Your experiences of aftermarket suspension on the Z4 MC
- Thread starter exdos
- Start date
RedUn said:exdos, Are you corner weighting? If your after on road compliance I can't recommend it enough
If it was a race car or a dedicated track car it would be the next thing I'd do and then I'd reset the geometry. But I'm unsure how this is worthwhile at other times when you just chuck stuff into the car, and sometimes carry different passengers of varying weights with differing fuel loads? Can you give me the heights of your car from the ground to the top of the wheel arch at each corner of your car so that I can see how much different corner weighting is to OEM settings?
My Z4 isn't corner weighted but i've done previous cars with good results.
Think about most of the times you go for a blast in the car, normally it's just you driving with nothing in the boot, why wouldn't you want your geo as good as you can get it in this situation?
I noticed an increase in ride quality plus they also take off and land better
You'll be suprised how far out your weight distribution is, as accurate as you have set it. With the amount of money you have spent on the car and suspension is it not worth the extra £250 to finish it off properly?
:wink:
Think about most of the times you go for a blast in the car, normally it's just you driving with nothing in the boot, why wouldn't you want your geo as good as you can get it in this situation?
I noticed an increase in ride quality plus they also take off and land better
You'll be suprised how far out your weight distribution is, as accurate as you have set it. With the amount of money you have spent on the car and suspension is it not worth the extra £250 to finish it off properly?
:wink:RedUn said:You'll be suprised how far out your weight distribution is, as accurate as you have set it. With the amount of money you have spent on the car and suspension is it not worth the extra £250 to finish it off properly?
I take all your points and when I set my ride heights I do account for my weight being in the car. If I paid others to do all the work for me and never laid a spanner on the car myself, then I'd consider that the job is now finished and should be professionally set up and corner-weighted. BUT, I do all the spannerwork myself and enjoy experimenting with different geometry and suspension settings and like exploring the handling characteristics that changes make. Also, the ACS Racing suspension is not height adjustable at the rear, only the fronts; although shims can be used at the rear to affect height changes.
Further, for the sake of aerodynamics, I also prefer a little more rake than there is with the OEM set up, which must be at odds with corner-weighting. At the end of the day, setting up a car is all about compromise and I'd prefer to get what I like empirically and being an inveterate tinkerer, this is a large part of my enjoyment of cars.
exdos, That's fair enough I thought it was worth mentioning that's all. I do all the spanner work myself but I'm also a perfectionist and I don't have 60k to spend on alignment equipment so I begrudgingly pay for that to be done!
As for the nose down I'm sure its good for aero reasons but I'd try and keep the same drop all round compared to what the standard BMW heights are as they will do corner weighting as standard. Maybe you need a massive DTM splitter?
As for the nose down I'm sure its good for aero reasons but I'd try and keep the same drop all round compared to what the standard BMW heights are as they will do corner weighting as standard. Maybe you need a massive DTM splitter?
RedUn I appreciate your input. 
I'd be bankrupt if I paid for every different set up with an alignment that I've tried in the past 10 years! I've devised a very simple DIY method of checking alignments that I do, which gives consistent and repeatable results. It takes me about 10mins at the most to check after I've done the initial alignment check for a car.
I hear what you say about nose down, but it's acknowledged that the car has lift at speed, so if I can counteract some of the lift, then my geometry at higher speeds should remain closer to their static settings making it much more stable than the OEM set-up with OEM suspension in higher gears: I don't want any vagueness around Schwedenkreuz or through Fuchsröhre. I'd love a massive front splitter and huge rear wing, but not really practical for our roads and I couldn't cope with the ridicule I'd get. 8)
I'd be bankrupt if I paid for every different set up with an alignment that I've tried in the past 10 years! I've devised a very simple DIY method of checking alignments that I do, which gives consistent and repeatable results. It takes me about 10mins at the most to check after I've done the initial alignment check for a car.
I hear what you say about nose down, but it's acknowledged that the car has lift at speed, so if I can counteract some of the lift, then my geometry at higher speeds should remain closer to their static settings making it much more stable than the OEM set-up with OEM suspension in higher gears: I don't want any vagueness around Schwedenkreuz or through Fuchsröhre. I'd love a massive front splitter and huge rear wing, but not really practical for our roads and I couldn't cope with the ridicule I'd get. 8)
john heres a few snaps of the kw competition 3 ways....
things i love, the remote canisters, new style adjustment wheels, range of height adjustment, and those awesome awesome camber plates..... car is currently running around -2.6 front camber, ride height is all over the place and needs some tweaking, but very pleased with this so far, its very stiff but on the softest setting feels pretty close to oem, in full track mode.... well..... it feels that stiff it may damage something! lol, i also went with Re reinforced Rear mounts with race bushes, and the fronts due to those solid mount camber plates i went with reinforcment plates but they weight a freakin tonne, you asked for this info so long ago.... really sorry i wasnt able to post pics alot earlier, also BTW the the competition kit comes with this lovely in car tool kit, the innox line stuff is real quality...
