Your experiences of aftermarket suspension on the Z4 MC

[exdos]

I USE MINE AS A DD AND WITH THE BAD ROADS WE HAVE IN MALTA FIND THAT THE RIDE IS TOO BOUNCY AND STIFF. AT HIGH SPEEDS THE CAR IS RATHER OUT OF CONTROL WITH ALL TEH BOUNCING AND CHANGING DIRECTION FAST IS SCARY.

Kerstien,

Your comments about how you find OEM suspension answers the question. Why did you specifically want the Clubsports? Surely you want the suspension that will satisfies your needs. As Byron says, the KW Clubsports are a track focussed suspension kit and are geared for driving at high speeds on smooth tracks. What you NEED is a better balanced suspension system than the OEM and you should opt for KWV3 or the ACS Racing suspension and adjust the damping to suit your driving conditions. You can adjust the KWV3 and ACS Racing suspensions to very firm for track use, but I can tell you from firsthand experience that such settings are completely unsuited for a DD on most public roads. I have KWV3 coilovers with linear springs on my Z3MC and the ACS Racing suspension on my Z4MC, and I can assure you that when these suspensions are properly set up they will improve the handling of your Z4MC to cope with your roads in Malta.

 

[Beedub]

HI BYRON,

WELL DONE ON A VERY DETAILED REVIEW. I HAVE BEEN FOLLOWING THIS POST AND WAS HOPING THAT YOUR VERDICT WOULD BE THAT THE CLUBSPORTS ARE USABLE RO EVERYDAY DRIVING. I USE MINE AS A DD AND WITH THE BAD ROADS WE HAVE IN MALTA FIND THAT THE RIDE IS TOO BOUNCY AND STIFF. AT HIGH SPEEDS THE CAR IS RATHER OUT OF CONTROL WITH ALL TEH BOUNCING AND CHANGING DIRECTION FAST IS SCARY. AFTER READING THE REVIEW BY EXDOS ABOUT THE AC SCHNITZER I WAS HOPING AFTERMARKET COILOVERS WOULD SOLVE THE PROBLEM. LIKE YOURSELF I WOULD RATHER KEEP RIDE HEIGHT AS CLOSE TO STOCK AS POSSIBLE. WOULD THE KW V3'S BE MORE USABLE IN MY SITUATION? WOULD THE AC SCHNITZER SETUP BE MORE APPROPRIATE. I DON'T HAVE ANY EXPERIENCE WITH COIOVERS SO ANY ADVISE WOULD HELP.

GRETA WORK ONCE AGAIN AND GREAT CAR

THANKS

KERSTIEN

glad you liked the detailed review, i would have to recommend the the v3... ive ridden in a car with the v3 set to soft and it was 100% softer than stock with better control...... the Clubsport 3 way is just ALITTLE extreme.... they can be dialed back but only so much due to those linear race springs, the dampers are basically race dampers with specific valving, the car feels like a giant go-kart, but this is a feel im USED to and like, like i said i feel hardwired into the car, keyed into the road.... i can feel the ruts, the cambers, the steering wheel gently tugging at the wheels run bumps, to me thats exactly what i wanted..... would i want this setup everyday??? f**k no!! i find myself looking well ahead for iron covers and ruts and wholes in the floor..... if you get stand the step back in comfort you going to gain a very serious handling car, it feels wonderful and i havent had my corner balance and tweak up yet.....

Again they are completely silent in their operation.... but i must stress they are a large step back in ride comfort.... the bits i cant transpire into words is how the suspension deals with the bumps, you dont get the huge smash you'd expect in the road settings and im definitely covering ground quicker, on the smoother roads that im confident on.... the car is feeling very special.... id love to be following something serious like a GT3 to see how it fairs... straight line ill eat a gt3 like its a nova... cornering??? well thats a very different story so now its all come together i'd love to test that theory and see how we go..... For sheer cornering, handling and just awesome drive i rate the gt3s/gt3rs the TOP of the tree.

in answer to your question..... it simply boils down to how extreme you want to go....... reading your concerns id run the v3 set to hard, the use the stock rubber topmounts, you'll get a setup thats much better than stock but not pushing things too far..... also the v3 can be run at stock ride height, which was a feature i wanted..... i DO NOT want a car smacking the floor every deep compression....

hope this helps....

