will break..

Guess I'm an abuser then - not only has my CS never seen redline in its year of ownership, I can count the number of times it's seen 4K RPM (around six or seven, always on on-ramps.)

Worse, I usually shift 1-3-6 when driving, keeping the RPMs well below 4K.

Note this isn't far off of how a Tip normally shifts, either.

ELP_JC · #52 04-30-2009, 04:29 AM

Ask BMW if they don't have DFI issues. Their problem is loss of pressure, and loss of performance without ECU throwing a CEL. Also burned fuel pumps. You're talking about 1,200 psi, vs around 60 for 'normal' EFI.

I'm not jumping on that band wagon in the next few years, especially on a Porsche, with no dealers around. But don't enjoy having to fix a new car either. Later.

DFI

Direct Fuel Injection (DFI), is a new technology that Porsche states can cut fuel consumption by up to 15 percent, while increasing power by up to 13 percent. DFI cuts emissions by warming up the catalytic converter more quickly, and ensures a sharper throttle response. Better for your right foot - and the planet, then.

DFI allows much more precise measurement of fuel supply and injection at pressures up to 120 bar; it has numerous combustion modes, with different cycles for cold-starting, low-speed driving and performance driving.

As the name suggests, DFI injects fuel directly into the individual combustion chambers, instead of the intake manifold. The injector valves have an electromagnetic mechanism that controls each injection with astonishing precision, while a high-pressure pump provides the necessary pressure—up to 1,740 psi—to accompany the rapid fire of the fuel injection.

Precise geometry of the injector’s position and its spray pattern is a key factor in helping to improve power, torque and emissions of the engines. The specific placement of the fuel as it enters each chamber creates a swirl that improves the air/fuel mixture, and therefore the overall combustion process.

At engine speeds up to 3500 rpm, a double-injection process is used. In this mode, the required fuel volume is delivered in two successive injections per working stroke. The resulting benefits include faster catalyst warm-up and increased torque in the upper load range.

By forming the air/fuel mix directly in the combustion chamber, DFI contributes to engine cooling. As a result, it is possible to increase the compression ratio and with it the power and efficiency of the engine.

The direct injection process is continuously adjusted. The engine management system reads changes to throttle inputs and performance requirements and, as you drive, the air/fuel mix is monitored and adapted as required. Oxygen sensor circuits within the exhaust system provide accurate emissions control.

wilson4tw · #53 04-30-2009, 04:31 AM

I am very glad to see this thread is still being so constructive and viewed from every possible angle. I will tend to agree with the "drive it like you stole it" crowd to a degree. Driving these cars like a baby doesn't really serve much of a purpose from my perspective. They are meant to be driven and enjoyed to the fullest.
I think almost all of you are wise enough to run it thru the gears while not being abusive. There are just too many of you tracking your cars(or a DE) and having minimal problems currently.
If any of you are from the older racing scene, we were always taught city driving from light to light is hard on an engine compared to highway miles, i.e. giving enough time to burn the carbon off of pistons etc. The only fault of this is no fuel flowing over the valves. Or maybe there can be a benefit of high velocity still......this might not be a bad idea if your car gives a puff of smoke from burning oil after being driven hard either. I have poured tranny fluid down a carb to unstick valves before.

I think one of the greatest things we should remember is what kind of car we bought and who made it. There is no way I would take a stock chevy and track it expecting it to hold up very well, and I have raced chevys all my life. there are reasons porsche has the reputation they have. RACING !!!! and these cars might be a little tamer, but they are meant to be driven harder than the average car and still maintain reliability.
If your lucky to live in florida like me( from Texas), they have the strangest entrance ramps to get on i-75 in most places. This seems like a good place to wind her up a bit, then merging in with traffic. ( remember oldies drive in the center lane tho hehe) Only time will tell. and judos to the chap who got 217k out of his boxter, I had no idea they would last that long.

ul2fly · #54 04-30-2009, 04:32 AM

Originally Posted by BillK

Guess I'm an abuser then - not only has my CS never seen redline in its year of ownership, I can count the number of times it's seen 4K RPM (around six or seven, always on on-ramps.)

Worse, I usually shift 1-3-6 when driving, keeping the RPMs well below 4K.

Note this isn't far off of how a Tip normally shifts, either.

You are

I hope!

ul2fly · #55 04-30-2009, 04:38 AM

I knew this would come up again.
http://www.planetporsche.net/cayman-...drawbacks.html

BillK · #56 04-30-2009, 02:48 PM

Originally Posted by ul2fly

You are

I hope!

Why would I be kidding?

I usually shift around 3200 RPM from 1 -> 3, and as soon as I get to speed as long as that speed isn't one that will lug in 6th, into 6th.

