...and i still like the completely different feel of GT3 steering setting in my early 991.1 S. i haven't had any issues.

alt theory, Adam, is that the default _is_the GT3 and all of the other maps are artificially adding something that some marketing person wanted. Porsche cars are race cars first so that makes sense.

see: what they did with the temperature readings

 

@AdamSanta85 I have read the arguments and I agree it is confusing.

I understand the logic you’re basing the argument on, ie software is in the component, and PIWIS just ticks the software options on, off or changes settings. That is solid.

I’m not a software engineer or Porsche product planner, but I’m unsure if bc the GT3 wasn’t released to the public means / doess not mean the component supplier was / was not including the software already in builds of the hardware (ie the EPS rack/motor/etc). Product development takes awhile and launch dates move up and back regularly.

Let’s look at dates. This is not meant to be argumentative, rather trying to break this mystery down. I too am puzzled by this. It would seem that my car would not be able to even be coded to “GT3” EPS software.

• Aug 2012 - Spy photo of GT3 at Nurburgring etc - also spy photos of GT3’s around Europe published without camo and real dashboards. If it’s on that track, GT3 software (even if beta) exists.
• Late 2012 - My C2S was built
• March 2013 - 991 GT3 was introduced March 2013 at Geneva.
• May/June 2013 - Chris Harris drove and other UK/EU reviewers drove - and published in June 2013 all published around June 2013. Software deffo done at this time.
• This means the components for these cars were built early 2013. .... Which means the software was probably finalized sometime before that.
• The earliest 2014 GT3’s to hit the US were built in maybe October- November 2013. Ish?

Plausible that Porsche was futzing with software from late 2011 at the launch of 991.1 Carrera all the way up until GT3 launch? Maybe? Or not. Perhaps this is the explanation as to why the GT3 software is accessible on all early 991.1 Carreras? But we get an error because of some 'checksum or other coding verification issue’ as others have speculated.

A few other points:

• Why would PIWIS not be intelligent enough to lock us out of coding options that simply do not work? Seems pretty obvious. IDK though. Not a PIWIS Jedi here.
• I've not yet run into a failsafe mode for an engine, steering, transmission or other component on a car that didn’t completely neuter the component or driving experience. Engines lose all power, transmissions start in 3rd gear or don’t shift, that sort of thing. When something is in limp mode, it limps. It’s obvious. This is not that. At all. I’m making vast and dumb assumptions, so this is probably a garbage point to make. But - it does seem to make some anecdotal sense based on my automotive history.
• EPS was controversial on the 911 when 991 came out. In the launch technical documentation, I can find no mention of failsafe mode in any launch or subsequent docs. Maybe I don’t know where to look. (again, making lots of assumptions)
• The improvements that owners of, for example, 2015 GTS models document here and elsewhere when adding GT3 steering coding seem to be exactly the same improvements I note on mine with the yellow error message, when I select GT3 steering. Characteristic for characteristic, it matches. This is not seat of the pants imagination as can happen with performance modifications... or group think. It’s a real difference and pretty simple to tell the differences.

Anyway, maybe you’re right. Maybe I’m right. Maybe we’ll never know. I do know next time I meet someone who is actually employed in a technical capacity by Porsche I will bring this up. And hopefully I do not go sailing off into a ravine because I’ve hacked my 991.

After 200-210 miles of driving, the GT3 software is a notable and welcomed improvement to my C2S. I’m going to keep watching it and seeing if I notice anything else. The one guy @vincenz0 who noted a domino of other negative effects is surprising and he’s quite smart. So -- yeah. Mystery. Not solved.

 

This logic makes sense to me as well. On the other hand, the 991.1 GT3 was released in 2013 in Europe, if I recall correctly. That means it would have been in development at least two years prior (2011). Given that, it makes sense that 2012 cars could have a beta or engineering sample code for the GT3 steering.

I’d guess, though, that it was refined and validated by the time the 991.1 GT3s went into production in 2013. The validation process may also explain why later cars don’t throw an error—perhaps there’s something in the code that confirms its completion (like a certificate or similar mechanism).

Regardless, I sourced a 2016 rack and plan to install it in my 02/2012 car. I’ll share the details eventually—just need to find the time to do it.

 

Love the investigation and discovery going on in this thread. I recently got my PIWIS 3 setup up and running and figured I’d share my results. I have a 2014 C2S and unfortunately I get the error code when GT3 steering config is enabled. My car also has Power Steering Plus (PSP, which I dislike). Setting the EPS to GT3 absolutely made a notable difference when driving and also notably disabled PSP which was great.

I don’t like the idea of suppressing warnings so I switched back to stock C2/S config until we know more. I think the hypothesis that the software program exists on the EPS module and the PIWIS simply tells the module which config to use makes the most sense. If that’s the case, I’m guessing that the GT3 software on the early EPS modules were either beta or worse, incomplete. Seems like the only way forward for folks like me would be an updated firmware for my EPS module. Subscribed to this thread in case anyone figures it out.

