M3/M4 CS Owners Thread

[RugbyBro]

It seems that currently there is not an active CS owners thread, as such, I'm starting one here. Shout out to slcook54 for inspiring this and IB M for always looking out for CSs.

As many CS are coming on the market and appreciation for the CS name plate builds with each release by BMW, I expect that we will see many new faces amongst the ownership group. Hopefully this will serve as a great place for current owners, as well as past and prospective owners can hang out, discuss CS related topics, and learn more about these amazing machines.

So what is a CS?

In my opinion, it is the best version of F8X that you could have bought from the factory. It is the culmination of all the learnings of each iteration of F8X. Most of us know that initially, F8X was not necessarily well received by all... it was a lot of firsts for BMW: turbos, torquey power delivery, EPS, a rather unique sound, and higher limits than ever before. It's not secret that BMW further refined F8X's driving characteristics across all F8X over its model run: smoothing out the power curve, adjusting DCT characteristics, tweaking the diff, tweaking the damper tuning, tweaking the steering response, etc. all delivered thru firmware updates over F8X's model life. Through all of these learnings, as well as the learnings from M4 GTS - BMW created the CS: a full realization of the F8X chassis/platform.

So what is it not?

It is NOT a mystery anymore. We know now what makes a CS different from a regular F8X. It functionally shares the majority of components with the regular cars and doesn't necessarily have its own proprietary components outside of the aero pieces. In the spirit of what I mention above - BMW learning from each iteration of F8X - the CS is quite literally a parts bin car made up components that span the entire F8X range. Look no further than the suspension setup as an example: it is a mix of ZCP AND Non-ZCP hardware - the combination of which allowed BMW to finally tune the dampers correctly (IMO) and implement the desired front end characteristics (even better turn-in response). The CS is only so good because the regular cars were very good to begin with and only needed some key tuning to really unlock the potential of stock hardware. There has historically been some friction between CS and Non-CS owners due to the mystery of CS and the differing views on sharing the same components. There no longer needs to be any friction We know what these cars are now. Are they significant improvements? Absolutely. Are they ground shaking changes? No, no they are not. No kool aid needs to be served or ingested here.

So what's different:

M3/M4CS
- Engine tune - ~454hp / ~440lbft and improved power delivery
- GTS Oil Pan - 7.0L oil vs 6.5L on the regular cars
- DCT tune - CS specific
- Differential tune - Don't know if it's CS specific, will updated if I find out
- Steering tune - GTS steering
- Recalibrated DSC & ABS
- Suspension - significantly improved damping tune and slight differences between M3 & M4 hardware but generally it is: F: Non-ZCP springs (M3) and ZCP springs (M4), Non-ZCP sway, ZCP dampers. R: Non-ZCP springs (M3) and ZCP springs (M4), ZCP sway, ZCP dampers.
- CS specific lip spoiler and rear deck-lid spoiler
- M performance diffuser
- GTS hood - in combination with the CS lip increases front end downforce
- GTS center console delete
- Custom CS embroidered trim
- 763M wheels - PSS if you are US, Cup2s most everywhere else
- More basic BMW AC unit
- No comfort access - this is a strange one because you would imagine that the CA module wouldn't significantly add to the weight of an already heavy car (35XXlbs - 36XXlbs). However, the CA module actually lives in the center console assembly. The GTS center console delete is not just shave off of the center console, but an entirely different trim piece with no compartment for the CA module.
- SMB, AW, and BSM as a standard paint options, and the introduction of LRG and FDB as BMW colors
- CS muffler - ZCP muffler with CS specific welded tips

M3CS specific
- Re-purprosed Silverstone Jahre 30 interior
- No rear AC
- Shadowline tail lights

M4CS specific
- GTS tail lights
- GTS front seats (non-buckets)
- GTS door cards
- Melbourne Red as a paint option
- More basic radio head unit (no ASD)

So why did I choose a CS?

Simple - I wanted an out of the box car that would do everything my modded F82 would do but better. I spent some time in a CS, and after that, I was sold. To me the BIGGEST difference is in the suspension - it's amazing how much a proper damping tune (with related setup) can do. Much more confident, much better contact to the ground, and most surprisingly... much more comfortable. Seriously, CS damping is a very popular "mod" amongst ZCP owners (since they have the correct dampers).

