Suspension plan: M4 ZCP LCI2 MT

[MPoweRo]

Feedback from the brain's trust please with regards to the following plan for suspension. The car (in SOII) is coming in January (thanks Mo @ Southbank BMW).

So you can assess for 'fit for purpose' my intention is to take the car to club-sprints 3-5 times per year and to drive it to work twice a week, then sometimes to a nice restaurant gallery or what have you. I'm even planning on a few short road trips which will be a change from the 1M as the ride and road noise are too unpleasant with the wife and kids (8 and 4). This is part of the reason for going for an M4 rather than the M2 - the ability to switch between cruising quietly and (relatively speaking- I'm used to the clubsport coilovers in the 1M) dialling up max-attack and smashing out a good track session. The EDC adjustable suspension, therefore, is critical to keep. I also want to drop the car a bit and push the wheels out with spacers - all so long as it doesn't affect the car's track ability and safety.

With respect to suspension settings I think I'd like to lower the car by 1.5cm at the front and 1cm at the rear, and set the front negative camber to -2.5, probably 0 toe and the rear with -1 camber and either 0 toe or slight toe in.

What I propose is this:

1) KW HAS kit
2) TC Kline strut tops
3) 10mm spacers F+R (need recommendation on the best quality here, and preferably in black as I'll have the black 666 wheels)
4) Second set of 19inch wheels with PSC2s

And I'm not sure if I should be considering:
5) Adjustable sway bar end links to correct for the drop in ride height;
6) Heavier sway bars; and
7) Any bushes

The choice of the strut tops is largely about NVH as the TC Kline ones apparently use the stock mount. I've looked at sourcing the M performance HAS kit but it's more like $3k rather than $1250. I don't want to go too wide with the spacers and throw the geometry out for the sake of looks (on my previous car they had the positive side effect of seemingly softening the spring rate which makes sense as they would lengthen the lever arm).

Anyhoo, any advice welcome. Cheers, Rohan.

[MPoweRo]

Uh oh. 5th post down now and no replies!

[drgmt]

Mate presumably you are getting an M4 competition?

My feeling would be give it a good go stock with the GTS DCT software update. Honestly it seems very well sorted to me as is.

I did put spacers on more for looks as I think the handling benefits are borderline. I went with eibach 12mm all round.

[MPoweRo]

Cheers (fellow Dr I think),

Yes M4 comp as in the title. Manual though.

You're right I should keep it stock for a bit but don't know how long I'll last!

[mynameisplayer]

Are there track days with like-minded M3/4 enthusiasts? Tag along and pick some brains. Otherwise ask SouthernBM or Evolve Technik if any customers are track oriented.

[drgmt]

It would be great if 10 or 15 guys could get together and hire Wakefield racetrack for the day. They would be awesome.

[MPoweRo]

Originally Posted by mynameisplayer

Are there track days with like-minded M3/4 enthusiasts? Tag along and pick some brains. Otherwise ask SouthernBM or Evolve Technik if any customers are track oriented.

Yes good point they would be good resources.

[MPoweRo]

Originally Posted by drgmt

It would be great if 10 or 15 guys could get together and hire Wakefield racetrack for the day. They would be awesome.

Sure would. We did something similar with a whole bunch of us from the hospital at Sandown a while back. I've never had so much track time on one day.

[mynameisplayer]

Righto, start a thread! One suggestion, not school holidays.

[M4 CSL]

1) KW HAS kit (Great Way to ruin Comp pack ride, don't waste money here.)
2) TC Kline strut tops (Spend more item one, and will come with Camber plates)
3) 10mm spacers F+R (need recommendation on the best quality here, and preferably in black as I'll have the black 666 wheels)
4) Second set of 19inch wheels with PSC2s (Good choice)

And I'm not sure if I should be considering:
5) Adjustable sway bar end links to correct for the drop in ride height;
6) Heavier sway bars; and
7) Any bushes

If you go Dinan anti Sway bars, they come with front adjustable end links.

aFe do a nice Sway bar, but no end link adjust, can buy either SPL or Fall Line.


There is no Toe adjustment on stock cars. What you really want is quality Adjustable toe links. You can go cheap, but cheap will be noises, and most likely require regular maintenance. You only get what you pay for.
Dinan will set you back $2K AUD. But won't bind, and have covers so won't need regular maintenance.

The Comp pack has an upgraded rear sway bar, already. Its about equal to the Dinan kit. But Dinan frnt is 32 mm, same as aFe. Dinan is adjustable bar settings as well as end links.

But what you really need to decide, is how much of a difference you want to make. HAS just ruin the ride. Its for GAYlords (Stancelords) That want to pose and don't care about handling.