On on-ramps, I shift up around 3800 RPM.

ul2fly · #57 04-30-2009, 05:16 PM

Originally Posted by BillK

Why would I be kidding?

I usually shift around 3200 RPM from 1 -> 3, and as soon as I get to speed as long as that speed isn't one that will lug in 6th, into 6th.

On on-ramps, I shift up around 3800 RPM.

Hey its is your car drive it like you want, but please note that the torque generated @ 3200 is less than @ 2500. Now don't get me wrong! 1st to 2nd shifts @ 6500 can be a wild ride, and most of us don't rap out 1st gear that far. It is however perfectly OK to take the car up to 7000 even if just on the ramp to the hwy.

On a gas saving note, if that is the reason. I once was on a trip and reset the mpg meter while cooking @ 70 mph, and found I was getting about 28 mpg. I then did the same test BUT droped a gear down, and be damed if it wasn't 27 mpg, moral of this story rpms dont allways = fuel flow.

Ok now when and if you do decide to take the car up to 7k rpm, make sure no cars are behind you, because there will be a cloud of black soot, and we don't want anyone pointing at a Cayman like that.

AlexMcNabb · #58 04-30-2009, 08:07 PM

I remember stories of the old FIATs misbehaving, and being taken to a mechanic who then simply drove the snot out of it for a few miles, fixing the "problem". Even the BMW acolytes will tell you those cars are not designed for idling in traffic. (Honda is a better choice for that) My perspective is that Euros are better engineered for high speed interstate driving, and blasting around back roads. I definitely wind out mine very hard when I'm in Virginia, considerably less so down here in NC where the traffic density isn't conducive to "spirited driving". Lugging around at low RPMs is something I reserve for Corvettes and other V8 torque monsters.

Lucky · #59 04-30-2009, 08:35 PM

Originally Posted by AlexMcNabb

I remember stories of the old FIATs misbehaving, and being taken to a mechanic who then simply drove the snot out of it for a few miles, fixing the "problem". Even the BMW acolytes will tell you those cars are not designed for idling in traffic. (Honda is a better choice for that) My perspective is that Euros are better engineered for high speed interstate driving, and blasting around back roads. I definitely wind out mine very hard when I'm in Virginia, considerably less so down here in NC where the traffic density isn't conducive to "spirited driving". Lugging around at low RPMs is something I reserve for Corvettes and other V8 torque monsters.

The more I read and talk to people who own a Porsche they all say the same thing. Drive the car like it is meant to be driven and enjoy it. I drive a BMW now and it is DFI and has no problems at all. Have 20k miles on it and have only changed the oil twice. Plan to keep it when my 2010 CS is delivered and drive them both as hard as possible. Here in Atlanta I have driven at 90 mph and she has plenty more to go. Do not track my cars. Lots of twisty roads to play on and plenty of interstate to open up on.

DFI

Direct Fuel Injection (DFI), is a new technology that Porsche states can cut fuel consumption by up to 15 percent, while increasing power by up to 13 percent. DFI cuts emissions by warming up the catalytic converter more quickly, and ensures a sharper throttle response. Better for your right foot - and the planet, then.

DFI allows much more precise measurement of fuel supply and injection at pressures up to 120 bar; it has numerous combustion modes, with different cycles for cold-starting, low-speed driving and performance driving.

As the name suggests, DFI injects fuel directly into the individual combustion chambers, instead of the intake manifold. The injector valves have an electromagnetic mechanism that controls each injection with astonishing precision, while a high-pressure pump provides the necessary pressure—up to 1,740 psi—to accompany the rapid fire of the fuel injection.

Precise geometry of the injector’s position and its spray pattern is a key factor in helping to improve power, torque and emissions of the engines. The specific placement of the fuel as it enters each chamber creates a swirl that improves the air/fuel mixture, and therefore the overall combustion process.

At engine speeds up to 3500 rpm, a double-injection process is used. In this mode, the required fuel volume is delivered in two successive injections per working stroke. The resulting benefits include faster catalyst warm-up and increased torque in the upper load range.

By forming the air/fuel mix directly in the combustion chamber, DFI contributes to engine cooling. As a result, it is possible to increase the compression ratio and with it the power and efficiency of the engine.

The direct injection process is continuously adjusted. The engine management system reads changes to throttle inputs and performance requirements and, as you drive, the air/fuel mix is monitored and adapted as required. Oxygen sensor circuits within the exhaust system provide accurate emissions control.

**K-Man S** · #60 04-30-2009, 08:37 PM

You guys know there is an Audi service campaign where they are walnut-chip blasting the valves right?

Talk about a "nutty" solution!