I'm looking forward to having fellow CS owners get connected here and hearing about all of your experiences with these cars!

And of course, please enjoy this gratuitous rear end shot of my car.

[slcook54]

Thanks for starting the thread Alex, will follow up with some additional thoughts.

In the mean time, this has been my favorite video to date

[CSBM5]

Re comfort access -- the CS does in fact have CA for locating the key inside the car, right? Unlike the E9x generation which had a physical slot to insert the key fob on non-CA cars, the F8x does not have such. Hence does it not have a version of CA and internal antenna(s) to sense the key within the vehicle? I understand there are no CA door handles and likely no additional antennas (i.e. trunk access).

[CanAutM3]

The CS also have recalibrated ABS and DSC systems to better take advantage of R-comp tires. The ABS programming is a further development of the GTS one. AM&S found in their testing the CS stops in a significantly shorter distance than the GTS. I personally found the MDM of the CS to be significantly better than even the EU MDM I had coded on my previous M4.

You are right in saying the impact of the changes to the CS are significant, making the CS a much better track car. The whole car was tuned to better take advantage of sticky R-comp tires. I was 2.5 sec/lap faster with my CS than I was with my 2015 M4 at my local track (~1:50 lap), and that is on the same wheels and tires (APEX EC7 shod with NT01). That is a massive difference. Heck, I beat my previous best lap by 2 seconds on the first day I had my M4cs on track. Those changes also made the M4cs feel much more connected and dynamic at more sedate daily driving speeds, significantly enhancing the driving experience. I daily drove the CS on the star spec PSC2, which I find made the car whole and more cohesive.

Regarding suspension, there is a difference between the M4cs and M3cs, where the M4cs uses the Competition pack springs while the M3cs uses the bases spring, making the M4cs more stiffly sprung than the M3cs. Not quite sure why BMW did that though.

The M4cs also had a hybrid sound system with less speakers that shaved a few more lbs and still sounded fairly decent.

The single zone HVAC system shaves a fair bit of weight from the reduced ducting and dampers. And as a tidbit about the rear HVAC, while the center console vents are removed, there is still is HVAC an fed to the rear compartment footwell from under the front seats.

The hood serves 3 purposes: front downforce, reduced weight and improved cooling.

For my part, I really appreciated the center armrest removal and reduced door armrest for the increased elbow room it provided when driving on track. I really realized it when I took a student’s M3CP out for a few laps that almost felt claustrophobic in comparison.

As another tidbit, Melbourne red was only introduced for 2020MY replacing black in the standard M4cs colour palette. IMO, LRG is the colour to have because it is the only exclusive colour to the CS. SMB was made a standard colour (replacing SS2) and FDB was made available as an “Individual” option on the base M4 for 2020MY.

The M3/4cs were often misunderstood. They were clearly not intended for everyone. But for those that they appeal to, it is one fantastic car. It is by far the best ///M car I’ve ever owned.

[CanAutM3]

I’ll quote here something I posted a while back that might be of interest:

Originally Posted by CanAutM3

It's funny how every thread on the the CS turns into how those who don't have one say it's not worth it and those that do say it is .

I'll try not to fall into that trap by simply saying that it depends what you are looking for. BMW are starting to offer more levels of flavour to each of the ///M line-ups with the different trim levels. According to BMW own press material:

• Base=Daily use + Racetrack
• Competition= Daily use + Racetrack with enhanced performance
• CS= Racetrack optimized + daily use
• CSL(GTS)= Born for the Racetrack but still street legal (to drive to and from the track)

I think this sums it up pretty well .

