SmokinGTS

Here is what I don't know. How does the RWS calibrate itself. I know we leave the key on when doing an alignment but exactly what is going on with the RWS. Does it turn a light on if the system is not calibrated during a self check or does it just throw a code that only the PIWIS can read. As I see it all the non dealership shops doing alignments are just hoping as I was that the RWS self calibrates to zero. Where I ran into problem is when mine didn't set itself to zero. We did the alignment and the problem didn't reveal itself until over 120mph. What I feel was happening was one rear wheel had a different toe than the other. During yesterdays alignment we turned the key on and waited and actually watched the Hunter alignment machines numbers change and didn't proceed until the RWS stopped with it's check. Until we know more about the RWS calibration process we are just along for the ride.

R.Deacon

^thks riding along behind you , it'll sort when shared

Larry Cable

at a very general level, I suspect that Porsche employs "precision error correction" techniques to re-calibrate the RWS motors and gearing ... which probably involves some cycling of the system from one extreme of travel to the other ... (basically to create a calibration between the 'distance travelled' and the input to the motor) not sure if it does this every time or only when initiated by some external (PIWIS) mechanism...
I would expect the system to 'park' itself centered upon stopping/shutoff.

Rapter

Hi everyone,

Was there ever any follow up by the members here if the RAS needs to be periodically re-calibrated?
Is the recalibration something that the end user can do?
Is there a “secrete hidden menu” or sequence of performed functions that promotes a “re-calibration” ?

Looking to perform a track alignment soon and would be good to “zero” the values pre-alignment.

RS Clubsport

Not sure about the re calibration of the RWS, but check for play in the units. My new to me Touring had 5k miles, had a set up done at Porsche and it was very dangerous at 3 figure speeds on the road, in fact I came close to having an accident and stopped driving it. When I had a local specialist check the geo there was play in both RWS motors, you could hear a knocking sound when moving the rear wheels. Replaced under warranty and the car is fine now. Certainly something to get checked if you have wayward handling, it allowed under braking/ unloading of the rear wheels over crests, for the small amount of toe in we'd set to become toe out!

Perimeter

If Porsche are using stepper motors, there is usually a two wire resolver in there somewhere to tell them actual position, but I don't see it on my GT3T (not saying its the same as anRS, rather that's all I have to look at).
I wonder if the calibration is inferred from other geometry sensors?

josephvman

I would be shocked if the system didn’t perform a self-check at every startup cycle, but that’s interesting to hear.

Bx Tpr

Searching for an alignment shop I’ve learned two things. The Hunter alignment machine actually requires the operator to keep the ignition ON when doing alignments on the GT3’s. Second, I’ve been told by two Porsche shops that a recalibration using a PIWIS computer is required.

Correct me if I’m wrong on the second point.

s4corrado996tt

Subscribed!

ClassJ

End of the day this is a belt driven actuator that can develop wear like anything else. If it is a stepper motor belt driving the actuator, a belt slipping a tooth would explain the situation.

hsb1001

System does perform a self check on every start up, I can confirm that as when I changed my battery it was one of the systems that gave me an error on start up during all the self checks.

Bruce R

I'll second this. The believe the RWS makes this car feel fidgety.

Larry Cable

my experience on track is the opposite, RWS on the GT3 has greatly contributed to the cars cornering capabilities vs. 997 gen cars...

the "virtual" longer wheelbase in high speed sweepers is very noticeably more stable.

groundhog

9000 track and tarmac rally kilometers, regular tire changes and alignments - no rear toe issues - no vibration at speeds up to 270kmh. Note drive shafts have had to be retightened. Also always have check alignment done before and after events.

The spec for the RS rear toe is 0.08 to 0.12 total toe 0.16 to 0.24 (thrust angle zero). Here are my last four checks - (1) 0.10, 0.11 (2) 0.09, 0.1 (3) 0.11, 0.10 (4) 0.11, 0.11.

I note that a lot of Euro/US track day guys run excessive negative camber for this car, particularly on the rear.

momo360

Anyone know a dealer in the Bay Area that would do this recalibration? I asked my service advisor at Burlingame, and he said he had no clue about doing a RWS calibration/never did it on any cars, but they could attempt it assuming it's a thing for $350. I was like yikes! no thanks.