overall very very pleased just need to get a proper corner balance done and sort the slightly out ride height ( not the piss easy task i once thought, lots of wheel on, off to get things spot on)
heres a few choice snaps.
black reinforcement plates visible
kw camber top plates with solid uniball mounts ( note special order longer bolts)
top adjusters and further adjustment on remote canisters and bottom of the strut
rears in place , you can just see one of the remote canisters here, note, im a wimp and im running this rather high but im still suprised how low this setting is, as you can see the perch was set high by me.
in car tool kit
rear damper off the car.
things i love, the remote canisters, new style adjustment wheels, range of height adjustment, and those awesome awesome camber plates..... car is currently running around -2.6 front camber, ride height is all over the place and needs some tweaking, but very pleased with this so far, its very stiff but on the softest setting feels pretty close to oem, in full track mode.... well..... it feels that stiff it may damage something! lol, i also went with Re reinforced Rear mounts with race bushes, and the fronts due to those solid mount camber plates i went with reinforcment plates but they weight a freakin tonne, you asked for this info so long ago.... really sorry i wasnt able to post pics alot earlier, also BTW the the competition kit comes with this lovely in car tool kit, the innox line stuff is real quality...
overall very very pleased just need to get a proper corner balance done and sort the slightly out ride height ( not the piss easy task i once thought, lots of wheel on, off to get things spot on)
heres a few choice snaps.
black reinforcement plates visible
kw camber top plates with solid uniball mounts ( note special order longer bolts)
top adjusters and further adjustment on remote canisters and bottom of the strut
rears in place , you can just see one of the remote canisters here, note, im a wimp and im running this rather high but im still suprised how low this setting is, as you can see the perch was set high by me.
in car tool kit
rear damper off the car.
Byron,
Your KW Clubsport kit looks great! 8) The Inox Line dampers are very well made - I've had them on my Z3MC for over 7 years and they still look almost like new. I'm sure for your purposes for a track-focussed car, the kit will be ideal, especially with the uprated front and rear top mounts.
I know what you mean about keep taking the wheels off and on to get your set up right: I think my wheels now think about jumping off the car themselves every time they see me!
Because the height adjusters are on the springs, which are in-board of the wheels, this means that a height difference on the adjusters of, say, 2mm, makes a height difference at the wheel of, say, 6mm, so rather than messing about setting the ride height, at the outset, I take the front and rear wheels off on the same side of the car and measure the difference in ride height at the wheel, with the adjusters set at their lowest setting, then do the same at a much higher setting. If I measure the difference in ride height at the wheels (F & R) and then divide these numbers by the differences on the adjusters (F & R) between the two different settings I can calculate how much I have to turn the adjusters to give me the ride height at the wheels that I want. Once I know this, I find that it's much easier to set up the car with the ride heights that I want with the least number of times that I have to remove the wheels. If you disconnect the front ARB whilst adjusting, you can make adjustments to the ride height much easier.
How are you going to access the rebound adjusters on the rear dampers?
Your KW Clubsport kit looks great! 8) The Inox Line dampers are very well made - I've had them on my Z3MC for over 7 years and they still look almost like new. I'm sure for your purposes for a track-focussed car, the kit will be ideal, especially with the uprated front and rear top mounts.
I know what you mean about keep taking the wheels off and on to get your set up right: I think my wheels now think about jumping off the car themselves every time they see me!
Because the height adjusters are on the springs, which are in-board of the wheels, this means that a height difference on the adjusters of, say, 2mm, makes a height difference at the wheel of, say, 6mm, so rather than messing about setting the ride height, at the outset, I take the front and rear wheels off on the same side of the car and measure the difference in ride height at the wheel, with the adjusters set at their lowest setting, then do the same at a much higher setting. If I measure the difference in ride height at the wheels (F & R) and then divide these numbers by the differences on the adjusters (F & R) between the two different settings I can calculate how much I have to turn the adjusters to give me the ride height at the wheels that I want. Once I know this, I find that it's much easier to set up the car with the ride heights that I want with the least number of times that I have to remove the wheels.
If you disconnect the front ARB whilst adjusting, you can make adjustments to the ride height much easier. How are you going to access the rebound adjusters on the rear dampers?
exdos said:Byron,
Your KW Clubsport kit looks great! 8) The Inox Line dampers are very well made - I've had them on my Z3MC for over 7 years and they still look almost like new. I'm sure for your purposes for a track-focussed car, the kit will be ideal, especially with the uprated front and rear top mounts.
I know what you mean about keep taking the wheels off and on to get your set up right: I think my wheels now think about jumping off the car themselves every time they see me!
Because the height adjusters are on the springs, which are in-board of the wheels, this means that a height difference on the adjusters of, say, 2mm, makes a height difference at the wheel of, say, 6mm, so rather than messing about setting the ride height, at the outset, I take the front and rear wheels off on the same side of the car and measure the difference in ride height at the wheel, with the adjusters set at their lowest setting, then do the same at a much higher setting. If I measure the difference in ride height at the wheels (F & R) and then divide these numbers by the differences on the adjusters (F & R) between the two different settings I can calculate how much I have to turn the adjusters to give me the ride height at the wheels that I want. Once I know this, I find that it's much easier to set up the car with the ride heights that I want with the least number of times that I have to remove the wheels.