You don't get the Competition Package "standard" with the CS, because the CS is another package altogether. What you do get with the CS package on the M4:

• Engine tune +28/+9hp vs Base/CP and +38lb-ft of torque
• Single walled welded on exhaust tips with ///M engraving (sound/cosmetics)
• CFRP driveshaft (drivetrain rigidity/weight reduction)
• CF front splitter (downforce)
• CF Gurney flap (downforce)
• CF hood (downforce, improved cooling, weight reduction)
• 763M wheels 19" front 20" rear (weight reduction)
• PSC2 tires 265/35R19 front 285/30R20 rear (improved grip, however PSS in the US )
• Recalibrated ABS, DSC, EPS, EDC, DCT and e-diff, optimized for R-comp tires
• Retuned suspension (CP springs and rear swaybar, base front swaybar -> reduced understeer)
• Increased top speed limiter
• Lightweight door cards with pull straps (weight reduction/reduced sound deadening)
• Alcantara steering wheel (improved grip)
• Seats with alcantara side bolsters (improved grip)
• Single zone HVAC (weight reduction)
• Center armrest deletion (improved elbow room/weight reduction)
• Headreasts with M stripes (cosmetics)
• Alcantara dashboard trim with CS engraving (cosmetics)
• CF rear diffuser (cosmetics)
• OLED tail lights (cosmetics)
• CS door sills (cosmetics)
• Exclusive Lime Rock Grey colour optional (cosmetics)

Now, from my own track rat perspective that wants to own a single fully warrantied car, the CS is a perfect fit for me. I daily my CS through all 4 seasons. I Drive it to work, to the store, take it on family outings/road trips with the wife and two kids, use it to haul material from the lumbar yard and more. Plus, it serves to fill my track addiction 20 to 25 days per year. So I guess I am the perfect target audience for the CS .

What I find makes the CS special from a performance standpoint is how small increments in every area, such as the suspension tuning, the increased power across the entire rev range, the lower weight, the improved aero and the retuned electronics (ABS, e-diff, EPS, DCT, EDC) optimized around track tires, have all been tuned to work in unison. The fact that I am 2 seconds faster at my local track compared to my previous M4 on the same tires is quite telling IMO. These improvement cannot be truly appreciated on a street only driven car. Further, elements such as the reduced sound deadening from the lighter door cards contribute to the overall driving experience. The CS still comes loaded with luxury and tech features. It is not that spartan. The lack of center armrest that so many complain about is a feature I actually appreciate as it provides improved elbow room to handle the steering on track. To me, the only slight annoyance, is the lack of comfort access. Having been pampered with such a feature for the previous 10 years, I still find myself tugging at a locked door handle on my CS even after 18 months of ownership. As for the power increases, it is much more substantial than the 9hp peak increase over the CP suggests. The power is increased over the entire rev range which results in close to 40hp gains at some RPM. The gain of accelerstion of the CS over the CP is greater than the gain of the CP over the base. See this thread for more details: https://f80.bimmerpost.com/forums/sh....php?t=1376759

That being said, the base and competition package still offer great performance while offering more standard and optional comfort/luxury/tech items than the CS, which can make them better daily drivers to some. For instance, many of the driving aids are not offered on the CS. It is however important to point out that the CS comes standard with many features thay are optional on the base or CP variants. Further, the composition of the CS' executive package is quite different than the one of the other M4s, so you'll need to look up the details.

Features that cannot be had on the M4cs:

• Comfort access
• Heated steering wheel
• Full leather doorcards
• Dual zone climate control
• Center armrest
• Rear Center console HVAC vents
• Surround view
• HK sound system
• Active blind spot detection
• Driving assistance (collision avoidance)
• Parking assistant (self parking)
• Sunroof
• Headlight washers (in Canada)
• Rear sunblind (Canada only)
• 6MT

[RugbyBro]

Originally Posted by CSBM5

Re comfort access -- the CS does in fact have CA for locating the key inside the car, right? Unlike the E9x generation which had a physical slot to insert the key fob on non-CA cars, the F8x does not have such. Hence does it not have a version of CA and internal antenna(s) to sense the key within the vehicle? I understand there are no CA door handles and likely no additional antennas (i.e. trunk access).

Yup it has keyless start but no keyless unlocking. They must be two different modules internally. I have seen that there are full CA retrofits available… I wonder if any CS owners have retrofitted this?

[Maitre_Absolut]

There is an active FB group for CS owners.

I still have my 3CS and was one of the first to get one in August 2018. Now at 28k km / 17k mi.

While I have put a deposit on an RS6, I am still very much looking forward to another summer with my M3. Maybe it will even convince me to keep it .