Thanks Byron. So are the 3way stiffer than the 2way clubsports?
So if I understood you correctly the v3's will be more comfortable than stock and still Handle better better right? If I decide to do track days I imagine the car will also handle better than stock right?

Exdos from your review your set up is a huge imp over stock. Is it bearable as a dd and where would you place it compared to the v3 and clubsports?

Thanks once again

Kerstien

the clubsport comes in 2 way and 3 way, the cost difference is small.... both use the same race damper and spring.......
the v3 will offer you a firmer setup if and WHEN you want it, and ultimately a much better suspension setup, But you dont need to spend a fortune, how about looking towards the H and R setup, a proper road coilover, height adjustable and very popular in the usa.... After seeing and feeling the quality of the kw... and just googling them as a company.... reading peoples views on them and experiences... im glad i went that way....

the v3 is 100% a road shock, you will be very happy with them with your broken roads.... im guessing the v3 and ACS setup will feel pretty similar both are great items and both offer a real nice Day to day Drive....

 

[Beedub]

I USE MINE AS A DD AND WITH THE BAD ROADS WE HAVE IN MALTA FIND THAT THE RIDE IS TOO BOUNCY AND STIFF. AT HIGH SPEEDS THE CAR IS RATHER OUT OF CONTROL WITH ALL TEH BOUNCING AND CHANGING DIRECTION FAST IS SCARY.

Kerstien,

Your comments about how you find OEM suspension answers the question. Why did you specifically want the Clubsports? Surely you want the suspension that will satisfies your needs. As Byron says, the KW Clubsports are a track focussed suspension kit and are geared for driving at high speeds on smooth tracks. What you NEED is a better balanced suspension system than the OEM and you should opt for KWV3 or the ACS Racing suspension and adjust the damping to suit your driving conditions. You can adjust the KWV3 and ACS Racing suspensions to very firm for track use, but I can tell you from firsthand experience that such settings are completely unsuited for a DD on most public roads. I have KWV3 coilovers with linear springs on my Z3MC and the ACS Racing suspension on my Z4MC, and I can assure you that when these suspensions are properly set up they will improve the handling of your Z4MC to cope with your roads in Malta.

this says it all..... i your raods are really bad where you live, you want to DD the car, id always steer clear of the track kits...
do a search on zpost for v3 , clubsport ect ect and you'll see loads of threads including my own asking the same questions... the answer i got were the same... the clubsport is know to be one of the stiffest available for the z4m.

 

[exdos]

Exdos from your review your set up is a huge imp over stock. Is it bearable as a dd and where would you place it compared to the v3 and clubsports?

Kerstein, I wouldn't be able to live with a Z4MC with OEM suspension: the ride is truly awful, uncomfortable and unpleasant and I don't know how most owners can tolerate it. Likewise, the handling is compromised because of the imbalance in front/rear springs/dampers. Before I bought the Z4MC, I'd already done a lot of mods to my Z3MC, including suspension, so I knew that this problem could be rectified. The ACS Racing suspension has absolutely transformed both the ride and the handling and my car is now a pleasure to drive and I'd enjoy driving it all day on relatively poor A & B roads. Also, with 4 turns on the dampers to stiffen the set-up, the car would handle a trackday extremely well.

I've not driven a Z4MC with KW V3 or Clubsports but I've got KWV3 on my Z3MC, which for that car is a coilover system with linear springs at the front, and I would say there's not too much difference between the ACS Racing and the KWV3. I have driven a few race-prepped cars and been a passenger in a GT3 RS around the Nordschleife, and although track-focussed suspension is awesome on tracks, I certainly wouldn't want track-focussed suspension on a car which is mainly a road car.

 

[kerstien]

I USE MINE AS A DD AND WITH THE BAD ROADS WE HAVE IN MALTA FIND THAT THE RIDE IS TOO BOUNCY AND STIFF. AT HIGH SPEEDS THE CAR IS RATHER OUT OF CONTROL WITH ALL TEH BOUNCING AND CHANGING DIRECTION FAST IS SCARY.

