Guys, if you can believe it we haven't had much if any rain in the 50 days and 1,500 miles that I've had the Blue Zoomer. I guess that's why Florida is called the Sunshine State. Well, it's been raining non-stop for the past 20 hours. And of course, I've been driving the Porsche in the rain.

The 997 absolutely loves the rain. Indeed, it's a fun car to drive in the rain. The car seems more planted than my '03 996 on slick roads. The back end doesn't even give a hint of wanting to slide in turns. The car has great traction.

I performed one fun little test, my dream of being a Porsche test driver once more getting the best of me. Driving on a 45 mph four lane road in a downpour yesterday afternoon no one would let me in the left hand lane so I could avoid the multiple 8" pools of standing water along the gutter. So, what the hell, I just drove right through them with my foot planted firmly on the gas, the tires on the right side of the car throwing up huge waves of water. The PSM light came on intermittently at first but the car tracked straight as an arrow and I was easily able to maintain 45 mph. Honestly, with one half of the car in a virtual flood, I was amazed and very impressed with the car's tracking ability. If you're thinking about getting a C4 for greater stability you need to know that the C2 is truly incredible in its own right. I can't see the AWD being necessary in anything but snow.

I give some credit to the Michelin PS2s. I've always loved Michelins in the rain. In fact I'm waiting for UPS to drop of a set of Pilot LTXs for our Yukon right now. And I run Pilot Sport A/Ss on our Audi. But there is definately something to be said for traction benefits of the classic rear engine/rwd 911 setup.


One feature I'm really beginning to appreciate is the rain sensing wiper system. Guys, is this cool or what? But I have one question for you: how does the system work?


Well, I'm off to Birmingham on Monday for my second PDE master's course. It should be about a 1,300 mile round trip. I have a wonderful route devoid of interstates planned and a nice B&B on a lake not far from the Barber track reserved. I am absolutley popping out my skin with excitement.

 

The system uses an infrared sensor aimed at the windshield and when some of the IR signal returns scattered (because of the presence of water on the glass) it turns on the wipers.

Dan

 

Rain Sensor and Intermittent Settings
The rain sensor on vehicles so equipped measures the precipitation on the windshield, including snow. Correspondingly, the wiper speed/frequency is automatically set between intermittent to continuous (Stage 1 and Stage 2). The rain sensor function supercedes thet interval function.

The following will activate the rain sensor:
Setting the wiper lever from Neutral to Stage 1
Operating the windshield washer system
Changing the rain sensor sensitivity with the thumb wheel.
Activation of the rain sensor is confirmed by a single wipe of the blade.

Function
Increasing the sensitivity by the potentiometer on the wiper switch triggers a single wipe cycle, thus transmitting information to the rain sensor via the serial interface. During the pauses in wiping, the wiper is placed into a raised "Interval Parking" position and is protected against backlash by the motor.
Activation of the intermittent operation immediately results in a full wipe cycle. Thsi does not occur, however, if the intermittent function was active before the ignition was switched on. If the rain sensor does not receive a signal after a specified period, the intermittent operation stars with one wiping cycle. The interval pause is determined by the wiper set point, vehicle speed and potentiometer value.
The wiping speed during intermittent operation corresponds roughly to Stage 1. Shortening the interval pause on the potentiometer triggers a single wiping cycle.

Automatic Reduction of the Wiping Frequency
This function is activated after the ignition is switched on (terminal 15) and the vehicle achieves a speed of > 5mph. If Stage 2 has been selected and the vehicle speed is greater than 5mph, the wiper operates at Stage 2. If the speed goes below 2.5mph the wiper speed switches from Stage 2 to Stage 1. If the vehicle speed increases again to > 5 mph, the wiper, depending upon the lever setting, will run at Stage 2.

If Stage 1 has been selected, the wiper speed is set to Intermittent if the vehicle speed is < 2.5mph. The interval pause period is 4 seconds. If the vehicle speed returns to above 5mph the wiper again operates at Stage 1.

Automatic decrease of wiper speed is interuupted by a function modification on the circuit. The automatic decrease in wiper frequency resumes after the vehicle speed reduces from > 5mph to below 2.5mph.

from a discussion in the Cayenne forum:
https://rennlist.com/forums/cayenne-955-957-2003-2010/235171-rain-sensor-wipers.html

 

I hate those automatic wipers sensor. It messes up your windshield and wiper blades when there is only a few sprinkle at the sensor area.

 

I suppose you could cut out a small circle out of black shiny tape large enough to cover the sensor to render operation strictly manual. I might even consider that, if I used my 911 as a daily driver and didn't want a few sprinkles to be the cause of my windshield smearing up.

 

If the system uses an IR beam, what would happen if I point the TiVo remote at it?
Could I pause the wipers? Make them wipe in three different speeds? Schedule the wipers to come on at a given time from the comfort of my office?

 

Absolutely! (Is there any wonder when the instruction manual on this car is in excess of 300 pages!!)

Did you get the car yet??

Dan

 

Hey AeroSmith!

Tell they guys I say "Hi" (John with the number 35 Club Coupe) and that we will see them in March!

 

Got a ? about the wiper system. I have the rain sensing wipers and memory, in the manual it claims I can set wiper settings on the PCM screen but I can not get the system to work like the manual states. All I get is PCM SYSTEMS and Main Settings no memory settings and wiper settings. The dealer had no idea . Also about the tires. In the last Car n Driver they tested tires. The BFG G-FORCE KD seems to be the best tire for dry pavement and since I may only use the rain sensor wipers twice a year in so cal what do you think? Who needs wet traction. Has anyone bought these for the 997s yet?

 

Hmmmm, I leave it off until it really starts raining. Otherwise I use the manual swipe by pushing down on the contol stalk.

 

THANKS.

 

My wife has the auto sensor wipers in her Lexus and they drive me nuts.

jmtc,
Rob

 

yup, everytime I drive my wife's RX330 I would need to turn that thing (and the automatic headlights) back to manual