Lowering M3CS?

[Dean5]

Recently picked up an M3 CS from a fellow forum member a few weeks ago. Love the car, put on some minor exterior mods and an AA midpipe, but the fender gap is a bit too much for me. Has anyone here lowered their CS? I've heard KW HAS is a good option, but wanted to see what others had to say. [/IMG]

[F80NV]

Have heard a lot of great things on Swift Sport Springs and how well it works with the stock adaptive suspension. Considering getting a pair for myself.

[symple84]

I'm on KW HAS on my CS, zero issues.

[rborane]

Recognize that car wash. I’ll keep an eye out for you out there. Beautiful spec

[Dean5]

Originally Posted by symple84

I'm on KW HAS on my CS, zero issues.

Glad to hear. Probably going to go with that then, only have heard good things

[Dean5]

Originally Posted by rborane

Recognize that car wash. I’ll keep an eye out for you out there. Beautiful spec

Off of Thomas and 68th St!

[swagon]

Originally Posted by Dean5

Glad to hear. Probably going to go with that then, only have heard good things

Why not the M Performance HAS - it is made by KW for BMW to their own specs. I would trust this kit more than KW.

If you search a bit more, you will find people saying KW HAS and some other spring solutions deteriorate the ride after some time.

[jmg]

I went with MPHAS. For a few reasons:

1) Coils are expensive
2) I wanted to be able to fine tune ride height including forward rake
3) I wanted to be able to corner balance the car, which you can't do with just springs
4) OEM piece of mind

Loving them so far!

[Megabass]

Originally Posted by jmg

I went with MPHAS. For a few reasons:

1) Coils are expensive
2) I wanted to be able to fine tune ride height including forward rake
3) I wanted to be able to corner balance the car, which you can't do with just springs
4) OEM piece of mind

Loving them so far!

Pics? I'm highly considering the M Performance HAS as well.

[jmg]

Originally Posted by Megabass

Pics? I'm highly considering the M Performance HAS as well.

M3 CS Sunset by JMG, on Flickr

M3CS by JMG, on Flickr

This is with 265 tires and 12mm spacers up front and 295 tires and 5mm spacers in the rear. The 12mm up front rubbed at full lock, so I swapped for 10mm and it's all good now.

[spectromike]

have been reading through this post - do any of you track? Are the MPHAS and the GC Camber Plates good improvements for additional track prep? are you compromising anywhere by adding those parts?

[jmg]

Originally Posted by spectromike

have been reading through this post - do any of you track? Are the MPHAS and the GC Camber Plates good improvements for additional track prep? are you compromising anywhere by adding those parts?

I track 1-2 times a month when there isn't a pandemic going on! I don't do w2w, just HPDE's and autocrosses. For the money I think it's a great setup without going full track car. MPHAS is nice in that you can get a lower CG and still be able to corner balance without spending a lot of $ for full adjustability. If you want to retain factory like suspension tuning, it's hard to beat.

Camber plates are a must if you track often. Not only does it save your front tires, but it adds front grip on turn in and through the apex. More rear negative camber will help add grip during corner exit. I've noticed a 2-3 second improvement right away in my lap times with the same tires.

I've always lowered my cars, so the added ride harshness isn't a problem for me. My camber is set at -2.7. I have yet to do more than 3 track days with a proper pyrometer to see what the temps are through the patch. However, on the street there is definitely more tramlining. Imperfections in the road are more prominent. Some people may like this, as it kind of connects you to the road more through the steering wheel, but you do have to be more on your toes. Increased tire wear may also be an issue if you drive a lot. This isn't my daily so it's hard to say how much more wear I will get on the inside.

[mitch32]

I have zero experience with KW HAS or MPHAS but tons of experience in suspension! I'd go with MPHAS over the KW HAS just based on the fact that the dealer will give you less grief. KW is quality stuff on its own, the MPHAS is made by KW with BMW specifications which are either the same or more strict then KW (just a hunch). You can also get a spring to save money like emmanuelle design as they are basically original spring rates just shorter, I don't think you blow your shocks as I ran with even lower springs with 0 issues and many others have without issue. Only reason you would blow them if you literally bottom out the shock and that would take a massive pothole or something of that nature. Personally I'm on KW DDC and they are amazing literally blow your mind ridiculously comfortable with feel and stiffness but they are very $$$.

[Mintsopoulos]

Theres also the MSS kit, have you looked into that at all.

[rommeeeezy]

Originally Posted by jmg

M3 CS Sunset by JMG, on Flickr

M3CS by JMG, on Flickr

This is with 265 tires and 12mm spacers up front and 295 tires and 5mm spacers in the rear. The 12mm up front rubbed at full lock, so I swapped for 10mm and it's all good now.

Do you track your car with spacers? This is from another thread of mine, but figured I could ask you here.

Curious about getting spacers to push my rear fitment out a bit more while retaining most of the OEM driving characteristics.

