Going from ZCP to CS edc!

[matty088]

Originally Posted by Lappy

I'm not doubting your impressions. I am just trying to rationally think why BMW would make the M4 CS softer. Going stiffer on the CS springs, would explain the need to turn the shocks up and go with less front bar. Going softer on the springs would explain nothing, especially while going to a softer bar on stickier tires. It just seems backwards to me.

At this point I wouldn't rule out misinformation of what the CS really is from the shock/spring/bar standpoint compared to the comp pack.

I think its more about the sum of the parts as oppose to any single part itself. I think if you change one you have to change them all for it to be proper. I liked the zcp suspension better before. If i lived in the city i wouldnt think that way.

I am surprised there isnt a finite answer on this. Anyone could check a parts schematic for matching part numbers. I guess the interest isnt really there to do the work

[matty088]

the ride was 1000% certainly harsher before. I dont think anyone could disagree on that. Harsher might be better if u have great roads.

I think bmw engineers tried to make the zcp very aggressive bc reviews kinda sucked for the base. I think they could have overshot for road use. Hence the weighting in the steering wheel being detuned (for the gts and cs models). I could see the suspension being detuned as well. In fact in my opinion i think it was.


I wanted to get other first hand opinions before i finally made a decision to go back. that was the purpose of this thread

[CanAutM3]

Originally Posted by matty088

I am surprised there isnt a finite answer on this. Anyone could check a parts schematic for matching part numbers. I guess the interest isnt really there to do the work

The challenge is that spring PN number tables are not readily available.

What we do know for certain that the CS uses the base front sway bar and the comp pack rear sway bar.

[Racer20]

Originally Posted by CanAutM3

I'm confused. I think your original post is indeed correct. When converting a CP to CS it is indeed the front swaybar that needs to be changed along with the springs. What am I missing ?

You're right. My original post was correct, and I edited my reply to reflect that. I didn't read closely enough.

[Racer20]

Originally Posted by CanAutM3

The challenge is that spring PN number tables are not readily available.

What we do know for certain that the CS uses the base front sway bar and the comp pack rear sway bar.

If CS owners could post their vehicle configurations (M3/M4 and options) and spring part numbers, I could take a crack at figuring it out more conclusively using the spring tables on ETK. VIN's would help too.

[CanAutM3]

Originally Posted by Lappy

Why would BMW make the CS suspension softer on a car that comes with cup2s?

Why?

Stiffer does not necessarily mean better performance. In general terms softer translates to more grip while stiffer translates to better response. So it is a question of achieving the optimal compromise for a given context.

In the end, it is all bout how all the chassis components work in harmony to achieve the desired result.

[A47]

[QUOTE=Racer20;24689527]Edited reply:
That's correct, the CS uses the base front bar, which is of a smaller diameter than the ZCP front bar. That's consistent with what I wrote above, no? I don't understand what you're saying here . . .

You said originally a front bar and 'a set of springs'.My understanding was just the front bar.Is that not right?
Thanks

[CanAutM3]

Originally Posted by A47

You said originally a front bar and 'a set of springs'.My understanding was just the front bar.Is that not right?
Thanks

That remains the question that needs to be answered.

As I posted previously, it is not an easy one to answer because the BMW spring PN reference table is not readily available. At some point, a forum member that had access to the tables posted that the M4cs shares the same springs as the M4 with competition pack while the M3cs shares the same springs as the base M3 (link). That is the only insight that is known, but it ultimately still remains to be confirmed. It is why many speculate the the M3cs has softer springs than the competition pack. So based on that assumption, to convert a M3CP to M3CS, one needs to swap the springs and front swaybar.

[Arcades]

Originally Posted by CanAutM3

That remains the question that needs to be answered.

As I posted previously, it is not an easy one to answer because the BMW spring PN reference table is not readily available. At some point, a forum member that had access to the tables posted that the M4cs shares the same springs as the M4 with competition pack while the M3cs shares the same springs as the base M3 (link). That is the only insight that is known, but it ultimately still remains to be confirmed. It is why many speculate the the M3cs has softer springs than the competition pack. So based on that assumption, to convert a M3CP to M3CS, one needs to swap the springs and front swaybar.

Random question CarAut, would you think upgrading front sway bar with aftermarket would worsen the ride or make it better if you have done something like KW DDC w/ CS EDC coding?

[CanAutM3]

Originally Posted by Arcades

Random question CarAut, would you think upgrading front sway bar with aftermarket would worsen the ride or make it better if you have done something like KW DDC w/ CS EDC coding?