Kerstien,

Your comments about how you find OEM suspension answers the question. Why did you specifically want the Clubsports? Surely you want the suspension that will satisfies your needs. As Byron says, the KW Clubsports are a track focussed suspension kit and are geared for driving at high speeds on smooth tracks. What you NEED is a better balanced suspension system than the OEM and you should opt for KWV3 or the ACS Racing suspension and adjust the damping to suit your driving conditions. You can adjust the KWV3 and ACS Racing suspensions to very firm for track use, but I can tell you from firsthand experience that such settings are completely unsuited for a DD on most public roads. I have KWV3 coilovers with linear springs on my Z3MC and the ACS Racing suspension on my Z4MC, and I can assure you that when these suspensions are properly set up they will improve the handling of your Z4MC to cope with your roads in Malta.

Hi Exdos

I thought clubsports would be better because they have linear springs. Are these only necessary for track days? I was also worried that the v3's maybe too soft and worse than stock. Does the Ac schnitzer have linear or progressive springs? I know you got the schnitzer because you found them at a good price but given the choice which setup would you buy? Would I need camber plates? My mechanic told me not to have camber since I drive her daily.

Thanks Exdos

Byron your 3ways look like some serious kit....def a pity that they are covered up

Can you guys suggest of shops that can give me a good deal on either setup?

Thanks

Kerstien

 

[Beedub]

check out this thread

http://www.zpost.com/forums/showthread.php?t=566902

i think this will answer your questions

linea springs are a race thing, lighter and stiffer

progessive offer ride comfort but dont play to much into that, damping is important to....

listening to what youve wrote about you roads/usage id be steering away from a track kit.

 

[exdos]

Byron,

What are the spring rates of the Clubsports? Did you measure the diameter of the wire of the Clubsport springs?

 

[exdos]

Hi Exdos

I thought clubsports would be better because they have linear springs. Are these only necessary for track days? I was also worried that the v3's maybe too soft and worse than stock. Does the Ac schnitzer have linear or progressive springs? I know you got the schnitzer because you found them at a good price but given the choice which setup would you buy? Would I need camber plates? My mechanic told me not to have camber since I drive her daily.

Kirstien,

IMO, it would be hard for any suspension to be worse than stock! The OEM front/rear spring rates/dampers are totally wrong.

As I've said, I have linear springs (400 lbs/inch) on front coilovers on my Z3MC and when I've got it set up for road driving (softer damper settings) I wouldn't know whether I've got linear or progressive springs, because the car just handles superbly in those conditions. Likewise, when it's on track and set up for that (stiff damper settings) it just handles superbly. That's the beauty of adjustable suspension.

The ACS Racing has progressive springs, although from looking at them, I'd say that they have a tendency to linear rate once the weight of the car is settled on the springs. In comparison, linear springs on coilover dampers require helper/tender springs to take up the slack when the springs are unloaded. I've not yet had the Z4MC on track but I'm very happy with the ACS Racing suspension for fast road use.

Yes, I did opt to buy the ACS Racing suspension primarily because I got them for an absolute bargain price, but I'd also done my research before buying and they were certainly on my list of possibles but new they are at the upper end of the price range. KWV3 are great but the adjustment is awkward on the rear dampers whereas it's much easier on the ACS. The other dampers I was considering were Nitron: I was intending to visit the manufacturer to view the product, but bought the ACS kit before my visit to Nitron. ACS Racing suspension is actually Bilstein PSS9 manufactured to ACS's specification, so how much difference there is between them and a Bilstein PSS9 kit I don't know. If I had to buy again, I'd try to drive the hardest bargain I could for any of the suspensions I've just mentioned and I think you'll be happy with any of them.

I have caster/camber plates on my Z3MC but they have some compliance in them, whereas I've been unable to find any other than solid for the Z4MC, so I've retained the OEM top mounts. I'd want camber/caster plates for the Z4MC to slightly increase caster rather than to increase camber.

 

[bertman]

I'm glad you guys are doing this thread on the Z4M suspension because IMO it's a pretty sketchy setup and I'm a bit worried about fiddling with it.

I've found my car is prone to mild understeer and then snap oversteer. As has been mentioned earlier in the thread the car also dips and lifts / heavily heavily on braking / acceleration which no doubt contributes to the snap oversteer and the kangarooing a lot of guys complain about and dangerously unbalances the car when driven hard.

