981 Steering Remap
Discussion
I've got a Cayman 981 GTS. It's a fabulous automobile in many ways but the steering feel at speed for me is a let down. I don't want to start a fight here about if it's an issue or not (as opinions are like....noses etc. 
) but I have found an interesting thread on one of forums in the United States of Freedom.
One of the users found he could add a different remap to the Electric Power Steering (EPS) to change it to 991 GT3 map which has the same steering rack part number (using PIWIS). It's been getting pretty much only positive responses and has got me interested.
https://rennlist.com/forums/981-forum/1339917-upgr...
He makes a case as to why this may be an upgrade:
) but I have found an interesting thread on one of forums in the United States of Freedom.One of the users found he could add a different remap to the Electric Power Steering (EPS) to change it to 991 GT3 map which has the same steering rack part number (using PIWIS). It's been getting pretty much only positive responses and has got me interested.
https://rennlist.com/forums/981-forum/1339917-upgr...
He makes a case as to why this may be an upgrade:
Some Random Guy on the Internet said:
I believe the EPS software for the non-GT 981/991.1 was Porsche's first attempt at using this type of steering rack. It clearly wasn't perfect and a lot of motoring journalists pointed this out during the time of release (2011-2012). A year or so later Andy Preuninger (head of the GT department) and his team got their hands on the software and tuned it over tons of track hours:
Whatever they did worked and the 991.1 GT3 (~2013) was lauded for having the best electric power steering in any car made up to that point (per Chris Harris and other prominent journalists). But Porsche had zero financial incentive to retrofit this improved software into the outgoing models of non-GT 981/991.1 cars. Like all companies they are in the business of making money so why would they do that for free if people are already happily buying the outgoing cars. Instead they saved these updates for the next generation of cars and marketed it as one of the reasons why people should drop a bunch of cash on a brand new car. That's why the non-GT 718 and 991.2 cars are regarded as a return to form in the steering department, even without the fancy suspension components.
Any thoughts on this one? Whatever they did worked and the 991.1 GT3 (~2013) was lauded for having the best electric power steering in any car made up to that point (per Chris Harris and other prominent journalists). But Porsche had zero financial incentive to retrofit this improved software into the outgoing models of non-GT 981/991.1 cars. Like all companies they are in the business of making money so why would they do that for free if people are already happily buying the outgoing cars. Instead they saved these updates for the next generation of cars and marketed it as one of the reasons why people should drop a bunch of cash on a brand new car. That's why the non-GT 718 and 991.2 cars are regarded as a return to form in the steering department, even without the fancy suspension components.
David W. said:
Clearly if power steering + (PST?) is a software thing other parameters could be changed as well. Something for Lichfield or others?
I think you're right....in theory! I get the sense that there is a dedicated bit of software (that runs either on a dedicated board on the rack or in the CPU) that controls the how much assistance the EPS is giving based on a range of inputs. Using the PIWIS you upload a different bit of EPS software tuned for the GT3. How you extract that bit of software, decompile it and rewrite it would be as hard as doing the same for an engine map but there's probably not the market to make it worthwhile.TGCOTF-dewey said:
But the parameters within the GT3 software will be predicated on the GT3 geometry and components.
So it could work or equally not given the differences - and geo makes a huge difference to steering feel.
Yup completely agree - 1000s of hours of Porsche engineer time have been spent tuning the GT3 EPS map for GT3 rear-engined mass, suspension and steering kinematics not to mention the active rear wheel steering. But if it lowers the levels of assistance at fast road speeds I still think it could be an improvement. And if it's not, you can always flash it back to standard!So it could work or equally not given the differences - and geo makes a huge difference to steering feel.
seefarr said:
David W. said:
Clearly if power steering + (PST?) is a software thing other parameters could be changed as well. Something for Lichfield or others?
I think you're right....in theory! I get the sense that there is a dedicated bit of software (that runs either on a dedicated board on the rack or in the CPU) that controls the how much assistance the EPS is giving based on a range of inputs. Using the PIWIS you upload a different bit of EPS software tuned for the GT3. How you extract that bit of software, decompile it and rewrite it would be as hard as doing the same for an engine map but there's probably not the market to make it worthwhile.TGCOTF-dewey said:
But the parameters within the GT3 software will be predicated on the GT3 geometry and components.
So it could work or equally not given the differences - and geo makes a huge difference to steering feel.
Yup completely agree - 1000s of hours of Porsche engineer time have been spent tuning the GT3 EPS map for GT3 rear-engined mass, suspension and steering kinematics not to mention the active rear wheel steering. But if it lowers the levels of assistance at fast road speeds I still think it could be an improvement. And if it's not, you can always flash it back to standard!So it could work or equally not given the differences - and geo makes a huge difference to steering feel.
981Boxess said:
If there is an oven ready (thanks Boris) software that is an improvement does it matter if it isn't 100% bespoke for that application?
