CS Suspension Specifics

[CanAutM3]

Originally Posted by Celestion

If you wanted a better-handling, faster, and more affordable car, you could opt for a non-ZCP F8x, get the Tractive suspension for ~$5k including install, and flash the CS tune for $700....

Is the CS really worth the extra $30k? I think not, given that you could get a base 992 (i.e. an actual sports cars) for only a little more... just trying to give you an alternative perspective.

It's different in Canada. The CS is only about $12k USD ($16k CAD) above a decently optioned CP (not even a fully loaded one). Since I track a fair bit, I want my cars fully warrantied. The 911 Carrera does not fulfill my practicality needs and, speccedd to my liking, is another $30k above the CS . If I were to get a 911, it would be GT3 and I would get a more sedate daily driver (I did consider this on more than one occasion).

[Wills2]

I'm on the record saying the M3/4 CS are over priced, but I would love an M3CS in LRG with MP HAS

Doesn't really matter about the cost, if you're getting one then you've over come that hurdle and what you'll be left with is one hell of a car.

A well specced 992.2 C2S is another 30k in the UK so that's probably not a great argument anymore as you can get 10k off either of the CS over here.

[Celestion]

Originally Posted by CanAutM3

It's different in Canada. The CS is only about $12k USD ($16k CAD) above a decently optioned CP (not even a fully loaded one). Since I track a fair bit, I want my cars fully warrantied. The 911 Carrera does not fulfill my practicality needs and, speccedd to my liking, is another $30k above the CS . If I were to get a 911, it would be GT3 and I would get a more sedate daily driver (I did consider this on more than one occasion).

Ahh, I see. I agree, it makes sense to get the CS given these considerations.

[spr]

So they're not adjustable like the BMW has? I thought it was just that kit with another edc flash. meh.

Originally Posted by Celestion

Here is a complete list of CS-specific suspension components:

• CS/ZCP w/DCT or Sunroof Front Spring - 31337857356
• CS/ZCP w/Sunroof Rear Spring - 33537857312
• CS/ZCP Front Damper Left - 31318008627
• CS/ZCP Front Damper Right - 31318008628
• CS/non-ZCP Front Sway - 31352284760
• CS/ZCP Rear Sway - 33557853266

All ZCP owners will need to buy a non-ZCP front sway bar. 6MT ZCP cars will need to buy CS front and rear springs, and DCT ZCP owners will only need to buy rear CS springs. Interestingly, ZCP cars with a sunroof already have CS springs, front and rear.

Non-ZCP owners with EDC will need to buy CS front and rear springs, ZCP front dampers, and a ZCP rear sway bar.

Source:
All part numbers are directly from the BMW part catalog.

To view the part catalog, use these logon credentials.
User name: eu111111
Password: bmwetk1

[SYT_Shadow]

Originally Posted by Celestion

If you wanted a better-handling, faster, and more affordable car, you could opt for a non-ZCP F8x, get the Tractive suspension for ~$5k including install, and flash the CS tune for $700....

Is the CS really worth the extra $30k? I think not, given that you could get a base 992 (i.e. an actual sports cars) for only a little more... just trying to give you an alternative perspective.

Definitely. CanAut, buy the real sports car that doesn't come with a LSD.


because real sports cars don't have LSDs!! Facepalm

[spr]

Mclaren's don't have lsd...

[Racer20]

Anyone have a similar list for the M3?

[TTR]

Better to buy KW CS 3 way

[Celestion]

Originally Posted by Racer20

Anyone have a similar list for the M3?

I updated my initial post to contain what could be the M3 CS part numbers.

[SYT_Shadow]

Originally Posted by spr

Mclaren's don't have lsd...

Correct. And they are built specifically to not have them. They are also pretty much the only real sports car to not have them.

The 991 series is not. All the real Porsches have LSDs. As soon as you upgrade out of a 100k amish edition 991 they all have LSDs.

Thank you for pointing out the equivalent of someone saying drinking nuclear sludge that has been nano filtered is perfectly ok for your health in a discussion about the perils of nuclear waste.

[Racer20]

Originally Posted by Celestion

I updated my initial post to contain what could be the M3 CS part numbers.

Interesting that the M3 springs are common with the base M3 (non-CP even!) while the M4 CS gets new springs.

One possibility is that the M4 CS doesn't actually get new retuned springs, it's just that the M4CS weight and weight distribution were different enough from the base car that the spring family had to be extended to accommodate the weight of the CS. In other words, the check load of the spring is different, but the rate and resulting ride frequency is the same.