If you want to track, best save more money and go straight to KW CS. They come with camber top hats. Otherwise, you will mess around with the lesser ones, they won't give enough of improvement, and you will be left wanting.

The Comp pack is very comfy for the street, : )

[elisiX]

Are you serious? KW HAS is one of the best ways to retain stock ride and get height adjustment.

I’m running H&R springs which have the perfect drop, for looks, but only increased ride firmness by 10-15%.

However programming US Comfort spec suspension made it more comfortable than stock.

[M4 CSL]

Originally Posted by elisiX

Are you serious? KW HAS is one of the best ways to retain stock ride and get height adjustment.

I’m running H&R springs which have the perfect drop, for looks, but only increased ride firmness by 10-15%.

However programming US Comfort spec suspension made it more comfortable than stock.

I am very serious. I have read 50 threads, where people loved them for 3 weeks, then hate them. Including H & R springs. Then see them for sale in the classifieds. They are a cheap way to ruin the ride of your car. Says at least 50 people that have had them. Mind you, people generally lower there car to much for LOOKS, to the point f the suspension, not being able to work correctly. Could have a lot to do with it.

There are no Free lunches.

Some people can learn from others mistakes, some people insist on making them, themselves.

It starts out, Oh wow they are great. It transforms the LOOK of the car. Then it either goes quiet. Then in other threads, I hear this noise all the time. Then, I can't wait to go back to stock. I have ruined the ride. Even with the V1 and V2's. First its love, then its I don't know. Then its for sale. Its surprising how fast you will adjust to a firm ride, if the car gives you superior handling.

I understand not everyone is about performance. If your not, you really should leave it stock. But the young don't like the wheel gap. They are about looks over function. So they drop it on the ground, it looks fast, but it is not. They will get owned on the track.

If you are serious about making a real performance difference, you will steer clear of any HAS. If you just want a cheap improvement on looks, and don't drive fast, then HAS my appeal to you.

[MPoweRo]

Thanks all.

I certainly don't want to go backwards in performance for the sake of appearance.

The other option, having looked at coilovers but wanting the ability to switch ride settings from the cabin, is the KW DDC kit. Not sure where I can get this and I can't see much in the way of feedback on this forum.

Based on the current feedback, I won't order anything until I get the car (apart from some CF cosmetic stuff) and try it on track with some PSC2s and upgraded brake pads/fluid and see how it feels. By then, hopefully there will be more feedback on the KW DDC and I can make an informed choice.

M4 CSL, you seem to have track experience. What pads are you using and which braided lines have you gone with?

Re the track day - next year I will enquire with Sandown and start an EOI thread.

[bloke79]

Hi Ro1M,

Going through a very similar process for my own '17 M4 Competition (getting ready for more club-day track work).

I'm going a slightly different route.

I'm going to get the latest software, and load the M4 CS EDM, MDM, Diff and DCT settings. I've also brought a set of 18" rims (Volk ZE40's) and some 255/40/18 and 295/35/18 rear A050's. Apparently there's a fair bit of a performance improvement in doing that which doesn't require changing out springs/shocks/swaybars, because the hardware is the same between the two cars outside of the rims.

I've also ordered a set of the Revozport brake cooling ducts, Ferrodo DS.Uno's to help with braking as well as some Castrol SRF brake fluid.

Have taken the M4 to Sandown stock and ran a 1.27 - coming from a little Lotus Exige S it certainly takes a while to get used to the extra 'heft', although the car is very stable under speed.

[bloke79]

Oh - you might also want to reach out to these guys: http://www.dscsport.com/

They provide a controller for active management of suspension for a number of models. Specifically, they install a yaw controller and adjust the damper control dynamically depending on the lateral load on the car - such as stiffening the front dampers under braking and loosening the rears so to increase stability... Same deal under acceleration, etc etc.

I asked them and they had planned on having a product in market early next year for our cars - if there's enough demand, they'll probably bring it forward.

It's worth a second or two a lap (around a low 1 min track) so definitely a worthwhile mod with no impact to NVH under usual use.

[M4 CSL]

Originally Posted by elisiX

Are you serious? KW HAS is one of the best ways to retain stock ride and get height adjustment.

I’m running H&R springs which have the perfect drop, for looks, but only increased ride firmness by 10-15%.

However programming US Comfort spec suspension made it more comfortable than stock.

http://f80.bimmerpost.com/forums/sho....php?t=1414375

Just one of many, showing how bad HAS are.

[fredo3]

I think you'll be surprised how well sorted the M4 is on track (I'm assuming it's the same as the M3). Tyres are a great idea, but unless you are chasing serious lap times and you are doing a lot of laps I wouldn't bother with suspension mods. Good luck either way.

