kW v3 coilovers

[pHilli0]

My KW V3s are now fitted, and are set to as follows
Front rebound: 12 (out of 16 clicks open)
Front bump: 10 (out of 12 clicks open)
Rear rebound: 10 (out of 16 clicks open)
Rear bump: 8 (out of 12 clicks open)

I am yet to get to a track, but on the road I can notice the difference, feels a lot better. One thing, the car feels a bit bouncy over uneven surfaces, reading up it looks like I need to reduce the rebound slightly. Should I do both front and back at once or individually?

 

[monaco_blue]

As they're so easy to change try running on the road with the compression set at 3 from full soft and the rebound 1 or 2 from full soft. The car will be transformed. The settings you're using means on a bumpy corner you'll be all but skipping from bump top to bump top.

 

[BMWZ4MC]

What Monaco-blue suggests is good advice for rubbish road surfaces in the UK. However, with soft settings, beware of high speed compressions such as the bottom of a high speed dip on an undulating country road. My bumper fangs can hit Tarmac under such loads with the suspension set to fairly soft.

 

[pHilli0]

As they're so easy to change try running on the road with the compression set at 3 from full soft and the rebound 1 or 2 from full soft. The car will be transformed. The settings you're using means on a bumpy corner you'll be all but skipping from bump top to bump top.

Ok can i confirm the spec I need to try?
Front rebound: 12 (out of 16 clicks open)
Front bump: 10 (out of 12 clicks open)
Rear rebound: 12 (out of 16 clicks open)
Rear bump: 10 (out of 12 clicks open)

BMWZ4MC do you have any recommendations, I live in the country and I want the best for uneven fast country roads.

 

[exdos]

do you have any recommendations, I live in the country and I want the best for uneven fast country roads.

I also live in the country and do most of my driving on the twisties. I have KWV3 on my Z3MC and AC Schnitzer Racing suspension on my Z4MC so here's my findings.

For fast road set up you want the suspension to be able to cope with the worst surfaces you'll come across. I've found that on the roads, softer is better than firmer and when you get your set up correct your car will be awesome and give you loads of confidence. And, the ride will also be comfortable. As your starting point, set the front for both bump and rebound to half way from full soft. At the rear, set the bump to 5 from full soft and rebound to 4 from full soft. Give that a try and get used to the way the car feels, then progressively try increasing both the bump and rebound settings at the front, by one click at a time. If you do this, you'll find that you've suddenly gone too firm by one click, which you'll feel through your hands when you go over a noticeable bump in the road. When this happens, back off the bump setting by one click and see how that feels, if it now feels better, try backing off the rebound by one click also, and gauge this. You now know your front settings are somewhere near correct. Then just adjust the front settings to what you like best.

Once you've sorted the front settings, you do the same thing at the rear, by increasing bump and rebound by one click at a time, and keep testing the changes. When you feel that the ride is too firm, soften the rebound setting by one click first and see if that improves things, then try softening the bump by one click. If you go about setting up the suspension by making small changes at one end of the car only, you'll soon hone into the correct set up.

With regard to track set up, you'll find that your fast road settings will work well in the wet, but for the dry settings, because tracks are generally pretty smooth, you can go much nearer to full stiff on both bump and compression all round.

Hope this helps.

 

[pHilli0]

do you have any recommendations, I live in the country and I want the best for uneven fast country roads.

I also live in the country and do most of my driving on the twisties. I have KWV3 on my Z3MC and AC Schnitzer Racing suspension on my Z4MC so here's my findings.

For fast road set up you want the suspension to be able to cope with the worst surfaces you'll come across. I've found that on the roads, softer is better than firmer and when you get your set up correct your car will be awesome and give you loads of confidence. And, the ride will also be comfortable. As your starting point, set the front for both bump and rebound to half way from full soft. At the rear, set the bump to 5 from full soft and rebound to 4 from full soft. Give that a try and get used to the way the car feels, then progressively try increasing both the bump and rebound settings at the front, by one click at a time. If you do this, you'll find that you've suddenly gone too firm by one click, which you'll feel through your hands when you go over a noticeable bump in the road. When this happens, back off the bump setting by one click and see how that feels, if it now feels better, try backing off the rebound by one click also, and gauge this. You now know your front settings are somewhere near correct. Then just adjust the front settings to what you like best.

Once you've sorted the front settings, you do the same thing at the rear, by increasing bump and rebound by one click at a time, and keep testing the changes. When you feel that the ride is too firm, soften the rebound setting by one click first and see if that improves things, then try softening the bump by one click. If you go about setting up the suspension by making small changes at one end of the car only, you'll soon hone into the correct set up.

With regard to track set up, you'll find that your fast road settings will work well in the wet, but for the dry settings, because tracks are generally pretty smooth, you can go much nearer to full stiff on both bump and compression all round.

Hope this helps.

Exdos, thanks great advice from the suspension guru! I know I can adjust the rears without taking the wheels off, not sure about the fronts, ive not yet tried

 

[tertius]

Just one comment - its generally recommended to always work from Full Hard (as this is a known fixed point, whereas Full Soft is not necessarily) - i.e. always wind them up to full hard and then count the clicks back.