[RugbyBro]

Awesome thanks CanAutM3! Updated the OP with some of this info.

For any newer CS owners, CanAut is one of the more knowledgeable former CS owners on this board when it comes to the technical details and utilization of those details in the real world (especially track) - it’s great to have him contributing here

[slcook54]

Thanks again for the starting the thread Alex. I'm also hoping we can use this thread to talk through modifications and troubleshoot, given the CS differences compared to base and competition F80s.

This thread is confirming that something is off with my car. I picked up my CS a couple weeks ago and started my build journal here. I track my E92 1x per month and was excited to see what the CS offered out of the gate. I drove the car back from Seattle home to San Francisco and was honestly shocked how floaty the front-end felt. Texting with Alex, I believe this has something to do with the Dinan HAS kit that the previous owner installed. This is a generic F80 kit, not specific to the CS. Link here.

The description of the kit specifies that it increases the front stiffness by 50% and the rear by only 10%. Aside from the front-end being jarring over bumps, even in Comfort, I'm thinking this adjustment also messed with the F/R balance of the suspension. Taking corners even at 6/10th's, the traction light is going crazy, there is no front-end presence or connection to the road. The front-end is lifting significantly under throttle and inducing understeer.

The car came with mismatched tires, 255 PSS on the front and 285 Hankook Ventus Evo2 on the rear. The tread life looks fine. After reading some of the initial posts in this thread and better understanding that several of the systems were developed around the Cup2, I'll likely move to that tire to best replicate the factory intentions.

We also decided to remove the front splitter for the drive back, which could be contributing to a bit of missing down force. My plan will be to have my shop reinstall the lip, balance the wheels, align the car and reinstall the stock springs and see what is feels like after that.

[IB M]

Looking forward to this thread and all the content to follow.

One trivial and peculiar 3CS fact - the e brake handle is different from the 18 ZCP and appears to be the exact same as in my 13 E92 ZCP. Not sure why but interesting.

Anyone know if the M4CS e-brake handle is a E9x version or same as F82 ZCP?

[CanAutM3]

Originally Posted by slcook54

Thanks again for the starting the thread Alex. I'm also hoping we can use this thread to talk through modifications and troubleshoot, given the CS differences compared to base and competition F80s.

This thread is confirming that something is off with my car. I picked up my CS a couple weeks ago and started my build journal here. I track my E92 1x per month and was excited to see what the CS offered out of the gate. I drove the car back from Seattle home to San Francisco and was honestly shocked how floaty the front-end felt. Texting with Alex, I believe this has something to do with the Dinan HAS kit that the previous owner installed. This is a generic F80 kit, not specific to the CS. Link here.

The description of the kit specifies that it increases the front stiffness by 50% and the rear by only 10%. Aside from the front-end being jarring over bumps, even in Comfort, I'm thinking this adjustment also messed with the F/R balance of the suspension. Taking corners even at 6/10th's, the traction light is going crazy, there is no front-end presence or connection to the road. The front-end is lifting significantly under throttle and inducing understeer.

The car came with mismatched tires, 255 PSS on the front and 285 Hankook Ventus Evo2 on the rear. The tread life looks fine. After reading some of the initial posts in this thread and better understanding that several of the systems were developed around the Cup2, I'll likely move to that tire to best replicate the factory intentions.

We also decided to remove the front splitter for the drive back, which could be contributing to a bit of missing down force. My plan will be to have my shop reinstall the lip, balance the wheels, align the car and reinstall the stock springs and see what is feels like after that.

The CS suspension tuning was all about SOFTENING the front relative to the rear (through the sway bars) to reduce understeer. So the spring rates you mention would definitely increase the level of push.

I had the MP-HAS on my M4cs and just tinkering with the front and rear ride height also helped tune the balance of the car. I had originally set the front to a lower ride height, which reduce corner exit traction. Raising the front a tad eliminated the problem I had.

Suspension tuning is a fine art that is very difficult to master. It is so much easier to make things worse instead of improving them.

[M3CSinWisc]

Glad to see a CS owners thread here! I’ve owned mine since this past September, and it’s been parked for the winter since early November. The weather is just about right to break her out again.

