[EPS Coding] Two New Variants Found: F80/F82/F83_rep & F87CS

[packetpilot]

[original title: "EPS Coding: Is it true?"]

I've had several customers tell me they can't find anyone else who does EPS conversions to GTS [edit: the following parenthetical is INCORRECT for v 60.1](/M2, which share the same parameters so it seems). [<= WRONG FOR NEWER SOFTWARE sometime beyond 58.3]

I've also had reports (one as a response to my earlier post) that doing so could be catastrophic.

None of the many I've done have resulted in catastrophe, thankfully, just a tighter-feeling car near-/at center wheel position, and of course a lot of very positive feedback from those whom I've converted.

Why the aversion, if there is an aversion, among "more established" coders?

[packetpilot]

Here's some more info that I spitballed with a friend.

friend:
so when you say the steering coding is the same as M2 and GTS, does that mean the zcp is the same too
since the configurator says "Direct steering ratio" lol

me:
[finds link]
http://f80.bimmerpost.com/forums/sho...d.php?t=960886
"the torsion bar measures the torque applied by the driver and in turn controls the EPS motor. The angle is applied by the driver, while the power is provided in part by the EPS motor."
...to me that sounds a lot like the settings changes, if the parts are the same, are more of a function of the input damping parameters from steering wheel to the EPS controller/motor.
and perhaps on normal cars there was "a lot" of damping/input slow-down (or straight bypass filtering) near center.
[...]
The M2 and GTS are the same in that there's this field with german words surrounding the word "variant", and the value it's set to says both M2 and M4GTS; both names are in the same choice.

friend:
gotcha, looks like the official steering ratio of the m2, m3, m4/gts are all 15:1
so it's probably just the damping
like you mentioned

Also, the ZCP has tighter steering, not just the GTS, as per BMW's own ZCP verbiage in their new configurator:

Experience pure high-performance and ultimate motorsport feel with the specially developed Competition Package. The enhanced dynamics deliver faster acceleration (-0.1s for 0-60 mph), which come from a horsepower increase of +19 to 444hp (vs. 425), more direct steering ratio, Adaptive M Suspension with new settings in all 3 modes, New DSC setting and New setting for Active M Differential.

[terahertz]

I'm not really sure what they mean by more direct steering "ratio". That would be a hardware change if they really changed the ratio of the rack. To me it just sounds like maybe a marketing person got their words wrong. Does ZCP have a different setting than civic? I kind of don't think so.

I did the EPS coding, minus the signature part. It feels better to me.

[packetpilot]

Originally Posted by terahertz

I'm not really sure what they mean by more direct steering "ratio". That would be a hardware change if they really changed the ratio of the rack. To me it just sounds like maybe a marketing person got their words wrong. Does ZCP have a different setting than civic? I kind of don't think so.

I did the EPS coding, minus the signature part. It feels better to me.

"More direct ratio" is definitely through a marketing lens, but to paraphrase the spitballing with a friend, I have a feeling it's "more direct when normalized across a range of +/-1 std deviation from the center"... if that makes sense. More simply put, the elimination of the dead zone.

I've only ever done it via VO coding so haven't actually futzed with actual coding parameters, to 'stay safe' ...but now I have a feeling I'm going to get a bit more daring.

Hopefully I'll have more input surrounding whether Civic => ZCP => GTS each have their own deltas, or if it's Civic => ZCP==GTS. Same with GHAS. Homework. ;-)

[packetpilot]

Maybe I should ask M2/GTS drivers to let me make their steering shittier for a day. Maybe that's the ticket to really get an idea of how damping/input is changed, short of actual science. I have a feeling noticing when things get worse is easier than when things improve.

[terahertz]

Originally Posted by packetpilot

"More direct ratio" is definitely through a marketing lens, but to paraphrase the spitballing with a friend, I have a feeling it's "more direct when normalized across a range of +/-1 std deviation from the center"... if that makes sense. More simply put, the elimination of the dead zone.

I've only ever done it via VO coding so haven't actually futzed with actual coding parameters, to 'stay safe' ...but now I have a feeling I'm going to get a bit more daring.

Hopefully I'll have more input surrounding whether Civic => ZCP => GTS each have their own deltas, or if it's Civic => ZCP==GTS. Same with GHAS. Homework. ;-)

When we figured out Civic to ZCP a year ago, there were no EPS changes. Would make sense since the other werte value specifically says M2 and M4 GTS.

You shouldn't be afraid of changing the parameter. There are tools which you seem to have that will tell you what would change if you VO coded. It's the same thing if you make the change yourself.

[packetpilot]

Civic and ZCP are indeed the same with 16_11_502 and 0715 build date.

GTS changes the variant and signature.

There's also a couple variants I hadn't noticed before:
F80/F82/F83_rep (repaired?)
F87CS
Hmm...

Also: I was apparently confused about the M2 sharing the GTS settings. Might've been confusion with another ECU[incorrect], or maybe it's because my car is in a newer I-STEP than the many recent targets I've had [<= correct].

[terahertz]

Originally Posted by packetpilot

Civic and ZCP are indeed the same with 16_11_502 and 0715 build date.

GTS changes the variant and signature.

There's also a couple variants I hadn't noticed before:
F80/F82/F83_rep (repaired?)
F87CS
Hmm...

Also: I was apparently confused about the M2 sharing the GTS settings. Might've been confusion with another ECU, or maybe it's because my car is in a newer I-STEP than the many recent targets I've had.