[MPoweRo]

Originally Posted by bloke79

Hi Ro1M,

Going through a very similar process for my own '17 M4 Competition (getting ready for more club-day track work).

I'm going a slightly different route.

I'm going to get the latest software, and load the M4 CS EDM, MDM, Diff and DCT settings. I've also brought a set of 18" rims (Volk ZE40's) and some 255/40/18 and 295/35/18 rear A050's. Apparently there's a fair bit of a performance improvement in doing that which doesn't require changing out springs/shocks/swaybars, because the hardware is the same between the two cars outside of the rims.

I've also ordered a set of the Revozport brake cooling ducts, Ferrodo DS.Uno's to help with braking as well as some Castrol SRF brake fluid.

Have taken the M4 to Sandown stock and ran a 1.27 - coming from a little Lotus Exige S it certainly takes a while to get used to the extra 'heft', although the car is very stable under speed.

Thanks for that Bloke79.

Yes, I'm thinking just starting with the tyres and brakes first and see where that takes me. The 1M had Endless ME20 pads and PSC2s as well as Bilstein Clubsport coilovers - I'll try and source the ME20s for the F82 and will have to get a set of 19s for the PSC2s.

I like the idea of the brake cooling ducts. I must say though, the tyres degrade before the brakes on the 1M (and I'm not hanging about) so they might not be necessary for me.

A stock M4 has a 1.24 at Sandown in it I reckon - much longer legs than the N54. You can probably make up most of that time at the high speed left hander on the back straight.

Cheers.

[MPoweRo]

Originally Posted by fredo3

I think you'll be surprised how well sorted the M4 is on track (I'm assuming it's the same as the M3). Tyres are a great idea, but unless you are chasing serious lap times and you are doing a lot of laps I wouldn't bother with suspension mods. Good luck either way.

I'm sure looking forward to letting it of the leash.

[KiwiInOZ]

Hi Op,

I've put the mPerformance HAS Kit in and like it. I got it for corner balancing first and looks second.

BMW recoded the dampers to suit and it handles much better. The car still needed corner balancing though, as the BMW install manual works off ride height, not weight balance which defeats the purpose.

Had Swift spring but they were too violent.

Don't forget ya brakes. I have Endless MX72 pads, fine around town with no noise, Motul RBF 660. Tires are MPSC2s.

If nothing else, do the brakes. The factory has to make compromises for driveability in this area over performance.

If you've got a second set of wheels I would go with Hankook 221s on those. The soft are fast but only last 6 laps so would recommend mediums for longevity.

[MPoweRo]

Originally Posted by KiwiInOZ

Hi Op,

I've put the mPerformance HAS Kit in and like it. I got it for corner balancing first and looks second.

BMW recoded the dampers to suit and it handles much better. The car still needed corner balancing though, as the BMW install manual works off ride height, not weight balance which defeats the purpose.

Had Swift spring but they were too violent.

Don't forget ya brakes. I have Endless MX72 pads, fine around town with no noise, Motul RBF 660. Tires are MPSC2s.

If nothing else, do the brakes. The factory has to make compromises for driveability in this area over performance.

If you've got a second set of wheels I would go with Hankook 221s on those. The soft are fast but only last 6 laps so would recommend mediums for longevity.

Thanks Kiwi.

I've looked at the m performance kit but was quoted $4k including install which is very close to kw club sport price. Where did you source yours? (And how much, pm if you prefer?) Have you tracked with them too? Interesting to hear BMW were able to update the EDC software for the kit as it isn't freely available in Aus. Can you elaborate on that? I've never had a car corner balanced but hear it really makes a difference.

Re brakes - absolutely yes. I love the Endless ME20s but they are noisy on the street. Did the MX 72 hold up at the track? My brake guy (Howard of Race Brakes in Yarraville) tells me I hammer brakes. I too use RBF660.

I will check those tyres out.

Thanks again.

Ps I love kiwis, my wife is one!

[KiwiInOZ]

I got the kit for 1195 USD from getbmwparts in the US. They can't ship internationally but will let you arrange a courier to collect and ship here. Install was around $900 at North Shore BMW IIRC. They had the coding.

There's still a lot of body roll compared to dedicated race coilovers, but pretty good. Sway bars would help.

MX72s are ok for me, but depends how long you sit on the brakes. In my other cars I always ran ME20s, but they were dedicated race cars. Need the driver aids off too, they cook brakes, but you probably know that.

221s are the best bang for buck out there, otherwise the Yoko A050 if you can't find the sizes.