Hate to be a bore, but aside from some minor coding, the car will remain bone stock. I had actually bought an AA EL Midpipe, but ended up returning it because I didn’t want to cut the stock exhaust. I know it’s nothing special (a ZCP w/ different welded tips), but the stock CS sound doesn’t bother me, aside from the burbles, which I intend on coding out.

The only thing which I have second thoughts on is not having a 6MT, and last month is almost traded in for an M2 Comp just to get that manual interaction. I’m holding tight on that for now though, really want more seat time before I make the final decision.

Anyways, love the car, can’t wait to take it out from the car cover here in the next few weeks!

[M3CSinWisc]

Originally Posted by slcook54

Thanks for starting the thread Alex, will follow up with some additional thoughts.

In the mean time, this has been my favorite video to date

This video is what inspired me to go for the CS. Would love the chance to thank the guy personally for a fantastic piece of videography.

[RugbyBro]

Originally Posted by M3CSinWisc

Glad to see a CS owners thread here! I’ve owned mine since this past September, and it’s been parked for the winter since early November. The weather is just about right to break her out again.

Hate to be a bore, but aside from some minor coding, the car will remain bone stock. I had actually bought an AA EL Midpipe, but ended up returning it because I didn’t want to cut the stock exhaust. I know it’s nothing special (a ZCP w/ different welded tips), but the stock CS sound doesn’t bother me, aside from the burbles, which I intend on coding out.

The only thing which I have second thoughts on is not having a 6MT, and last month is almost traded in for an M2 Comp just to get that manual interaction. I’m holding tight on that for now though, really want more seat time before I make the final decision.

Anyways, love the car, can’t wait to take it out from the car cover here in the next few weeks!

Nice! Need a pic to verify

Also, I’m on a EL setup but of the UEL setups I’ve heard, I actually liked the stock CS setup the best. I understand the desire to avoid cutting into the exhaust chain.

On the M2 - give it some time, they are having a moment right now but I wouldn’t forgo the CS while paying a premium for a M2. But at the end of the day you gotta go with what is going to make you the most whole, and if that’s a short wheel base 6MT then it is what it is. If you could trade into a 2CS in a reasonable deal, that would probably be the best move. The 2CS isn’t a mystery either (although there’s a lot of 2CS hype). The suspension is ripped directly from the F80/2 CS and has all the accompanying CS tunes (except engine, it has the ZCP tune there) but in a shorter wheelbase package. Literally a mini M4CS!

[M3cosmos95]

I'm just here for the gratuitous CS pictures... and maybe some info about my new car

Pics of mine stock and then with a few mods, I was wondering why I couldn't find a dedicated CS thread haha.

[RugbyBro]

Originally Posted by M3cosmos95

I'm just here for the gratuitous CS pictures... and maybe some info about my new car

Pics of mine stock and then with a few mods, I was wondering why I couldn't find a dedicated CS thread haha.

Very nice - I almost bought an AW CS but it slipped thru my hands. What have you got planned for it?

[M3cosmos95]

Originally Posted by RugbyBro

Very nice - I almost bought an AW CS but it slipped thru my hands. What have you got planned for it?

Thank you! Haha I got lucky with this one, found it had been sitting at a Maserati dealer for 3 months 8 miles from my house and I couldn't say no to the price! I'm a little jealous of yours, I love the lime rock gray!

Nothing too big planned, will be finishing the interior off with the matte cf shifter &trim/ebrake from the m2 competition. Then maybe an Active EL mid pipe. I personally think the cs comes pretty much perfect from the factory! I want to start doing autocross then maybe some track days, if I'm ever not working weekends lol.

Already done:
Dinan CF mirror caps
Paddle Shifterz matte carbon fiber paddles
M Performance matte carbon wheel trim
Autotecknic painted reflectors and satin red m1/2 buttons
BMC air filters with Carbon filters removed.

[IB M]

In for pics as well.

Mine has never seen rain.

SMB, CCBs, and Icon headlights with full PPF

[M3CSinWisc]

Only recent pic I have, she's still sleeping... will be taking her out on Wednesday, it's supposed to be in the mid-60s

[11LMBiSTT]

Nice to see a dedicated CS thread, since we're not cool enough for a dedicated sub forum.

