M3/M4 CS Owners Thread

[RugbyBro]

Originally Posted by CanAutM3

It's not a simple rebrand. The MP-HAS have distinct spring rates tuned, tested and optimized by BMW themselves. IMO, the MP-HAS are superior to the KW-HAS.

My use of “essentially” was probably not used correctly! Rebrand from the point of view that it’s the same hardware but different spring rates. Wasn’t trying to be too wordy in my post lol

[jmg]

Originally Posted by f80jruss

Looking to lower my m4cs on lowering springs… any suggestions ??

I ran with MPHAS for that height adjustability. Don't settle for just springs if you want it just right and corner balanced.

[slcook54]

Best place to buy MP HAS?

[slcook54]

Ordered Cup2 connects (240tw) last night.

265/35/19 & 285/30/20.

[jmg]

Originally Posted by slcook54

Best place to buy MP HAS?

Most dealers will price match getbmwparts.com since it's actually some dealership's (edit: Silver Springs BMW) parts website. You just have to ask

[Gtracer]

Originally Posted by slcook54

Ordered Cup2 connects (240tw) last night.

265/35/19 & 285/30/20.

Can't wait to get your feedback on those. I ALMOST pulled the trigger on them but couldn't get a set in my network.

[11LMBiSTT]

Originally Posted by slcook54

Best place to buy MP HAS?

BMW Parts Pros and Google search the part number. Also, saw one in the suspension classifieds for a good price.

Those new tires are gunna transform your car along with the MPHAS. GC Camber Plates are also great to pair with MPHAS.

[slcook54]

Originally Posted by Gtracer

Can't wait to get your feedback on those. I ALMOST pulled the trigger on them but couldn't get a set in my network.

Will report back and detail it in my build thread. I pick up the e92 next week and drop off the CS for the following:

- remove tint
- Remove CF front and rear bumper add-ons
- Remove Dinan suspension / install stock suspension
- install stock front lip
- Install iND painted reflectors
- Install iND Badge
- mount and balance Cup2
- alignment

[11LMBiSTT]

CS²

[dezzracer]

Originally Posted by RugbyBro

Very nice ride! One thing to consider is that with the CSs BMW made an effort to soften the frontend with less roll/sway stiffness to promote better turn-in, so you may want to maintain a similar relative front/rear stiffness when upgrading the sway bars while retaining stock dampers.

Agree. BMW engineers nailed the stock settings in the M3 CS. Other than doing a full on 20k race suspension swap it's hard to beat with just pads, brake fluid, camber plates and cup twos. Other than that leave the CS as is.

[CanAutM3]

Originally Posted by jmg

I ran with MPHAS for that height adjustability. Don't settle for just springs if you want it just right and corner balanced.

Agreed. And the adjustability goes well beyond aesthetics and corner balqncing. Having the ability to vary the relative front-to-rear roll center heights has direct effect on handling balance.

[M3CSinWisc]

So that front wheel gap: engineered that way for more suspension travel under braking for increased grip? Or, intentional so owners wouldn’t rip the front lip off leaving the dealership?

For myself, aesthetically that’s the only <very> small negative against this car, but it more than likely serves a purpose, so it isn’t something I’m going to even attempt to fix. Add to that, I’m lucky that I don’t scrape leaving my driveway in stock form, don’t want to push my luck.

[jmg]

Originally Posted by M3CSinWisc

So that front wheel gap: engineered that way for more suspension travel under braking for increased grip? Or, intentional so owners wouldn’t rip the front lip off leaving the dealership?

For myself, aesthetically that’s the only <very> small negative against this car, but it more than likely serves a purpose, so it isn’t something I’m going to even attempt to fix. Add to that, I’m lucky that I don’t scrape leaving my driveway in stock form, don’t want to push my luck.

The wheel gap doesn't make the car higher in front to clear driveways. It's the same ride height as in back, it's just the wheel well is literally bigger to allow for clearance of the wheel under braking.

Typically we lower the front more than the rear to make the wheel gap even. This actually gives the car a forward rake and affects the way the car handles, and not in a good way IMHO. One thing I have noticed is the lack of rear end stability under hard braking. I tuned this out by raising the front a little bit. You can also do this by adjusting compression in the front, rebound in the rear, or spring rates, but that is beyond the scope of lowering spring and a HAS setup. You would need a true coilover system for that.

[M3CSinWisc]

Originally Posted by jmg

The wheel gap doesn't make the car higher in front to clear driveways. It's the same ride height as in back, it's just the wheel well is literally bigger to allow for clearance of the wheel under braking.

Typically we lower the front more than the rear to make the wheel gap even. This actually gives the car a forward rake and affects the way the car handles, and not in a good way IMHO. One thing I have noticed is the lack of rear end stability under hard braking. I tuned this out by raising the front a little bit. You can also do this by adjusting compression in the front, rebound in the rear, or spring rates, but that is beyond the scope of lowering spring and a HAS setup. You would need a true coilover system for that.

