I recently installed a set of Koni FSD's with the stock springs. Along with that I used Ireland Engineering Fixed Camber Plates and installed Continental ExtremeContact DWS on my 07 R56 S. I've been VERY happy with the ride, but had a few questions.

It seems like the car sits has more body roll than before. Is this something I should experience from these shocks? The ride is certainly better for this daily driver, considering the shocks that were on there were the originals at over 80K miles. I just cant get over how much body roll there is and why I'm just now noticing it. Did I do something wrong with the install or is this common? I do plan on getting a rear sway bar soon if everyone tells me this is par for the course with these FSD's.

The car also feels like it sits just a little taller than before, I recently pulled up an old photo and it looks the same, but just feels so different it's really weird!

Another byproduct of the install is how quick the steering is now, very responsive and maybe a little twitchy!

Suggestions? Am I tripping?

 

It may be the tires. The DWS is famous for soft sidewalls and soft ride. You could see if more air pressure affects it.

 

Just a thought...
Were the OLD struts DEAD when removed?
If they were flat, and you were driving around on the springs, the RIDE WILL BE DIFFERENT...
A firmer ride is not necessarily better....a WAGON rides flat..but handles pretty bad...same for a car with a worn suspension....
one thing to remember..koni FSD's are progressive...meaning their response is not liner to input...many track junkies dislike this cause it is harder to "ride the edge" but for a daily...it is kinda nice IMO.

 

Thanks for the responses! Yes the originals I took off were done for. I could pull and push the old struts with my hands when I took them off.

The ride is certainly improved on the bumps, potholes and many of the other issues we have with our roads in Oklahoma.

I think my next step will be a rear sway! Time to check out the Marketplace!

 

An RSB, a heavy adjustable one set to max will mitigate any roll. Just to satisfy yourself, before you jack it up to install the bar, grab the rear wheel well and lift and see how far it moves then do the same after the install. I'll bet it don't move a MM.

 

After the replacement to the FSD I had the same feel at first but after a few days the FSD settles. Take it around a few twisty in a week and you will love how it handles the corner..

 

One more question about the sway bar... Do I need to get new, beefier end links for the sway bar or just use the originals?

 

I did not upgrade the sway bar but instead I opted for the JCW strut brace and it stabilized the front end rolls.

 

Unfortunately, dampers have nothing to do with body roll.
Springs and sway bars do.

Dampers do what they are supposed to do, dampen spring oscillations.

 

For street use, IMO, the stock end links will likely be fine.....that what most folks do. If the car will be tracked or driven very hard, longer term, the end links may wear....but changing them are trivial...
Changing the rear sway bar is a nice change on a mini...I think you will like the change...my suggestion...run it tight for summer...more mild in the winter till/unless you get some track time and learn how the bigger rear bar changes handling unless you go with a mild increase (snap oversteer on a on ramp if you let off the accelorator is possible if you make the car too neutral)...

 

They will, however, change the dynamics of body roll.
Stiffer dampers will slow down the onset of body roll, but in a medium or long winding
turn you'll still get to the same roll angle, only a little later.
With quick transitions, you will notice less roll.

 

Since you changed several things at once, it is hard to determine if any one change made more of a difference than another.

I would expect the IE plates (adding front camber) would have improved the front turn in and steering response.

One easy thing to try is adjusting the tire pressure. You didn't mention what sized tires you tried. Put the pressure up to 40 psi and see how that affects the body roll and general feel of the car. I run my 16" snows at this pressure and have had no issues.

The rear sway bar will make the car feel more nimble, but not necessarily give you a sensation of less body roll.

Have fun,
Mike

 

There is way too much incorrect information in this thread.

OP, the dampers are tires could both be contributing to the sensation of additional body roll. (yes, shocks DO have a significant effect on affect body roll).

On my 07S, the IE plates were about 3/8" thicker than the stock upper mount, which will increase ride height a bit. Maybe not enough to tell in a photo, but enough to mess with the geometry and roll behavior.

With all those changes, you will need an alignment if you haven't already had one. Correcting your toe may help the twitchy steering.

A super stiff rear bar will help reduce roll, but it probably not a good match to your soft tires and dampers, and it will hurt the ride quality. Also, since you haven't done anything to increase the roll stiffness in front, the roll will be unbalanced. Even with my 19mm H Sport bar set to the softest setting, the front seems to roll quicker than the front, which makes the steering too twitchy. I'm also curious why you put IE plates on the car. Unless you're going to the track, all they are doing is putting more stress on your struts and making the ride worse. And if you ARE going to the track, your shock and tire selection isn't the best for that usage.

Finally, 40psi is way too much tire pressure, and a strut brace will not stabilize the car in roll, so don't bother with that either.

 

I think the FSD is actually a digressive valving. At low shaft speeds there are large rebound forces while at high shaft speeds there are smaller rebound forces.

The IE camber plates would have given the OP more negative camber which would have caused the front wheels to toe in. Time for an alignment. Toe-in doesn't generally cause twitchy steering though.

Since when does a rear swaybar hurt ride quality? When going over bumps in the road the rear swaybar is typically not doing anything unless you're only hitting a bump with one side of the car. The whole point of a larger RSB is to increase the rear roll rate relative to the front.

For aggressive driving 40psi isn't too much tire pressure. For cruising around on the street yeah you wouldn't want to run the tires that high.

 

That's the whole point. FSD stands for Frequency Selective Dampening.

 

Went with a similar setup on my 2011 JCW. Koni FSDs, IE fixed camber plates, HK RSB, NM torque arm insert and 215/45 Michelin Pilot Super Sports. Daily driver and light track work. Couldn't be happier, of course I specced the car with standard suspension when new, not the JCW suspension. Handles completely neutral and oversteer is gone (IMHO).

Dave

 

I think you answered your own question. Anytime road is not even from side to side you will have reduced ride quality in the form of increased body jerk and head toss. On my mini it's quite noticeable even with the bar on its softest setting.

40 psi is too much for any driving. You reduce the contact patch of the tire and lose grip. Modern low profile tires have enough sidewall stiffness that there's not much benefit.

 

"40 psi is too much for any driving."

No it isn't. My 2010 required 49 in the front to stop the Dunlop Star Specs from rolling over onto the sidewalls. How much motorsports experience do you have to be making such ex cathedra statements?

 

Ok, a little review of your former posts discloses your statement about being a chassis and suspension engineer. Maybe you're assuming that anyone interested in the best possible handling is free to install any suspension parts they want including camber plates. In stock category of autocross we can't by rule. So we run higher pressures to keep the tire under the car.

 

I only suggested going up on tire pressure so that the OP could see if that changed anything wrt the body roll. My car came with 17's and is recommended at 38 psi. I understand that this is with runflats, but I have had very even wear at 38 psi.

Everyone has different driving expectations and requirements, that is why this is a good forum to express opinions and experiences.

Have fun,
Mike

 

The car may feel little taller than before, because when you had the old bad struts, the car may have sank down when you sat down

The quicker the steering may be due to the new tires which have different characteristics than the old worn tires.