I'm your average Joe who might run the occasional trackday so I'm not looking to set the car up for competition level performance. What suspension component do you recommend upgrading that will give the greatest bang for buck improvement?

 

[exdos]

I'm glad you guys are doing this thread on the Z4M suspension because IMO it's a pretty sketchy setup and I'm a bit worried about fiddling with it.

I've found my car is prone to mild understeer and then snap oversteer. As has been mentioned earlier in the thread the car also dips and lifts / heavily heavily on braking / acceleration which no doubt contributes to the snap oversteer and the kangarooing a lot of guys complain about and dangerously unbalances the car when driven hard.

I'm your average Joe who might run the occasional trackday so I'm not looking to set the car up for competition level performance. What suspension component do you recommend upgrading that will give the greatest bang for buck improvement?

Bertman,

I think most owners are terrified of tweaking anything on their cars, but once you've got past that stage, you can really improve your car if you do the right things.

You've correctly described what's wrong with the Z4MC and want to know what's the greatest bang for buck. For me, the only thing that will overcome the problems you've identified is the fitting of an appropriate after-market adjustable suspension set up, such as ACS Racing, KWV3, Bilstein PSS9/10, Nitron etc. Nothing else will overcome the unbalanced OEM suspension and unfortunately, it'll cost you in the region of £1.5k to £2k for these suspensions. If there was a cheaper and/or simpler way of improving the ride/handling of my Z4MC, then I would've done it. However, once you've fitted an adjustable suspension you can transform the car to handle like nothing else you've driven before! 8)

Setting up adjustable suspension is NOT a "black art", known only to suspension gurus: anyone can do it provided that you follow a logical and methodical approach. I know some people are very secretive about their set-ups and I've even come across a member on a forum trying to sell the details of his set-up for KWV3! :roll: I make no secret of the settings that I use and happy to tell anyone who might ask. I don't claim any expertise on any of this only experience. All you need to set-up adjustable suspension is patience and a willingness to try different settings and test-drive your car with them, so that you can fine-tune the suspension to make the car ride and handle exactly as you like it. Once you've got the adjustable suspension sorted, you can then go to town on the geometry, then you'll want, spacers, uprated ARBs and RTAB limiters ... Be warned, it's addictive.

 

[daz05]

I'm glad you guys are doing this thread on the Z4M suspension because IMO it's a pretty sketchy setup and I'm a bit worried about fiddling with it.

I've found my car is prone to mild understeer and then snap oversteer. As has been mentioned earlier in the thread the car also dips and lifts / heavily heavily on braking / acceleration which no doubt contributes to the snap oversteer and the kangarooing a lot of guys complain about and dangerously unbalances the car when driven hard.

I'm your average Joe who might run the occasional trackday so I'm not looking to set the car up for competition level performance. What suspension component do you recommend upgrading that will give the greatest bang for buck improvement?

Cheapest option is to look at your alignment first. If you read the thread I posted regarding alignment, I can vouch for those settings in there. If that doesn't work for you take it to the next level.

The standard toe settings seem to be at odds with one another and give the car a disjointed feeling.

The dipping under braking is horrible it makes me feel ill sometimes after a good drive.

 

[kerstien]

Thanks for the great insight Exdos & Byron. Do you know of reputable shops that sell the brands mentioned above? Where did you get your clubsports Byron if you don't mind me asking? I imagine a can get them cheaper than advertised prices on the net?
My first option would be to try find a used set first but not had any luck so far.

Thanks

Kerstien

 

[Beedub]

kerstien i ordered my clubsports from k300 performance, ask for vicki and tell her byron sent you..... ;-) they were simply awesome and even do free shipping for you. The v3 is ready to ship from kw you'll get these within 3 days, the clubsports were a 6 week lead time and are made to order only. i had already purchased the re-inforcement parts last year in prep for doing this mod...

she will supply you the v3 or clubsports....


to all in this thread, i do agree with daz actually, i couldnt not believe the difference in the stock stuff with a proper alignment and setup, it was night and day, i found the stock setup just insanely soft which is the opposite to what alot think on here....

once id added some serious power and braking for me, it fell apart, but stock, imo.... i loved it with stickier tyres and wider rims/offsets. how about bilstein b6 combined with the eibach sport kit?? bet that would be a really nice road combo.