Good stuff my post was mostly rhetorical, and I was mostly certain the gap was intentional for suspension travel (+ wheel clearance, as you pointed out). This suspension tuning stuff gets complicated really quick, I'd rather live with the gap than start messing around w/ engineered intent, but damn it if the perfectly spaced wheel/fenders don't make this car look perfect!

[RugbyBro]

Originally Posted by M3CSinWisc

Good stuff my post was mostly rhetorical, and I was mostly certain the gap was intentional for suspension travel (+ wheel clearance, as you pointed out). This suspension tuning stuff gets complicated really quick, I'd rather live with the gap than start messing around w/ engineered intent, but damn it if the perfectly spaced wheel/fenders don't make this car look perfect!

One thing that makes the front wheel gap look worse on the F80 specifically is the way the rear quarter panel / wheel arch is designed. It physically sits lower than a F82 quarter panel even tho both cars share the same chassis. That gives the impression that the rear is sitting lower on F80s when it is not, and the lower rear exacerbates the front gap visually. Look at the pic below - you’ll see that not only does F80 hang lower, but it’s also a bit taller than F82.

Edit: added 3 & 4CS pic for reference as well (re-upped for better optimized viewing)

[THEROK]

Originally Posted by M3CSinWisc

So that front wheel gap: engineered that way for more suspension travel under braking for increased grip? Or, intentional so owners wouldn't rip the front lip off leaving the dealership?

For myself, aesthetically that's the only <very> small negative against this car, but it more than likely serves a purpose, so it isn't something I'm going to even attempt to fix. Add to that, I'm lucky that I don't scrape leaving my driveway in stock form, don't want to push my luck.

You're chasing a solution that doesn't have a problem to begin with.

Bush league to adjust based on even front to rear, tire to fender gap. They shouldn't be even else dragster rake. There is no BMW M that comes from factory with even gaps all around.

If adjustable route, get it as level as possible based on side sill and make incremental adjustments from there by someone who knows wtf they're doing.

[jmg]

Originally Posted by THEROK

You're chasing a solution that doesn't have a problem to begin with.

Bush league to adjust based on even front to rear, tire to fender gap. They shouldn't be even else dragster rake. There is no BMW M that comes from factory with even gaps all around.

If adjustable route, get it as level as possible based on side sill and make incremental adjustments from there by someone who knows wtf they're doing.

It's a compromise between aesthetics and performance. Most street driven cars won't mind a bit of forward rake. Best bet is a corner balance with the driver at the wheel. Each corner is on a scale and ride hight is adjusted to balance weight to the driver's liking, ideally an even distribution, including left to right accounting for the driver's weight. It's a bit excessive for street cars, but if you are a stickler for performance and chasing 10ths of a second, it's pretty much the SOP.

[THEROK]

Originally Posted by jmg

It's a compromise between aesthetics and performance. Most street driven cars won't mind a bit of forward rake. Best bet is a corner balance with the driver at the wheel. Each corner is on a scale and ride hight is adjusted to balance weight to the driver's liking, ideally an even distribution, including left to right accounting for the driver's weight. It's a bit excessive for street cars, but if you are a stickler for performance and chasing 10ths of a second, it's pretty much the SOP.

It's looks like sht with dragster rake. And it's a street car full stop. Keep it level or stay stock.

[Nyc911]

Is anyone running wider tires in the rear on stock wheels or are 285 the widest you can go? I’m going to need new tires soon and wanted to know if I can go to 295 or even 305 in the rear

[M3CSinWisc]

Originally Posted by THEROK

You're chasing a solution that doesn't have a problem to begin with.

Bush league to adjust based on even front to rear, tire to fender gap. They shouldn't be even else dragster rake. There is no BMW M that comes from factory with even gaps all around.

If adjustable route, get it as level as possible based on side sill and make incremental adjustments from there by someone who knows wtf they're doing.

I'm not chasing a solution, nor do I think there is a problem I'm just intrigued by the engineering and design, it's resultant aesthetics, and how subsequently owners upset that original design by trying to "correct" those aesthetics. Been down that road myself with my previous car, never going to do it again. My CS will remain bone stock.

[THEROK]

Originally Posted by M3CSinWisc

I'm not chasing a solution, nor do I think there is a problem I'm just intrigued by the engineering and design, it's resultant aesthetics, and how subsequently owners upset that original design by trying to "correct" those aesthetics. Been down that road myself with my previous car, never going to do it again. My CS will remain bone stock.

What

[M3CSinWisc]

Originally Posted by THEROK

What

Not sure how that was hard to understand for you.. engineers have a gap on purpose, owners try to lower their car to get rid of it. We're in agreement, but whatever.