Since the M3 is heavier than the M4 anyway, and the CS doesn't get all the weight savings goodies, the M3CS weight probably falls within the range of existing M3 and M4 variants, so springs already exist with the right check loads.

If this is true (a big if), then an M4 owner would be better off keeping his stock springs that were designed for his specific option configuration.

[Celestion]

Originally Posted by Racer20

One possibility is that the M4 CS doesn't actually get new retunedsprings, it's just that the M4CS weight and weight distribution were different enough from the base car that the spring family had to be extended to accommodate the weight of the CS. In other words, the check load of the spring is different, but the rate and resulting ride frequency is the same.

Interesting theory. Seems plausible to me.

[Bee Pee]

Is there any substance to sedan/coupe CS having ~ additional 0.5 deg negative camber upfront than lesser sedan/coupe F8X variants ?

If yes then what OE hardware is different/upgraded on CS to create added camber ??

[mechanic75]

Originally Posted by Bee Pee

Is there any substance to sedan/coupe CS having ~ additional 0.5 deg negative camber upfront than lesser sedan/coupe F8X variants ?

If yes then what OE hardware is different/upgraded on CS to create added camber ??

I’ve read this on a few road tests and just assumed it was incorrect. Thinking about it now they could have used different wheel carriers as they have them on the shelf. They are the ones used for camber correction and they are 0.5 degrees.

[Bee Pee]

Originally Posted by mechanic75

I’ve read this on a few road tests and just assumed it was incorrect. Thinking about it now they could have used different wheel carriers as they have them on the shelf. They are the ones used for camber correction and they are 0.5 degrees.

Yes - perhaps camber correction hub carriers is what's used on CP/CS models

I've retrofitted them on my m2 with mp coilovers - I'm running -2 deg upfront

[CanAutM3]

Originally Posted by Bee Pee

Yes - perhaps camber correction hub carriers is what's used on CP/CS models

I've retrofitted them on my m2 with mp coilovers - I'm running -2 deg upfront

CP M3/4 have the same front camber specs as the non-CP.

The GTS has 0.25deg more camber (at street height setting) than regular M3/4 due to the different and unique front hub carriers (to fit the coilover suspension) that also widens the front track. From what I gather in the GTS thread (and from my own experience with the F8X chassis), that is still not enough for track use and camber plates are still needed on the GTS for optimal tire wear.

I also doubt that the CS will have different front camber specifications that the CP and base M3/4 and will also need camber plates.

[mechanic75]

I just checked my chassis number (m3cs) and it shows the same part number as standard for the swivel bearings.

[PayamFSU]

So if you had an m3 and put m4 CS springs on it you could actually do a subtle drop on the car?

Also I have an 18 ZCP w CF roof and 6sp, so from the original post I would need just a front sway bar and which springs? The log in provided for the parts is no longer working ....

[Racer20]

Originally Posted by PayamFSU

So if you had an m3 and put m4 CS springs on it you could actually do a subtle drop on the car?

Also I have an 18 ZCP w CF roof and 6sp, so from the original post I would need just a front sway bar and which springs? The log in provided for the parts is no longer working ....

I converted my '15 6MT CF roof to the CS suspension + MP HAS. Rumor is that MP HAS kit is similar/same at ZCP, but I'm not sure how certain anybody is of that.

My advice would be to do the bar and the EDC coding with your stock springs. Most likely the car will balance out nicely with that setup. If not, try the base M3 springs or MP HAS kit.

[elisiX]

Will fitting the MP HAS to the M3 CS likely make the ride firmer?

Any idea how much firmer if this is indeed the case?

[CanAutM3]

Originally Posted by PayamFSU

So if you had an m3 and put m4 CS springs on it you could actually do a subtle drop on the car?

It's not straghtforward.

According to BMW specs, the total height of the M4cs (1392mm) is greater than the one of the standard M4 (1383mm). That can only be the result of a greater ride height due to the springs.

Now the resulting ride height depends on the spring rate, the spring height and the weight of the vehicle, so it's obvious to establish the resulting ride height of installing the M4cs springs on a heavier M3.

[Racer20]

Originally Posted by CanAutM3

It's not straghtforward.

According to BMW specs, the total height of the M4cs (1392mm) is greater than the one of the standard M4 (1383mm). That can only be the result of a greater ride height due to the springs.

Now the resulting ride height depends on the spring rate, the spring height and the weight of the vehicle, so it's obvious to establish the resulting ride height of installing the M4cs springs on a heavier M3.

The height difference could be due to the taller rear tire as well.