Roll call... calling all CS's, post a pic of your whip...

Bella, checking in from sunny So Cal!

[jtskariah]

Don't have to tell me twice ��

Current Mod list:
-Akrapovic full titanium exhaust (evolution mid-pipe + muffler with stock downpipe)
-XPEL Front end Paint Protection Film (full hood, front fenders, number, front lip) - will do the rest of the car at a later date
-XPEL ceramic coating on full car
-IND Rear honeycomb reflector delete
-IND Black M4 CS badges
-IND polar blue engine start/stop button
-IND Euro Sun Visors (no warning stickers)
-BMW Euro side view mirrors (OEM Piece- no blind spot)
-IND Tri-color painted M performance carbon fiber shift knob (OEM Piece)
-IND painted driver keyhole delete
-M-performance carbon fiber shift knob Trim (OEM Piece)
-IND painted BMW roundels (chrome portion painted black for both hood and trunk)
-IND painted rotating hub caps (chrome portion of roundel painted black for all 4 wheels- OEM piece)
-M Performance carbon fiber gas cap cover (OEM piece- this one is extra lol)
-M performance metal pedals (OEM piece)
-LLumar Stratos 35% tint all windows (the windshield was tinted from the previous owner- unknown tint brand or darkness level- looks to be 50-60% but might redo this later)
-Blackvue 900x plus 2 channel dashcam with 124 external battery and blendmount
-Bimmercode coding for general features
-Eventuri carbon fiber seatbacks
-M Performance carbon fiber license plate (OEM piece)
-Carbon Fiber hood vent for M4 CS hood (custom made)
-Carbonex aluminum hood latch handle
-Amazon silver light switch trim surround piece (cheap but worth it)
-Gates Innovation custom M4 CS keyfob (painted Limerock gray to match the car color with backup key textured black - this is X5 key and higher quality than our standard M4 key)
-M4 CS intercooler cover (made out of metal by s55covers on Instagram)- my only current "cosmetic" engine mod

Mods for the future:
-BMW 6 piston gold calipers front 4 piston rear (from CCB kit- but will use M2 competition metal rotors instead of carbon-ceramic)
-M-performance HAS (debating on this because my current stock height has yet to scrape on anything... as soon as I lower the car I know this will be an issue)
-Future classic wheel spacers 10/12 (this is a maybe- love the current drive not sure if I want to mess with the stance)
-Alcantara Headliner (this is a maybe- this is a pricey mod but I think it would look great in our interior... nervous about taking out the headliner as well since I am unsure how much work it will require and don't want to mess anything up/cause rattles)
-M Performance carbon fiber mirror caps OEM (I am probably going to skip this- for some reason, the color-matched mirrors look amazing to me)
-M Performance carbon fiber side skirts OEM (I am a maybe on this one- cannot find these anywhere carbon fiber and OEM just a bunch of aftermarket solutions- also not sure how they will look in person once I fit them)

Future Engine bay mods (if I finish everything else and get bored- these are all just maybe's- the car is just great without these)
-Eventuri carbon fiber charge pipes
-Eventuri carbon fiber air intake V2
-Titanium dress up bolt kit (in gold)
-Carbon fiber engine cover (M performance or Eventuri)
-Blackline metal coolant tank cap (black)
-Blackline metal oil cap cover (black or gray)
-Weistec metal oil filter housing cap (black)

Engine tunes and other performance upgrades are last on the list. I am very happy with the car when it comes to performance so I doubt I will make any major changes. Because of that, I do not think I will be messing with the crank hub. Hopefully, stock tunes will keep me running strong for the next few years.
This is a large list of mods, but in my opinion, they are very mild and produce an OEM plus appearance. These cars already look amazing as is, I do not think we need to change very much for the appearance apart from some subtle upgrades here and there. The goal is to keep the spirit of the original car... hopefully this list exemplifies that.

[THEROK]

Hands down the M4 CS is the best looking M car of all time.

Per BMW tech documentation, the additional oil pick up and bigger oil sump capacity (mg) allows it to handle greater lateral and longitudinal Gs of up to 1.4g.

Great thread. Enjoy.