Anyways, here’s the info for my 2014 C2S which throws the EPS faults when GT3 mode is set:
Part number: 99161814706
DSN: 000004
Software version: 1330
Hardware part number: 99161814706
Hardware version: 011
Steering Porsche PN: 99134700513


 

I had a 2016 C2 base Black Edition that I coded to GT3 Steering using a PIWIS 3. After making this change, I never encountered any fault messages.

My experience was a bit different from the common consensus here—I found the change in steering input and feedback to be subtle, not the dramatic "night and day" difference often mentioned. Interestingly, switching to GT3 Steering also seemed to blur the difference in suspension feel between Sport and Sport Plus modes. It's worth noting that my car had the stock PASM controller replaced with a DSC controller, making that observation even more perplexing.

In my opinion, if you're getting error codes after changing to GT3 Steering, it might indicate the EPS module defaults to a generic configuration when it can't find the specific named configuration. Ironically, this default setup might actually feel better than the standard steering map.

Hank

 

If you really want to change the steering feel for about $250, but you lose your airbag.

Just get one of these cup car steering wheels LOL

That's what I did, and love it.

 

tried this today using my piwis 3 on my 2014 991.1 turbo S but it failed. It did work doing it in my friends 991.1 C2S though, and anothers 981 boxster S, both said it is def an upgrade, and noticeably better steering feel. i think it failed in mine because i have rear axle steering. Also my EPS module showed version A2_3 in the PIWIS, but his was A2_2, not sure if that made any difference as well. in the dropdown menu i did see 918 spyder option as well, and im tempted to try that in my car.

has anyone ever tried coding the 918 spyder steering setting?

 

991.1 Turbo variants have a different steering rack.

 

ahh ok that explains then why it failed.

EDIT: i went back in PIWIS, and noticed there is a GT3RS setting, i know that has RAS so i tried it and it worked! Immedietly took the car for a test drive, but didnt notice much difference. Nothing like what you guys have mentioned when coding carreras to GT3 steering. The steering just felt a little heavier at all speeds, not necessarily better or worse. Wasnt too exciting, but ill keep this setting for a while and see if i notice more differences or just go back to the normal turbo S steering setting. Im thinking with the RAS cars, software change cant really have a big affect on the steering.

 

Really excited to hear how your rack replacement goes for all the 2012 and 2013 911s out there! I'm firmly in the camp that errors mean it's a half baked software in the older racks and depending on the specific version could be better/worse. As someone looking to add an early 991.1, I'd probably lean towards a replacement rack to ensure I'm getting the right sauce.

From my research, the steering rack appears to be Bosch steering Gear KS00002888. FCP Euro made the connection, but verify before buying.

 

Oddly coincidental timing — I’m actually in the middle of swapping the rack right now. I’m far enough along to confidently say that the newer rack doesn’t trigger any errors and unlocks additional options like GT4, GT3 RS, etc. They all show up as expected. I still need to code it and get the car fully reassembled before taking it out for a drive, so stay tuned for impressions.

 

Just a comment to those selecting “GT3” steering on older 991.1s and receiving an error message:

These codes that we alter are by and large “variant coding” - they are pointers in the software that instruct the ECU to use different addresses for some parameters. E.g. the variant code for model designation may instruct the EPS controller to use different assistance maps or gains. It seems highly unlikely that Porsche / their suppliers would have their homework for the GT3 done so far in advance that the calibrations would be available on 2012, early 2013 cars. The most likely phenomenon here is that the enumeration for GT3 points to default calibrations, and falls outside the range of what an early EPS module would have been calibrated to accept as “valid”, hence the error. I’ll be interested to see how the rack (and therefore EPS module?) replacement goes.

That said, if you like the uncalibrated SW better than the released cal, more power to you. I don’t know the specifics for Porsche in this case, but I’ve been doing embedded SW and calibration for OEMs and suppliers for a little over a decade.

 

well, the GT3 Cup and GT3 RSR were already using EPS in 2011

and here's Rohrl talking about developing EPS for the Carrera S in a 2012 article.
https://www.carmagazine.co.uk/car-ne...ng-with-rohrl/

 

I’ll be the first to say my comments are conjecture, but I’d give it better-than-even odds that it’s close to what’s happening for early 991s that try to reconfigure the EPS as GT3 calibrations.

 

i know i sound weird and butthurt arguing for this but if you read through the troubleshooting process we went through two years ago when this came up we discussed that possibility.

i put the car into other modes and drove around.
-the 4S mode gave the error and steering feel was just like the 2S.
-there was another mode that wasn't the GT3 mode that threw the error and felt different from the 4S or 2S modes.
-the GT3 mode throws error and steering feels more like my 993.

so all modes besides the one for the car had the same error and those other calibrations were clearly ready for production.


anywho

got a new steering wheel to match my awesome, perfect, problem-free GT3 calibration. :P