UPDATE: M3 CS on KW Suspension HAS

[chrispraeger]

Originally Posted by CanAutM3

When you say “approved”, I assume you mean TÜV approval?

...I preferred to go the MP-HAS route to maintain the same the spring rates for an optimal pairing with the damper calibration...

Yes, I mean the TÜV approval.
And just an addition: when you are putting a HAS Kit - no matter what - in the CS, your dampers will not work in an optimal range.
I talked to Tom Schirmer and he said, that in the worst case, the bottom side of your damper can be damaged during a trackday for example.
A HAS Kit ist only a compromise - I will go with a KW Clubsport 3way next year.

Originally Posted by CanAutM3

No, definitely no spacers. I don't like what they do to the suspension tuning, particularly on the front wheels.

Especially with your setup and the camber plates, I would recommend spacer in the front.
You will get a much better handling - give it a try.

[tom @ eas]

Looks fantastic, great work.

[shay2nak]

Are the spring rates of the M3 CS the same as ZCP? The rest is just coding, AFAIK.

[shay2nak]

Originally Posted by CanAutM3

Just got this pic from my dealer. MP-HAS installed, going for alignment next

That's pretty damn low enough for MP HAS. Is that lowered all the way at the front?

[CanAutM3]

Originally Posted by chrispraeger

Yes, I mean the TÜV approval.
And just an addition: when you are putting a HAS Kit - no matter what - in the CS, your dampers will not work in an optimal range.
I talked to Tom Schirmer and he said, that in the worst case, the bottom side of your damper can be damaged during a trackday for example.
A HAS Kit ist only a compromise - I will go with a KW Clubsport 3way next year.

My understanding is that the EDC programming is made to adapt to the lower ride height offered by the HAS. Hence why older cars needs to have their EDC module reprogrammed when installing the MP-HAS kit.

Originally Posted by chrispraeger

Especially with your setup and the camber plates, I would recommend spacer in the front.
You will get a much better handling - give it a try.

What makes you say that? I am interested in your point of view on this.

I've got spacers of varying thickness at home, so it easy for me to try out. However, altering the offset on the front axle changes the scrub radius and required Ackerman angle when the wheels are steered which i find kills steering feel and feedback. At least that was my experience on my E92 M3 and my previous F82 M4. Further, I doubt the small increase in track improves the handling that much.

[Miko M]

Looks perfect, love the color too!!!

[chrispraeger]

Originally Posted by CanAutM3

My understanding is that the EDC programming is made to adapt to the lower ride height offered by the HAS. Hence why older cars needs to have their EDC module reprogrammed when installing the MP-HAS kit.

What makes you say that? I am interested in your point of view on this.

I've got spacers of varying thickness at home, so it easy for me to try out. However, altering the offset on the front axle changes the scrub radius and required Ackerman angle when the wheels are steered which i find kills steering feel and feedback. At least that was my experience on my E92 M3 and my previous F82 M4. Further, I doubt the small increase in track improves the handling that much.

First: there will be no reprogramming of your EDC anymore.
But your dampers will definitely not work in their optimal range anymore.
You can only solve this issue with a complete coilover kit.

When you're altering the offset in the front you will have a much better and quicker reaction in corners - especially because you are running more camber.
I really can't understand why spacers should be bad.
Even on the track, we are using various types of spacers for one car and different setups.
But of course, it is all about your feeling for your car.
Maybe you can just give it a try with only 10mm in the front in the next weeks.

[CanAutM3]

Originally Posted by chrispraeger

First: there will be no reprogramming of your EDC anymore.
But your dampers will definitely not work in their optimal range anymore.
You can only solve this issue with a complete coilover kit.

When you're altering the offset in the front you will have a much better and quicker reaction in corners - especially because you are running more camber.
I really can't understand why spacers should be bad.
Even on the track, we are using various types of spacers for one car and different setups.
But of course, it is all about your feeling for your car.
Maybe you can just give it a try with only 10mm in the front in the next weeks.

Agreed, there is no need to reprogram the EDC on the CS because the latest software version has the lowering adaptability already programmed into it. Only older cars need to be reprogrammed. At least that is my understanding from what I've read.

I don't see how the dampers are not "working in their optimal range". If the spring rate in un-altered, the spring-damping pairing remains ideally matched.

As for spacers, when reducing wheel offset relative to stock there are several thing that happen. Stsrting with the benefit, reducing wheel offset increases track, which reduces weight transfer during cornering and results in improved grip. But, it is also why it is tricky to change the front and rear tracks by different amounts as it will alter the over/understeer behavior of the car.

One drawback is that by changing the wheel position relative to the suspension alters the how much the spring and dampers move relative to the wheel which affects overall suspension tuning. Another is that it alters the thrust load on the wheel bearings which results in increased wear. And last, which is the biggest drawback for me, is the effect on steering. First, it affects the scrub radius, which is the distance between where the virtual line of the strut axis meets the ground and the tire's contact patch centerline. This distance has an important effect on the forces that are communicated back in the steering. It takes only a few mm of change here to have a noticeable impact. Second, changing wheel offset also alters the required Ackerman angle. When the car turns, the outside wheel covers a greater arc than the inside wheel, hence the inside wheel needs to be steered more. This is factored in the design of the steering and suspension geometry. When changing offset, the Ackerman angle geometry is upset resulting in one of the wheels not pointing on the right path and scrubbing, reducing grip and scrubbing speed in the process.

[knightarmor]

Late to post to this but your M3CS looks awesome!

[Megabass]

So is it being debated that the MP HAS negatively affects handling? I'm just getting ready to fit a set of MP HAS on my CS.

[CanAutM3]

Originally Posted by Megabass

So is it being debated that the MP HAS negatively affects handling? I'm just getting ready to fit a set of MP HAS on my CS.

MP-HAS improves handling mainly from improved grip. A lower center of gravity reduces weight transfer during cornering and braking which improves total grip.

[Matt@AUTOcouture]

Love it, so pretty.

[eRiggs5]

Looks great. I did the same thing as well.

[Megabass]

Originally Posted by CanAutM3

When you say "approved", I assume you mean TÜV approval?

Good point about the height adjustment range. I preferred to go the MP-HAS route to maintain the same the spring ratesfor an optimal pairing with the damper calibration. Apparently BMW made a lot of efforts tuning the CS suspension, I wanted to tinker with it as little as possible.

You have an M3cs? So the mp has kit spring rates are the same as stock? Didn't know that, makes sense as to why the dampeners aren't adversely effected.

[CanAutM3]

Originally Posted by Megabass

You have an M3cs? So the mp has kit spring rates are the same as stock? Didn't know that, makes sense as to why the dampeners aren't adversely effected.

An M4cs actually.

The rumour has it that they have similar rates. The MP-HAS are progressive while the stock springs are linear, so they cannot be exactly the same though.

[Megabass]

@CanAutM3 lots of M3cs owners seem to use the kit without issue. I guess I'm second guessing the decision to have it installed on my car. I did already order parts though. :

Thanks dude, appreciate the input.

[clubcsl]

Originally Posted by chrispraeger

First: there will be no reprogramming of your EDC anymore.
But your dampers will definitely not work in their optimal range anymore.
You can only solve this issue with a complete coilover kit.

Do we know what spring rate are the OEM CS springs and what the KW ones ?

Thanks !

[clubcsl]

Anyone ?
A bit surprised about this.

[Maitre_Absolut]

Originally Posted by clubcsl

Anyone ?
A bit surprised about this.

you do know there are specific forum sections even one called "Suspension | Brakes | Chassis" ? Right now you are thread-jacking a members 3 yr old post about his car. Which I don't believe he even owns anymore.