wwest

I have a 2009 Carrera S with PDK with 4000 miles on it......I recently took a 1400 mile trip and averaged 72 mph and got 29.1 mpg while driving in regular mode most of the time......In town I get 19-20 and drive in the Sport mode almost all the time.

Sounds right.

Our '01 C4 averaged 25MPG throughout europe, ~1500 miles, much of that on the Autobahn not going slow.

Once in a lifetime event so I wasn't paying much attention to break-in procedures.

I have an '09 C4S and when I have the AC on fully automatic mode it blows cold air from the expected vents on the dash as well as from the defroster vents regardless of the cabin temperature. I think it should not blow cool air from the defroster vents except when I select "Defrost." Is this normal?

Thanks.

MWS

"...Is this normal.."

According to Porsche, yes. According to VW (and the ROW) no, NO..!!

Maybe now that VW "owns" Porsche this will finally get fixed in the same way that VW fixed their version of the Cayenne, firmware revision.

In the meantime the best procedure to use is turn the defrost/defog/vents "on" then back off. On my '01 C4 this procedure works.

This design flaw can prove to be dangerous, especially in your part of the country.

In July of '01 I was approaching Birmingham Alabama in the early evening just after dusk after a HOT day. Sporadic rain showers late in the afternoon early evening along the way. I was finding it a little hard to see the road ahead, bi-xenon projectors on, and finally came to the realization that condensation on the OUTSIDE of the windshield was getting denser and denser as I drove along. WHAT..??

Quick swipe of the wipers cleared up the windshield.

I had noticed a climate control anomally, had to reajust the temperature setting from time to time, during our drive in Europe. Mentioned it to the factory rep (shrug..) when we turned it in. Picked it up at POE at noon that July day. It wasn't until I got back home that I took time to figure out what was wrong.

On my '01 it only begins to route airflow from the defrost/defog/demist ducts once the cabin temperature is cooled down to within a few degrees of the temperature setpoint. I suspect it is designed this way so as to not discomfort the driver and passenger with too much COLD airflow directly to the face an upper body. We might like to set directly in front of a window air condition to initially cool down coming inside on a HOT day but once our comfort level is reached we move away to enjoy the room's "general" coolness.

Oh, you can improve the functionality of your A/C system fairly dramatically by installing a shut-off valve in the hose to the heater core. Shut the flow off in the summertime and the A/C compressor duty cycle will fall dramatically as will fuel consumption, abet not so dramatically.

sounds like it is time to replace shifter bushings

At least the coupler bushings under the cover right in the "tunnel" at the center point of the four seats.

Radiator Fan and Engine Compartment Fan Switch Mod

The 3.4 996 runs extremely hot when driving around town in temperatures higher than 75 degrees. This mod is a way to reduce coolant temps back to a safer level, helping to reduce oil temps and improving performance.

Or....(***)

You can turn the A/C temperature down to "freezing" and then manually adjust the blower speed to attain the desired cabin comfort level. The reheat/remix blend door will be fully closed to reheat, the compressor will run a LOT less often AND the heat load on th engine coolant radiators will be substantially reduced.

If the lowest blower is too cool then I switch the system to combined, floor and dash A/C airflow.

You can also improve the A/C efficiency more simply by installing a manual shut-off valve in the coolant hose to the heater core. Not even any radiant heating of the system airflow nor your right foot/leg, that way.

Improve FE to boot.

NEVER allow the system to automatically switch to windshield air outflow when using this technique. In point of fact it is wise to ALWAYS cycle the windshield airflow ducts open then OFF regardless to avoid inadvertent instances of outside windshield fogging, sometimes at the WORSE possible moment.

The mod consists of installing a switch that will allow you to turn on the high speed radiator fans at any time, while maintaining the automatic operation of the fans. We do the same for the engine compartment fan.

Radiator Fans

Connect a wire to the ground (Pin #85) of the 2 high speed fan relays located on the relay carrier located in the driver’s side foot well. The relays are #20 and #22. Feed this wire to where your switch will be located. Connect the wire to one side of the switch. Connect another wire from the other contact on the switch and then connect the other end of this wire to a chassis ground point.

With key on, this switch will now immediately turn on both radiator fans providing maximum cooling. When you turn the key off, the fans will continue to run for about 5 seconds until the relay shuts down. Your fan operation remains normal when the switch is off.

Engine Compartment Fan

Connect a wire to the ground of the relay located in the relay carrier behind the passenger seat, driver’s side. Relay #8. . Feed this wire to where your switch will be located. I simply fed the wire along the driver’s side of the car and under the door sill. Connect the wire to one side of the switch. Connect another wire from the other contact on the switch and connect the other end of this wire to a chassis ground point.