How are you going to access the rebound adjusters on the rear dampers?
thanks john luckily im nearly their with the rear ride height, drivers side rear is slightly lower so need to raise this a touch, and the front looks like a 4x4, lol as i set it pretty high, i will bring this down the next dry day when i can get the car out and tweak things, as for the font and rear rebound, im pretty happy with the kw recommended settings, once i dial in the ride height and get to the track i will further tweak but the rear takes some minor trim removal, a complete nightmare first time round but know i know the score a 15 min job now
but im all honesty i wont be messing this those settings to much, once i get the car aligned i may consider removing the rear trim and place it in storage, leaving the strut tops exposed, but this seems a shame imo....the car makes no rattles, creak bangs or knocks from the new setup..... really looking foward to tracking it and seeing what this setup can do.....
very very pleased with it all..... fitting took me 3 days however with looking after my son ect ect, sadly with the weather and home commitments i really havent been able to test/enjoy the car...... so hoping to do some final tweaking, then get a proper setup done....
pleased to report the kw race range fits like oem components, i was REALLY impressed with the fit, finish and quality of the kit.... very very nice.. im sure those rogue rear mounts make things harsher however.... with the rubber out the front tops its really added some nice feel into the mix!!
Beedub said:[i will further tweak but the rear takes some minor trim removal, a complete nightmare first time round but know i know the score a 15 min job now
You can drill a 1" hole through the interior carpet trim directly above the adjuster on the rear damper and then fit a rubber grommet which looks very tidy and OEM. Personally, I like the rebound at the rear to be very soft on the roads, for both comfort and grip, but on track I like it as stiff as the front so I always want access to the rear rebound adjuster.
exdos said:Beedub said:[i will further tweak but the rear takes some minor trim removal, a complete nightmare first time round but know i know the score a 15 min job now
You can drill a 1" hole through the interior carpet trim directly above the adjuster on the rear damper and then fit a rubber grommet which looks very tidy and OEM. Personally, I like the rebound at the rear to be very soft on the roads, for both comfort and grip, but on track I like it as stiff as the front so I always want access to the rear rebound adjuster.
its covered but the roof box mech, not something i want to keep doing to be honest, unfortunately i cant drill this piece!!! i went with kw's Recommended settings and im pretty pleased with it so far, if i need to adjust it i wont hesitate to pull this out... (their settings are tested on the ring which is far from smooth tarmac)
i was half tempted to remove the roof box mechanism and trick the micro switch into thinkings its still present but, thats way to ghetto for me, every single clip/screw is in place on this car and id like to keep it that way!! this Saturday i have a trackday so need to be up early to get the ride height dialled in.
pretty excited as its my first outing on the track this year due to family commitments as you know, normally by this point ive done 4-5 days..... so pretty excited to see what she can do.....
Beedub said:
I find KW's recommended settings for KWV3 on my Z3MC, on our "wonderful" A & B roads, far too stiff, particularly at the rear. In comparison to our public "patchwork quilt" roads, the tarmac at the Nordschleife is as smooth as silk and you can get away with KW's recommendations there. James May does have a very fair point about many modern cars having bad rides because of manufacturers using the Nordschleife in development. I could recommend a number of our roads that manufacturers should use in preference to develop suspension systems which would test their cars far better than the Nordschleife.
Have a great time on your trackday at the weekend
exdos said:Beedub said:
I find KW's recommended settings for KWV3 on my Z3MC, on our "wonderful" A & B roads, far too stiff, particularly at the rear. In comparison to our public "patchwork quilt" roads, the tarmac at the Nordschleife is as smooth as silk and you can get away with KW's recommendations there. James May does have a very fair point about many modern cars having bad rides because of manufacturers using the Nordschleife in development. I could recommend a number of our roads that manufacturers should use in preference to develop suspension systems which would test their cars far better than the Nordschleife.
Have a great time on your trackday at the weekend
so far im very happy at the kw settings, i love that Feel!! ive just realised however that ive adjusted the rear a few clicks to much so i need to reset and re dial those in!, its all great fun, really enjoying playing round with it..... infact, f**k it.... im off for another garage session
RedUn said:I can vouch for KW's quality also i've been ran them on previous cars for getting on for 10 years in total with not one problem!
Yeah very pleased with them , this is the first time I've owned a proper race damper with linear competition spring sets... So far I'm very impressed, very firm ride however, the street based v3 setup is probably the best compromise and runs the progressive springs like the majority.
Quality of the hardware is perfection. Can't wait to see what I can do with cup tyres.
daz05 said:
+1 on the hardtop. Not sure if it's a) the shape of them or b) the colour. Just doesn't look right to me.
Love the rest of the car and mod's though Beedub