I would say anything that stiffens the spring rates will worsen the ride comfort.

[Lappy]

Originally Posted by CanAutM3

Why?

Stiffer does not necessarily mean better performance. In general terms softer translates to more grip while stiffer translates to better response. So it is a question of achieving the optimal compromise for a given context.

In the end, it is all bout how all the chassis components work in harmony to achieve the desired result.

The comp pack is already a little soft IMO, making the CS even softer would be a step in the wrong direction. Look at any m3/m4/m2 that compete in autocross, first thing they do it slap a giant front bar on it. Bmw decided to not only go softer on the spring (unknown) and softer on the bar....on a car that has no camber on stickier tires and then claim it to be in between a comp and gts? Who knows, imo this is all speculation at this point, including if people are actually coding it correctly.

[CanAutM3]

Originally Posted by Lappy

The comp pack is already a little soft IMO, making the CS even softer would be a step in the wrong direction. Look at any m3/m4/m2 that compete in autocross, first thing they do it slap a giant front bar on it. Bmw decided to not only go softer on the spring (unknown) and softer on the bar....on a car that has no camber on stickier tires and then claim it to be in between a comp and gts? Who knows, imo this is all speculation at this point, including if people are actually coding it correctly.

I spend a fair bit of time at race tracks and I don’t know of anyone that “slapped a huge front bar” on an M2/3/4... this would make an F8X plow like hell.

I can attest that my M4cs has much better turn-in and better overall balance than my 2015 M4 did though.

Note that the claim of being slotted between the CP and GTS applies to the M4cs, not the M3cs (which is the one rumoured to be more softly sprung).

[matty088]

I think we need more people chiming in that made the shift. I am telling you. The cs codeing for EDC is not as firm as zcp. I drove the car into work today. Its definitely more kidney friendly over bumps. That's the MOST obvious first take away. But I am sorry.....around country backroads in the 30-60mph range the car is less tight. It feels less like a track car. It feels smoother.

Let someone tell me i am crazy or they agree. The technical side to this will be found in time. But for now the subjective feel to me is that this is NOT an upgrade if you prefer the most sporty feel. Its a comfort upgrade.

At very high speeds on the highway the car still feels awesome.

[Arcades]

I would say something considering I did code in CS EDC over my ZCP but considering that I have KW DDC suspension it kind of changes things.

[Racer20]

Originally Posted by matty088

I think we need more people chiming in that made the shift. I am telling you. The cs codeing for EDC is not as firm as zcp. I drove the car into work today. Its definitely more kidney friendly over bumps. That's the MOST obvious first take away. But I am sorry.....around country backroads in the 30-60mph range the car is less tight. It feels less like a track car. It feels smoother.

Let someone tell me i am crazy or they agree. The technical side to this will be found in time. But for now the subjective feel to me is that this is NOT an upgrade if you prefer the most sporty feel. Its a comfort upgrade.

At very high speeds on the highway the car still feels awesome.

1. It's very possible to achieve. It's better handling and better comfort than at least the base M3, and I suspect the ZCP as well.

This is because tuning shocks is really hard, and a system as complex as the M3's is never going to be truly optimized. Therefore a more skilled tuning engineer, a better algorithm, or better damper valve will typically be able to deliver improvements in both areas simply by applying what they have learned over 8 years of F8X development along with small improvements to the pets and software.

2. I agree that the CS EDC coding in and of itself is not an "upgrade" if not combined with the rest of the CS suspension. It's not intended to be. The dampers are the glue that holds the suspension together; each different suspension configuration needs a different glue to perform well. The glue for the CS simply isn't optimized to work well with the ZCP set up.

3. Regarding the CS being firmer or softer than the ZCP: it's both, at different times. Overall, the car has a more Porsche-like character, where you can always feel a bit of rebound keeping the car sucked down to the road, reminding you that it's a sports car. I don't notice anywhere on my car (base M3 with CS suspension) where there's obviously less damping, just areas where the damping is more properly optimized and gives the feeling of having more compliance.

Search my posts if you want more technical information about damping, ride and handling and EDC for base, CS, and ZCP. It's all there.

[OhioRiderAaron]

I believe I successfully coded the CS EDC, GHAS, and EPS on my 2016 ZCP. I haven't been driving this car much lately so take my comments with a grain of salt..