With key on, this switch will now immediately turn on the fan drawing air into the engine compartment. When you turn the key off, the fan will continue to run for about 5 seconds until the relay shuts down. Your fan operation remains normal when the switch is off. This mod helps keep the engine compartment much cooler when driving around town and is particularly beneficial to any engine that draws its intake air from inside the engine compartment, such as the EVO SC.

If you are adventurous, you can automate the operation of these switches so they will switch off at a specific speed, or operate when vacuum is present only, etc. You can choose any style switch you want and even use Porsche switches. I simply used 2 toggle switches that I installed in the batwing,

Jim

*** made this "discovery" back in about '00 in our '99 911/996. Hot, HOT day traveling across AR in stop and go construction zone traffic and the engine began to overheat because one of the front cooling fans had failed. Gave up on using A/C for a few miles until I came to the realization....

Necessity truly is the MOTHER of invention.

Acceleration and power is constant thru the RPM range. No lag at higher RPM. Middle RPM is much more responsive than before, and truly, I don't "put the pedal to the metal" often and I never redline the car. I do not use the car to track, just to drive around, more of a garage queen than a daily driver ( I travel alot) .After all has been said on both sides, I like the Sprint Booster, I do not think the way I drive the car that I am damaging anything, and it greatly increases the fun of driving my Pcar. I plan on putting the SB on all of my cars (BMW M3:manual and MB E-430:auto). Thanks for all of your imput, it has been an interesting conversation. JG ('04 C4S, Tip, Cab, Spd Yellow)

"..I don't put the "pedal to the metal" often..."

The way I read the SB documentation you don't need to, that's what the SB does for you, UNCONDITIONALLY.

Just went back and read "WHY IT WORKS" at the SB site.

Even simpler than I thought.

Lets say that your gas pedal puts out a signal voltage of 4.00 volts at the mid-travel point and 8.00 volts on the floor.

What the SB appears to do is "multiply" the gas pedal's positional sensor output voltage by ~2. So by the time your foot moves the pedal to the mid-point the engine ECU is seeing 8.00 volts and therefore more quickly goes to WOT.

Does that make the last 50% of gas pedal travel a "dead zone"...??

Or maybe it only multiplies the signal if it "sees" the gas pedal being depressed rapidly....??

I beleive the argument is, that the Sprint Booster puts undue stress on the transmission by shortening the gear changing time. The SB in no way decreases ( or increases) the time it takes the transmission to downshift or upshift. The timing of the shift is exactly the same as before. It does, however, increase the pedal responsiveness, especially in the mid-RPM range. The example that I gave originally, was that I was in 5th in Auto mode on the freeway, and I went to pass another car and when the transmission downshifted into fourth, in its own time, as I depressed the pedal, I got an immediate power surge, that I never had before the SB. Again, I am not here to promote the SB, but I personally have found it to be a great addition to the driveability of the car. We as Porsche owners go to great lengths to increase the speed and looks of the Porsche. We spend a lot of money on headers, mufflers, plenums, air boxes, ECU upgrades, etc. WHY? because Porsche does not! We already know that the Porsche in Europe is quite a different machine than the American Porsche. Certain models are available in Europe that are not available in the USA. So, I guess the argument is that either Porsche does not need to spend the extra dollars for these extras, or that they cannot spend the money due to regulations here in the USA. My second thought is that I have a 2004 C4S and technology has increase dramatically in the last 5 years. Just maybe, this technology was not around when my car was built. Remember the Pentium 3?

You're missing the point, entirely.

You are absolutely correct that the transmission shift, shifting time, is not affected by the SB.

Which is where the problem might lie. The standard e-throttle operation might allow for the time, full and complete time, for the transmission to accomplish a shift before allowing the engine RPM to quickly, too quickly, begin rising.

My concerns about this possibility are somewhat alleviated after reading the install procedure for the SB. I was confused as to how the SB could accomplish the functionality without interfering with PSM's ability to INSTANTLY dethrottle the engine when necessary so I went to the SB site to find out.

If the install information is correct then no one need worry about my point.

It appears that the only thing the SB has any capability of performing is to make the engine ECU think the driver is SUPER-HUMAN. Able to move tall...no, wait, that's another story line....

.....Able to move the gas pedal fully to the floor faster than the average human.

Someone will advise me if I'm wrong but the way I see it if the instructions are correct and the SB functionality is imposed between the gas pedal sensor(s) and the engine ECU than what other functionality is possible...?

... I don't try to pretend to be any expert on any subject when it come to Porsche mechanics. Few can. All I know, it that after I installed the SB on my Pcar, my acceleration is markedly better and more responsive. The shifting between gears is no quicker or slower. End of story.

