Firstly, Kudos for testing along the lines you did, love it. Like you, I am always looking for objective data and not jut subjective "feel" when I am changing things.

I have a 2012.5 991.1, No DSC and I did not feel harsher PASM..

that said, I live on a rough ( compared to Suburban roads) rural country road, my car has ****ty PZeros ( awaiting MP4S N0 to show up )

I also didn't notice my PASM get harsher on my '16 GTS when I activated GT3 software.

 

How interesting. My car is not equipped with PASM so I don't have any way to test this. I'd be curious if the unusual PASM behavior correlates to the error code thrown by early build dated cars. Would be helpful if you had access to a later build 991.1 with PASM that doesn't throw a code for you to run the exact same test on.

 

I gather from the previous posts that maybe @desmotesta lives in the SF Bay Area too but I think he also has an early one that throws the error.

I was thinking about this a little more today and I have a couple of theories but I'm not sure how to validate either of them, open to suggestions!

Theory 1 - When you switch to the GT3 steering calibration, it actually does also firm up the PASM suspension tune as well.
This could make sense as a more stiffly damped car generally gives a feeling of more responsiveness. Porsche engineers are smart, and they're astute drivers. I've always said when driving my 911 that it was engineered by people who appreciate driving. So it's not inconceivable that the steering and suspension settings would be somehow linked. I wonder if there is a way to find the PASM settings somewhere in the PIWIS modules and see if they change when GT3 is selected.

Theory 2 - The error code actually causes some failsafe or in some way puts the car into a weird limp mode
Not a full on limp mode like you would think with more extreme malfunctions. But when I had the GT3 calibration active, I did feel like multiple aspects besides just the PASM felt "off". Throttle response seemed a little different, engine power delivery felt a little different, the transmission seems to shift (especially downshift) a little different. Again, I didn't quantify any of these things but I do drive this car every single day all year round (and have been for 4 years) so I have a pretty good baseline of what it feels like when everything is "normal."

I'm considering buying a DSC controller (I was thinking about getting one anyway) just to check if that makes a difference to the PASM part of it. I suspect it would. I also probably should do some more testing on the same stretch of road to eliminate variability just a low number of samples/tests.

I haven't given up on the GT3 setting yet (because the steering did feel good!), but I want to really understand what's happening.

 

This is awesome thinking. I like how you try to explain with data instead. I tried the GT3 setting for a bit and switch back. It didn't feel right, something feels better, and something else felt off, but not sure what it was. I would like to see what you'll find.

 

@Cadubya I was wondering if you could elaborate on what "soft codes" (I assume you mean soft error codes) you saw on the PSM? If you no longer have them, I can try to run a diagnostic on my car after with the GT3 setting active.

 

Early build '13 C2 with PASM here. @nhnguy12 did my car not long after I bought it so I don't have much of a reference point but can contribute that I love the mod and don't notice any of the aforementioned PASM weirdness. Not that I can tell anyway.

 

I think this may be it. One of the positives with the DSC controller is that it increases the total range of stiffness for PASM in both normal and sport settings, but especially in the sport setting.

From DSC:
So if the GT3 steering setting did somehow affect suspension settings, a DSC controller would seem smoother than the stock PASM controller.

 

Switched back to the GT3 steering today and made a few observations aside from the PASM suspension already noted, will try to figure out a way to quantify these:

1. PDK transmission shifts are more abrupt / clunky, especially on downshifts (normal driving, not aggressive driving)
2. PDK transmission sounds different - less of the typical "high tech gear whine"
3. Rear engine fan speeds sounds like they are at max speed despite not being a very warm day (~74 F) (normal driving)
4. Engine idle slightly rougher
5. Throttle response feels different, not like sport mode but like a 1/2 sport mode almost
6. The way the engine pulls under hard acceleration feels different. Revs a little bit freer but also feels like less torque. I need to experiment with this some more.

When the GT3 steering setting is enabled the car just feels a little "off" for lack of a better term. I want to do some more back to back testing but I'm pretty confident that at least on the cars with the error displayed after switching to the GT3 steering, something weird is going on. If that's the case, it could be the reason why there is no official Porsche TSB or anything to upgrade the 991.1 steering.

I'd love to figure out more about what's going on here. Any Porsche engineers lurking in the forum?!

BTW I did use the PIWIS 3 to scan for fault codes as mentioned in an earlier thread, but nothing out of the ordinary detected other than the error with the GT3 steering coding.

 

You guys with the error should find a friendly dealer that will update the firmware on the power steering module, then you will get the GT3 map.

The “maps” live on the module on the car, the PIWIS/ThinkDiag etc just toggle settings based on software on the device. The error is the power steering module saying “no map found” essentially

On the 992 GT forum there are guys updating the firmware on their PASM modules so they can code the S/T setting… same story

 

Has anyone successfully had their firmware updated on early 991.1’s? I’ve not heard of anyone on here that’s had a dealer do it.

 

I unfortunately didn’t document the error codes. I say soft, because they didn’t trigger any warnings in the instrument cluster.

 

Wow I just read through those threads and those guys are way smarter than me haha. Flashing new firmware is certainly a larger job than changing the settings within the modules like I've been doing. I hope someone pursues this and keeps us in the loop on how it's done.

 

I think the maps there, otherwise there won't be any changes in other parameters. Just like some can see a GT3RS option and some don't , and those that don't doesn't have the map. As for the warning, it could just be a hardware compatibility warning, like how windows or android tries to warn you about an app that may not run properly but it works fine in general, but may be buggy due to newer API req that doesn't exist in the HW. Don't know.

 

My car has a December 2011 build date, this was long before the GT3 was released so I wonder how it could have the GT3 calibration on the module? (Even if the GT3 were in development then they probably wouldn't have had the calibration ready for production steering racks.) Thus the error code as someone mentioned above.

So what we're likely feeling (in this case) as the difference is probably a change to a default non-modified calibration that the manufacturer of the steering rack sets.

That'd also explain why later cars do have the GT3 setting.

Also I think the options shown in the coding screen are PIWIS version dependent maybe?

 

i tested the default setting theory way back when this first started. errors occurred for all settings except the original but the feeling of the steering is very different and in GT3 mode it was much more like what i wanted. that's why i kept it and suppressed the error.