Also whenever I change settings I always do this - wind them right up and then count back - I never assume that its where I left it! That way you always have consistency.

I had a long conversation with Guy at Nitron about this and this was his recommendation.

 

[exdos]

Good point. I've found though that if you turn the adjusters through the full range to both extremes you need to identify the first click when you turn in the opposite direction and then count the total number of clicks in the range, and this is the same whether you adjust from full hard or full soft.

I also keep a written record in the car of the adjustments and the dates on which I've made them so I don't get "lost" when I'm setting up.

 

[pHilli0]

Right the rears are adjusted and feel a LOT better. The fronts have been set to half way on the rebound (the bottom adjustment). I couldn't see any way to adjust the top bump rate? Where is the adjustment point on the front?

 

[pHilli0]

Current setup is rears 5 bump and 4 rebound. Fronts are 6 rebound, not sure on the bump setting.

 

[pHilli0]

Any one any ideas?

 

[monaco_blue]

Right the rears are adjusted and feel a LOT better. The fronts have been set to half way on the rebound (the bottom adjustment). I couldn't see any way to adjust the top bump rate? Where is the adjustment point on the front?

It's done with the tiny hex wrench/key on the knurled purple knob/wheel supplied in the tool kit. The adjustment point is at the top of the strut piston accessed from under the bonnet; remove the dust cap from the top mount.

 

[pHilli0]

Ah thanks Moncao, much appreciated.

 

[pHilli0]

I am finding the rear shocks are occasionally bottoming out and thumping on fast bumpy roads. They are set at 8 rebound and 8 bump. What do I need to tweak to prevent this?

 

[exdos]

I am finding the rear shocks are occasionally bottoming out and thumping on fast bumpy roads. They are set at 8 rebound and 8 bump. What do I need to tweak to prevent this?

Have you lowered the car too much, which would shorten the travel of the dampers?

If you know the locations on various roads where the bottoming out occurs, then the occurrence should be repeatable, so try stiffening the bump setting and test drive on the roads that cause the problem, and that should solve the issue. Leave the rebound alone, too stiff on rebound on bad public roads will jar your neck on a good journey.

 

[pHilli0]

I am finding the rear shocks are occasionally bottoming out and thumping on fast bumpy roads. They are set at 8 rebound and 8 bump. What do I need to tweak to prevent this?

Have you lowered the car too much, which would shorten the travel of the dampers?

If you know the locations on various roads where the bottoming out occurs, then the occurrence should be repeatable, so try stiffening the bump setting and test drive on the roads that cause the problem, and that should solve the issue. Leave the rebound alone, too stiff on rebound on bad public roads will jar your neck on a good journey.

The ride height is 355mm hub to arch all round. Its not super low I can get over speed bumps without too much drama. I will try stiffening the bump by 2 and reduce the rebound by 1. Test that and repeat adjustments. Do yours bottom out at any time on country roads?

 

[exdos]

The ride height is 355mm hub to arch all round. Its not super low I can get over speed bumps without too much drama. I will try stiffening the bump by 2 and reduce the rebound by 1. Test that and repeat adjustments. Do yours bottom out at any time on country roads?

The rear springs on the KWV3 on my Z3MC look almost coil bound, but it never seems to bottom out, even at The Ring where there is one part of the track where it creates maximum loading (as told to me by Dirk Hacker, vice president for engineering in the M Division). Likewise, for the AC Schnitzer Sports suspension on my Z4MC.

 

[pHilli0]

The ride height is 355mm hub to arch all round. Its not super low I can get over speed bumps without too much drama. I will try stiffening the bump by 2 and reduce the rebound by 1. Test that and repeat adjustments. Do yours bottom out at any time on country roads?

The rear springs on the KWV3 on my Z3MC look almost coil bound, but it never seems to bottom out, even at The Ring where there is one part of the track where it creates maximum loading (as told to me by Dirk Hacker, vice president for engineering in the M Division). Likewise, for the AC Schnitzer Sports suspension on my Z4MC.

Ok good to know. Ill keep tweaking until its stops. If it doesnt there may be an issue.

 

[exdos]

There is the possibility that you might be thinking that you've hit the bump stops when your suspension is actually too stiff. So if going stiffer doesn't work, then go softer. Make sure you keep a written record of what you're doing, so you don't get lost with the changes.

At the end of the day, adjusting suspension is just methodical "suck it and see".

 

[pHilli0]

There is the possibility that you might be thinking that you've hit the bump stops when your suspension is actually too stiff. So if going stiffer doesn't work, then go softer. Make sure you keep a written record of what you're doing, so you don't get lost with the changes.

At the end of the day, adjusting suspension is just methodical "suck it and see".

Yea good idea. It does seem like a bit of voodoo but I am sure there is complex science happening in the shocks! One thing I found odd is that the number on the rears that is showing is different on both sides even though I have done the same number of clicks on (8 clicks). The number displayed on the dial is lets say 3 on the right and 2 on the left. Not sure if that is indicative of a problem, or the expectation is they should read the same number on the dial on both sides, in which case I would have potentially different "clicks" ? Not sure if the numbers should match or I failed at counting clicks.