I never heard of the Sprint Booster before, so I googled it, looked at their web site - http://www.sprintboostersales.com/ - and read their product info. From what I could tell from their specs, this thing only changes the throttle mapping, doesn't increase horsepower (per their web site), and doesn't improve 0 to 60 times (again from their web site). As far as I can tell, it doesn't do much other than making the gas pedal operate the throttle more aggressively in the lower RPM ranges, giving the illusion of power and speed. I'm not knocking the product, but does it do anything more than making the car feel faster?

The way I read the installation directions it installs between the gas pedal sensors and the ECU. Someone please correct me if this is wrong but IMO in that position ALL it can EVER do is simulate the "acceleration" the pedal travel to full "lead foot" quicker than humanly possible. And, obviously, no interference with PSM dethrottling.

98% snake oil.

Wwest, you are quite the soothsayer! Doom and gloom. You really have nothing to base your "predictions" on. It is evident that you have not even tried the SB and yet you have become an expert on the subject. I don't try to pretend to be any expert on any subject when it come to Porsche mechanics. Few can. All I know, it that after I installed the SB on my Pcar, my acceleration is markedly better and more responsive. The shifting between gears is no quicker or slower. End of story.

Sorry, but I just happen to know, absolutely FACTUALLY, that Toyota/Lexus are using e-throttle firmware "to protect the drive train" via inducing delays in engine RPM/torque rising until enough time has elapsed for the automatic transaxles to fully complete a shift, most especially a downshift where in the pedal position indicates hard acceleration requiring a "severe" (multiple level) downshift.

Not saying Porsche does that, but I simply wouldn't take the chance.

Oh, and how does SB "handle" the dethrottling function of PSM when the throttle plate MUST NOT "follow" the gas pedal.

Wwest, you are quite the soothsayer! Doom and gloom. You really have nothing to base your "predictions" on. It is evident that you have not even tried the SB and yet you have become an expert on the subject. I don't try to pretend to be any expert on any subject when it come to Porsche mechanics. Few can. All I know, it that after I installed the SB on my Pcar, my acceleration is markedly better and more responsive. The shifting between gears is no quicker or slower. End of story.

Sorry, but I just happen to know, absolutely FACTUALLY, that Toyota/Lexus are using e-throttle firmware "to protect the drive train" via inducing delays in engine RPM/torque rising until enough time has elapsed for the automatic transaxles to fully complete a shift, most especially a downshift where in the pedal position indicates hard acceleration requiring a "severe" (multiple level) downshift.

Not saying Porsche does that, but I simply wouldn't take the chance.

Screw, small part ingestion.

Since this car also has the paddle shifters, I can hard downshift into fourth anytime I want to. Usually I use the paddle shifters almost 95% of the time, the Sprint Booster just gives the gas pedal more control and more real acceleration without it. I used the example of the 5th into 4th scenario as a small example of what this can do. Just ask anyone who has a Sprint Booster if they returned their product back after the 30 day guarantee period. I'll bet most have kept the product and are really satisfied with the SB. Check the past threads on this.

I agree. Owners are not likely to experience the downside until 40-60,000 miles.

Just how much is a Tip rebuild...?

Brake fluid gets "old" in the same way the air used to inflate the tires gets old.

About a month ago, I installed a Sprint Booster on my 04 C4S Tip. I wanted to wait and see if I am completely satisfied with the product before recommending it to others. Well, I am here to tell you that this product is without a doubt the BEST addition that I have put on my car since I owned it. It has really livened up the acceleration. It has improved the driveability of my Tiptronic transmission remarkedly. I used to never use 5th gear on the freeway, because I thought that it made the car sluggish. Now in 5th,when I hit the gas pedal it jumps into 4th and I get this rush of power. I really feel the difference in the mid range RPMs when I need more speed it jumps up much more lively to the high RPMS without effort. The Sprint Booster has make my car much more fun to drive. (PS I have no affiliation with Sprint Booster and I paid the same money you would for the product).

And just how sure are you that the OEM e-throttle firmware wasn't written/designed to be "lazy"/slow in order to give the Tip clutches time to more firmly and fully seat, especially on a "hard", ACCELERATING, downshift....??

If you were driving a manual transmission what sequence would you use on the clutch/shifter/gas pedal...??

With the Tip you're pushing down on the gas pedal in order to initiate a downshift sequence, do you really want the engine RPM to be rising, EACH and EVERY time, before the Tip even "leaves" the higher gear...??

I had the front wheel bearings replaced by a new mechanic less than 10,000 miles ago and they now need to be replaced again. Mechanic claims he doesn't know the reason, but will replace again gratis. Question: What are the possible explanations?

Caliper piston, one side, not extending putting "bias" on bearing each time you use the brakes.