1. It seems like the ISTEP update made the biggest difference. Someone else would have to confirm what parameters changed from the older ISTEP to the newer one I got last week at the dealer, but it does seem like the rebound is better. I might even agree with the comment that it feels more PASM/Porsche-like. The dampening overall is not as good as a Porsche but it does feel less harsh compared to before the update. You get less small bumps translated to your body IMO.

2. New ISTEP ZCP vs CS, CS feels firmer in sport and sport+, and similar in comfort. You really would need to code back and forth to make a call on the comfort setting, or maybe my memory is just going to shit lol. I've got multiple track events within the next few weeks so I should be able to make a judgement whether theres any quantitative improvement from just the coding modification.

3. MDM may be be better on the newer ISTEP as well. I'm running at Mid Ohio this weekend so I should be able to provide an update on how intrusive it is compared to Euro MDM.

[matty088]

Originally Posted by OhioRiderAaron

I believe I successfully coded the CS EDC, GHAS, and EPS on my 2016 ZCP. I haven't been driving this car much lately so take my comments with a grain of salt..

1. It seems like the ISTEP update made the biggest difference. Someone else would have to confirm what parameters changed from the older ISTEP to the newer one I got last week at the dealer, but it does seem like the rebound is better. I might even agree with the comment that it feels more PASM/Porsche-like. The dampening overall is not as good as a Porsche but it does feel less harsh compared to before the update. You get less small bumps translated to your body IMO.

2. New ISTEP ZCP vs CS, CS feels firmer in sport and sport+, and similar in comfort. You really would need to code back and forth to make a call on the comfort setting, or maybe my memory is just going to shit lol. I've got multiple track events within the next few weeks so I should be able to make a judgement whether theres any quantitative improvement from just the coding modification.

3. MDM may be be better on the newer ISTEP as well. I'm running at Mid Ohio this weekend so I should be able to provide an update on how intrusive it is compared to Euro MDM.

Ty for feedback. Look forward to hearing more.

[Gio72]

I own a 2017 M4 not ZCP, but with 666 20 wheel and I coded EDC with ZCP setting, but, most of all, I coded MDM with the less intrusive CS setup: it feels fantastic!
Both MDM stock and ZCP are very intrusive and unusefull for me, because they behave very similar to full DSC ON mode: they push you to shift to DSC Off to have fun. CS MDM is very different indeed, because it allows a moderate and awsome powerslide!

[hellokitty]

After a bit of time playing with Thor,

I like the GTS DCT flash with CS steering, CS diff and CS MDM.

Aggressive shifts with little to no traction control intrusion.

This is on the latest iStep as of April 2019 on my 2017 ZCP.

[OhioRiderAaron]

Originally Posted by hellokitty

After a bit of time playing with Thor,

I like the GTS DCT flash with CS steering, CS diff and CS MDM.

Aggressive shifts with little to no traction control intrusion.

This is on the latest iStep as of April 2019 on my 2017 ZCP.

Only got a few sessions in today at Mid Ohio, but yes the latest ISTEP setting for MDM is way way better. The stock 2016 MDM and Euro MDM (coded in 2016) was not good at all in comparison, light flashing all the time too. I'm not sure if I just have the latest US MDM or CS MDM at the moment, but either way it actually allows you to get on the throttle now!

[hellokitty]

Originally Posted by OhioRiderAaron

Only got a few sessions in today at Mid Ohio, but yes the latest ISTEP setting for MDM is way way better. The stock 2016 MDM and Euro MDM (coded in 2016) was not good at all in comparison, light flashing all the time too. I'm not sure if I just have the latest US MDM or CS MDM at the moment, but either way it actually allows you to get on the throttle now!

I agree. The GTS settings have been surpassed by the CS coding in my opinion except for DCT.

I can mash it in 1st gear with MDM and have no power cut off. Fantastic.

I'm still on the fence about EDC on the latest istep ZCP VS CS though. Maybe I'll flash the CS EDC and see how it compares.

[OhioRiderAaron]

Originally Posted by hellokitty

I agree. The GTS settings have been surpassed by the CS coding in my opinion except for DCT.

I can mash it in 1st gear with MDM and have no power cut off. Fantastic.

I'm still on the fence about EDC on the latest istep ZCP VS CS though. Maybe I'll flash the CS EDC and see how it compares.

If I had the opportunity I would like to try flashing GTS back to CS DCT to compare, haven't tried the CS yet.

I could be wrong on the I+ ZCP vs CS EDC, esp. without coding back and forth. It's hard to be objective without some form of more-scientific judgement.