No, if it genuinely does. However, the GT3 software has been validated on a completely different platform across all areas of the performance envelope.
It may offer improvements at 6-7 tenths as per the review in the link. But who's to say at 8,9 or 10 tenths it doesn't do something weird?
That's the problem with safety important software.
I've used 20, 19 and now 18 inch wheel tyres on my 981 and they do feel different. Jumping from the 981 to a 996 you immediately notice the steering feel change. I've been toying with the idea of removing the assisted rack altogether but as no one else seems to have done it then this could be a lonely road of bleeding edge learning for me. I'd be interested to hear back from anyone here who tries this so please keep us posted.
Geo, tyres and a reset of the steering angle sensor after any adjustment do wonders for the steering in the 9x1. If yours is off try the reset after adjustment it's often missed especially if your car was aligned outside the opc.
I've also tried the setting, I think it's just optimised for the GT3 geometry, I agree that it is slightly better but nothing scientific to back it up.
I also noticed a slight change when turning in car parks but there wasn't anything drastically wrong with the steering in the first place. In the wet you just need more wheel time to know and trust the car, I suspect the people generally complaining went for a test drive once after being used to the previous hydraulic system.
I've also tried the setting, I think it's just optimised for the GT3 geometry, I agree that it is slightly better but nothing scientific to back it up.
I also noticed a slight change when turning in car parks but there wasn't anything drastically wrong with the steering in the first place. In the wet you just need more wheel time to know and trust the car, I suspect the people generally complaining went for a test drive once after being used to the previous hydraulic system.
Edited by testdrive on Thursday 10th August 04:37
Steering feel has always been an elusive thing for me.
I’ve had 3 981 Cayman GTS and I’ve never felt the steering was a let down. Fabulous cars.
I’ve also owned a 991.2 manual GT3 and the steering feel didn’t blow me away there. I know it’s not hydraulic, but still it was a wonderful road car where you felt connected and involved the whole time.
What would be a good car to seek out to experience benchmark steering feel, hydraulic and assisted?
I’ve had 3 981 Cayman GTS and I’ve never felt the steering was a let down. Fabulous cars.
I’ve also owned a 991.2 manual GT3 and the steering feel didn’t blow me away there. I know it’s not hydraulic, but still it was a wonderful road car where you felt connected and involved the whole time.
What would be a good car to seek out to experience benchmark steering feel, hydraulic and assisted?
Edited by CloudStuff on Thursday 10th August 14:41
CloudStuff said:
Steering feel has always been an elusive thing for me.
I’ve had 3 981 Cayman GTS and I’ve never felt the steering was a let down. Fabulous cars.
I’ve also owned a 991.2 manual GT3 and the steering feel didn’t blow me aware there. I know it’s not hydraulic, but still it was a wonderful road car where you felt connected and involved the whole time.
What would be a good car to seek out to experience benchmark steering feel, hydraulic and assisted?
Unassisted 911 3.2 had the best steering feel I have ever had, Lotus Elise was pretty good alsoI’ve had 3 981 Cayman GTS and I’ve never felt the steering was a let down. Fabulous cars.
I’ve also owned a 991.2 manual GT3 and the steering feel didn’t blow me aware there. I know it’s not hydraulic, but still it was a wonderful road car where you felt connected and involved the whole time.
What would be a good car to seek out to experience benchmark steering feel, hydraulic and assisted?
So I had this done at GT One today.
And I'm almost certain it made quite a positive difference for £36 of labour! It's all very subjective and it can be difficult when you go looking for a difference, you may find it even if it's not there but it's better. Even driving through train-strike London traffic, there's more of a ripple of feedback of what's going on at the front wheels. I had one mercifully clear "40" section and there is certainly more feedback in corners - it loads up with weight in a natural way as the front tyres are under load and if you wind off lock or back off, it lightens up. It's a lot like steering feel!
But the only way to be sure is to find some nice empty roads so on Friday I'm getting the ferry to Spain and Portugal, just to be sure. For science!
I'll provide detailed feedback (mainly about jamon) here:
https://www.pistonheads.com/gassing/topic.asp?h=0&...
And I'm almost certain it made quite a positive difference for £36 of labour! It's all very subjective and it can be difficult when you go looking for a difference, you may find it even if it's not there but it's better. Even driving through train-strike London traffic, there's more of a ripple of feedback of what's going on at the front wheels. I had one mercifully clear "40" section and there is certainly more feedback in corners - it loads up with weight in a natural way as the front tyres are under load and if you wind off lock or back off, it lightens up. It's a lot like steering feel!
But the only way to be sure is to find some nice empty roads so on Friday I'm getting the ferry to Spain and Portugal, just to be sure. For science!
I'll provide detailed feedback (mainly about jamon) here:
https://www.pistonheads.com/gassing/topic.asp?h=0&...
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