He probably means slow fade to off. If you add bulbs to one of those circuits you are chancing blowing the transistor, exceeding its IC rating, that provides the fade.

I believe the logic behind having only one rear foglamp (some Opel/Vauxhall manuals refer to it, I think properly, as a "fog tail lamp"), is that in fog or very bad weather, the driver behind can tell the driver's side of the car he's following.

From what I can remember, from a BMW 5-series manual in the '80s (English language, general export), in the Federal Republic of Germany, the rear foglamp is only to be used when visibility ahead falls below 50 metres (164 ft/55 yards) to reduce glare to the driver behind, and front foglamps if visibility falls below 100 metres (328 ft/110 yds). For the rear foglamps, that's about 10-11 car-lengths.

Also, from the manual, as the 5-series ROW cars had 7-inch outer (high/low beam) headlamps and 5-inch inner (high beam/driving) headlamps, the front foglamps are wired only to operate with the low-beam outer lamps. The manual said that in Germany, only four headlamps are allowed on at the same time, hence the wiring. (But it didn't say it was because high beams are useless in fog)

As a point of FACT fog lights when used in conjunction with low beams are actually a DETRIMENT to your night time distance vision.

Fog lights should ONLY be used alone in day time conditions that warrant their use.

Drivers who have fog lights on along with either high or low headlights are doing that only for BLING...!!

Most states REQUIRE the use of your main headlight beams between the hours 30 minutes after sunset until 30 minutes prior to sunrise.

I disconnected the "fog" wire and wired both of the "extra" rear lights into the brake circuit. Goal was to have a much more pronounced indication of brake application. I also wired my DRL circuit into the street/parking/tail/marker light circuit as is done in Canada for DRLs.

Verify that both raditor fans are on HIGH speed when AC is running. Not running on high speed will quickly raise the engine temps to those levels.

The description is exactly what I experienced years ago in AR in August in our 99 C2. I quickly discovered that one of the front radiator fans was not working and drove all the way home to Seattle with the A/C working and the engine NOT overheating.

The secret...

Turn the temperature control to MAXIMUM cooling "lo", recirculate mode, and then use the blower speed to control/regulate cabin temperature.

Bypassing the system's reheat/remix temperature regulation path results in lowering the heat loading of the radiator enough that I did not need to replace the fan until I got home.

Actually, it was your high speed driving and therefore full air flow over the condensers that kept temps down. My fans are always completely off running on the highway and AC running while maintaining <200F engine temps. Just short trips, like from Chicago to Vegas, :notworthy:

No, road construction all across AR was what first brought the problem to my attention. But yes, throughout the remainder of the trip as long as I was able to maintain a decent roadspeed the problem didn't exhibit itself, or wouldn't have were I not using the "procedure".

Verify that both raditor fans are on HIGH speed when AC is running. Not running on high speed will quickly raise the engine temps to those levels.

The description is exactly what I experienced years ago in AR in August in our 99 C2. I quickly discovered that one of the front radiator fans was not working and drove all the way home to Seattle with the A/C working and the engine NOT overheating.

The secret...

Turn the temperature control to MAXIMUM cooling "lo", recirculate mode, and then use the blower speed to control/regulate cabin temperature.

Bypassing the system's reheat/remix temperature regulation path results in lowering the heat loading of the radiator enough that I did not need to replace the fan until I got home.

Answered elsewhere.

Rebuilt CDI arrived from Loren at SC yesterday and seems to be the FIX...

LOX injection? :huh: (pardon my ignorance.)

LOX...Liquid Oxygen..

LOX "injection" would displace/replace the ~80% nitrogen on our atmosphere and therefore have the potential for increasing an engine's HP by 5X.

TRG's standards are pretty high but so are their prices.

When this first started happening we verified that the fuel pump relay was being energized and that was what was shutting the engine down. There are only three circuit connections that can energize this relay, a factory alarm, the air intake microswitch, and the rev-limiter. No factory alarm, no alarm at all, so only the rev-limiter has a possibility for latching up and thereby requiring a switch "off" before restarting.

The rev-limiter is now disconnected and the engine still shuts down so I guess the next step is to send the CDI away to loren at Systems Consulting.

Thinking about purchasing a 1988 Carerra in what appears to be excellent condition, both in and out. Anyone here live in AZ? Is the A/C sufficient for driving in the summer in Phoenix?Mesa/Tempe? Also looking for a reputable local shop that I can depend on to do things I cannot. Thanks, Bob..I am new to this site as of today!

I have an '88 911 Carrera Special Edition and the A/C is NOT satisfactory even here in the Seattle area. My current plan is to add a rear spoiler so I have room to mount a set (6..?) of 12 volt high volume computer cooling fans under the spoiler to force airflow through the rear lid mounted condensor.