 

[exdos]

i found the stock setup just insanely soft

Insanely soft? The OEM rear springs are from 19mm wire in the middle sections with an effective spring rate in the order of around 800lbs/inch. I bet your KW Clubsports have softer rear springs than those. What are the spring rates and diameter of the wire of the KW Clubsports?

 

[exdos]

Thanks for the great insight Exdos & Byron. Do you know of reputable shops that sell the brands mentioned above? Where did you get your clubsports Byron if you don't mind me asking? I imagine a can get them cheaper than advertised prices on the net?
My first option would be to try find a used set first but not had any luck so far.

Thanks

Kerstien

For suppliers, try these for KW and Bilstein: http://www.evolveautomotive.com/ ask for Imran and tell him Exdos has suggested he might be able to help you.
Alternatively to play off one against another try: http://www.motorsportworld.co.uk/ or http://www.europerformance.co.uk or http://www.larkspeed.com
For ACS: http://rossiters.co.uk/
For Nitron: http://www.nitron.co.uk/

 

[exdos]

Cheapest option is to look at your alignment first. If you read the thread I posted regarding alignment, I can vouch for those settings in there. If that doesn't work for you take it to the next level.

The standard toe settings seem to be at odds with one another and give the car a disjointed feeling.

The dipping under braking is horrible it makes me feel ill sometimes after a good drive.

Changing the geometry is obviously considerably cheaper than installing adjustable suspension and will reduce the tendency to understeer. BUT, it will do absolutely nothing to stop the ride being too firm and crashy, nor the front lifting on acceleration and the steering being floaty, and pitching on braking, which IMO, are the failings of the OEM suspension.

 

[Beedub]

i found the stock setup just insanely soft

Insanely soft? The OEM rear springs are from 19mm wire in the middle sections with an effective spring rate in the order of around 800lbs/inch. I bet your KW Clubsports have softer rear springs than those. What are the spring rates and diameter of the wire of the KW Clubsports?

yep i wrote that correctly... i found the stock setup way to soft for my needs but only after the car had a huge injection of power, better braking, effective springs rates on progressive spring mean nothing, they allow a different type of feel and thats why they are used..... way to much focus is played into progressive, linear, valving is just as important. i have no idea what the diameter of the wire is on the clubsports, drop kw an email and im sure they'll answer that for you some of your calculaions seem very off, like the effective spring rate of the stock rear spring of 800lbs????? sorry john but thats just completely wrong., lets leave the word EFFECTIVE spring rate and talk about ACTUAL spring rate.

whether the spring is softer or harder the FEEL for me on the stock setup was way to soft, it isnt with the clubsport. job done!! i spoke to the owner who was selling the ACS setup on your car and i REALLY wanted to buy it, but his description of them put me off, after a phone call to simpson, who setup the car for the guy you brought that setup from further steered me away, for my aims, it wasnt what wanted. i was pretty disappointed as they were a bargain. i wanted a track focused setup and thats exactly what the clubsport offers me.

 

[Beedub]

stock spring rates taken directly from bmw data

Stock Front progressive spring (1-4 inches of travel after preload)
160-220lb

Stock rear progressive spring (1-4 inches of travel)
240-420lb

 

[Beedub]

unfortunately nitron no longer offer a rear barrel spring, they only offer the conversion to a coilover in the rear.

 

[Beedub]

Cheapest option is to look at your alignment first. If you read the thread I posted regarding alignment, I can vouch for those settings in there. If that doesn't work for you take it to the next level.

The standard toe settings seem to be at odds with one another and give the car a disjointed feeling.

The dipping under braking is horrible it makes me feel ill sometimes after a good drive.

Changing the geometry is obviously considerably cheaper than installing adjustable suspension and will reduce the tendency to understeer. BUT, it will do absolutely nothing to stop the ride being too firm and crashy, nor the front lifting on acceleration and the steering being floaty, and pitching on braking, which IMO, are the failings of the OEM suspension.

maybe it was me, maybe it was the car i own/owned in the past but it never felt overly firm to me??? ever... but then again most of my HARD use was a curborough sprint course with cup tyres on...... maybe this skewed my view....

its feels firm now tho!!! the feel change is night and day....