When I changed it in ESYS, it said F87 and somethingGTS on the same werte.

Where did you see F87CS? Could be something new in a newer data. I'm on 58.3.

Edit: Seems I set mine to F87, which matched your F87 / GTS werte of 04.

[packetpilot]

Originally Posted by terahertz

When I changed it in ESYS, it said F87 and somethingGTS on the same werte.

Where did you see F87CS? Could be something new in a newer data. I'm on 58.3.

Edit: Seems I set mine to F87, which matched your F87 / GTS werte of 04.

I'm on 60.1 I believe; my I-STEP is definitely accurate and is 16_11_502.

They're in Variantencodierung_Normal, the new fields. I failed to capture a screenshot, and can't right now due to bedtime. Sometime soon I should be able to, unless someone beats me to it.

This is why I VO code--it's the inbuilt 'cheat code' mechanism after all (albeit a sledgehammer sometimes that warrants honing).

Opening post has been updated with version logic disclaimer.

[terahertz]

Originally Posted by packetpilot

I'm on 60.1 I believe; my I-STEP is definitely accurate and is 16_11_502.

They're in Variantencodierung_Normal, the new fields. I failed to capture a screenshot, and can't right now due to bedtime. Sometime soon I should be able to, unless someone beats me to it.

This is why I VO code--it's the inbuilt 'cheat code' mechanism after all (albeit a sledgehammer sometimes that warrants honing).

Opening post has been updated with version logic disclaimer.

VO coding wouldn't help me here. My software is from before the GTS "existed".

People had the same issues with ZCP coding back then. Had to update the car to at least 58.0. I don't know what would have happened if you VO coded it. I assume it wouldn't actually change anything since if you forced the values anyways it caused errors. I tried coding ZCP VDC back then before I updated to 58.3 and the VDC module was stuck on full stiff with a chassis error. ISTA couldn't fix it.

I'm guessing maybe the FA would be invalid too, since the model type and/or salapa things didn't exist yet. If you can't activate the FA, you can't VO code, or code at all.

[packetpilot]

Here's some evidence this is (somewhat) breaking. Same holds true replacing F87CS with F80/F82/F83_rep.

[terahertz]

F87CS is known. It's the new M2 CS that is making the rounds in mule form. If my software was new enough I'd try it.

[packetpilot]

Originally Posted by terahertz

F87CS is known. It's the new M2 CS that is making the rounds in mule form. If my software was new enough I'd try it.

I know the car itself is known; I haven't seen anything about EPS coding specifically, is what I mean.

'pologies for being vague.

[terahertz]

Ah okay. I think eps coding is pretty new because there wasn't any other option a year ago. Now there's gts, m2, m2cs

[packetpilot]

Originally Posted by terahertz

Ah okay. I think eps coding is pretty new because there wasn't any other option a year ago. Now there's gts, m2, m2cs

And the much more curious F80/F82/F83_rep. That'd be more relevant to understand for us.

[packetpilot]

Originally Posted by terahertz

VO coding wouldn't help me here. My software is from before the GTS "existed".

I get that, but what I was trying to convey is more along the lines of the reason why I hadn't realized until last night that there have been two unnoticed variants sitting there for months (when I last updated my I-STEP).

[packetpilot]

Here's the screenshot.

[packetpilot]

Feedback from a ZCP customer who went to GTS EPS (58.3):

I drove the car for about an hour after coding. The first thing I noticed was steering became ligter for all the modes (comfort/sport/sport+). I always used Comfort steering when I had the stock ZCP steering since it provided me the most feedback. The comfort mode on M2/GTS steering is noticably lighter and in fact here is my assessment:

Comfort ZCP = Sport M2/GTS
Sport ZCP = Sport+ M2/GTS

I haven't noticed any improvements on steering feedback (but I'm no expert on this area lol). I didn't have any dead spot issues so it still feels the same for me. I'm still not sure if I like the lighter steering or not lol. I guess I will drive the car for a while like this and decide

The changes regarding near-center damping seem more noticable to non-ZCP drivers, although the ZCP sample size for me is this sole car at the moment, since EPS coding seems to be an emerging arena.

[packetpilot]

My own feedback going from GTS on 60.1 to F87CS:

Spent two hours driving, mostly highway. Changes seem for now (without any spirited driving whatsoever) to be around weight/resistance.

The F87CS settings seem to be a notch lighter, between sport and comfort modes anyway. Hardly spent more than 30sec in sport+ steering mode.

[packet.pilot]

A data point (wait, should it be datum point? nah that sounds silly) uncovered yesterday:

Working on a 2017 ZCP, and converting EPS to F82GTS didn't bring about much of a change. "Noticeable, but negligible" are the exact words from the owner.

Changing from F82GTS to F87CS brought about a much more noticeable change.

To reiterate what was stated earlier, ZCP cars already seem to have the 'dead spot near center' eliminated, or at least the MY2017 cars.

[cookiesowns]

I coded F87CS on my F87 M2 and there's a noticeable difference, not sure if it's for the better or not, but the steering feels "tighter" as if the on-center feel is more accurate. has a little bit more feedback too, it could also be placebo as well.

Will try F82GTS on the M2 to see if there's any difference, as well as update to the latest ISTEP.

[drinnird1]

is there a list of values to change to code the EPS to GTS?