[jmg]

Originally Posted by rommeeeezy

Do you track your car with spacers? This is from another thread of mine, but figured I could ask you here.

Curious about getting spacers to push my rear fitment out a bit more while retaining most of the OEM driving characteristics.

Yes, although I want to pull them off next time to see if there is any noticeable difference. Realistically, I don't think I'm at the skill level to tell the difference.

[Redline10000]

For those who track and have gone with lowering springs vs coils, have you noticed a reduction in the floaty feeling of the OEM suspension? Also has corner exit grip improved at all? Those are my two biggest problems.

[CanAutM3]

Originally Posted by rommeeeezy

Do you track your car with spacers? This is from another thread of mine, but figured I could ask you here.

Curious about getting spacers to push my rear fitment out a bit more while retaining most of the OEM driving characteristics.

If you change offsets differently front and rear you will NOT retain OEM driving characteristics.

[CanAutM3]

Originally Posted by Redline10000

For those who track and have gone with lowering springs vs coils, have you noticed a reduction in the floaty feeling of the OEM suspension? Also has corner exit grip improved at all? Those are my two biggest problems.

Maximizing corner exit speed is much more complex than just lowering springs. It is about optimizing the side-to-side weight transfer sharing between the front and rear axles. This can be achieved either through roll stiffness or roll center height adjustment of each axle.

That is one of the big benefit of going with a HAS system, because it allows you to fine tune the roll center height on each axle. For instance, the original height I had set on my car got me more oversteer than I wanted on corner exit. By raising the front, I was able to improve things significantly.

[Redline10000]

Originally Posted by CanAutM3

Maximizing corner exit speed is much more complex than just lowering springs. It is about optimizing the side-to-side weight transfer sharing between the front and rear axles. This can be achieved either through roll stiffness or roll center height adjustment of each axle.

That is one of the big benefit of going with a HAS system, because it allows you to fine tune the roll center height on each axle. For instance, the original height I had set on my car got me more oversteer than I wanted on corner exit. By raising the front, I was able to improve things significantly.

Thanks for the reply. I imagine the spring rates have a good impact here as well in increasing traction. My my question is mainly geared towards how well does the HAS increase driving dynamics at the track vs the bling of a lower stance which I care nothing about.

You bring up a god point about the ride hight adjusting the car balance. That is one point of concern as a HAS would mean playing with the rake to get the right balance.

[CanAutM3]

Originally Posted by Redline10000

Thanks for the reply. I imagine the spring rates have a good impact here as well in increasing traction. My my question is mainly geared towards how well does the HAS increase driving dynamics at the track vs the bling of a lower stance which I care nothing about.

You bring up a god point about the ride hight adjusting the car balance. That is one point of concern as a HAS would mean playing with the rake to get the right balance.

It is really how the entire suspension system works in unison. Suspension tuning is a very complex art and it is very easy to actually make things worse.

Lowering springs improve grip during cornering and braking through reduced weight transfer from a lower Cg, it's not only a question of "bling" and why race cars tend to sit lower than street cars. However, on our RWD cars, the reduced weight transfer from a lower suspension is not beneficial for straight line acceleration at speeds where the engine power can overcome tire grip (read stop light drag races).

Yes, spring rates definitely play a role with traction and grip. It's all about the desired trade-off: in general terms, a stiffer suspension (higher spring rates) reduces grip to improve handling response, and vice versa, a softer suspension leads to more grip at the cost of more sluggish response. Which is opposite to what most people believe.

I've always wondered how much E&D and actual testing goes into the development of aftermarket springs: are front and rear ride heights and spring rates truly optimized for performance? For sure, most aftermarket shops do not have the resources, data nor testing capability that BMW has. This is why I have good faith in the MP-HAS since it was developed and tested by BMW themselves. Further, it provides adjustability that allows it to be fine tuned through corner balancing and rake setting (front-to-rear height ratio). I don't see the latter as a "concern", but much rather as an advantage because it allows to adjust for chassis production variances and fine tuning for driving style and track setup. Just start with the BMW recommended setting and then fine tune from there.

[JustAnothaM4]

I'm currently running swift springs on my CS and it "looks" great but, it doesn't "feel" good on bumps during transitions. Some people may not have an issue with this and to each his own if they just want the lowered look to remove the huge gap. I don't think the oem shocks are capable of handling any other lowering springs.

I now have a set of proper JRZ RS dampers, linear springs, GC camber plates, etc waiting to be installed. Also a nice set of 19" BBS FI-Rs w/ MPSC2s to make complete the process. Next up are Dinan sways and SPL links.

In short, do it right and do it once! Spend the cash and go high end dampers. I've used Moton, JRZ, MCS, KW Clubsport, TCK DA on previous M3s and this stuff is the best of the best. They feel way more complaint if dialed in properly compared to OEM as you can tune it for street vs track settings.