Thanks Guys!
I'm thinking about doing a few part series of posts that might be of interest to some of you. I think it's a great way to also gather feedback and learn from you and vice versa you might find something interesting and useful for yourself. Although I am an engineer (software), I'm just an enthusiast at the end of the day so don't expect anything to technical
PHASE I: Suspension, Handling and Geometry
In this post I will:
Go over suspension upgrade options and try to help anyone deciding between H&R and KW H.A.S. kit
Destroy some myths about "rice" mods
Show and tell how I got my cls63 handling and feeling like a proper sports car with no compromise in comfort, but rather the opposite
Background:
Having done an excellent 3k mile road trip to the south coast of France at the end of summer I've managed to identify some issues and limitations with the car. These issues became evident mostly because of the average speeds which were *allegedly* pretty high and like any car, especially one weighing around 2 tons, started showing it's slushy and boat'y character. I did change the shocks and top-mounts few months prior and had new OEM drop links fitted, but the control arms did have 60k on them so this could mostly be the reason why, you be the judge.
Car had H&R springs and lowering links at the back, I thought that crash'y suspension feeling was just a given with performance car, it still handled pretty great, yes there was quite a lot of body roll in tight corners and "dive" in on the outside wheel so you had to sort of "catch" the car going through them and always predict and think ahead, but it's a pretty heavy car right.
I did experience understeer a few times and a massive lack of camber at the front. I'm not bashing the platform whatsoever, maybe I just expected something unrealistic from such a car, but it has brought me here.
The Solution:
Luckily I had friends who had done many mods on their cars and even as a passenger i could feel a massive difference from those changes. Although those were Porsches and M cars, the type of mods were common so I started carrying out research to see what's available for this platform.
Majority of people just do what I've already had: H&R and links lowering, so I put my googling goggles on and went on the internet scout mission.
In endless scrolling, image searching contacting people from allover the world really I've managed to gather a little guide of possibilities for the platform:
Bushes:
Full Selection of Poly-bushes for front, rear and even subframe :
STRONGFLEX - Polyurethane Components
Adjustable camber arms rear:
Camber/Caster adjustment/ top mounts:
Adjustable rear toe:
Adjustable anti roll bar:
Lowering:
Bracing:
Mono-ball Thrust arms:
Coilovers:
*
they require airmatic and adaptive damping delete so does need coding out, I've found out about these from a friend in Taiwan. He had a few of his clients run it (who are happy with it) and he decided to do it for himself and seems to be happy with it.
Ideally I would love to delete airmatic and retain adaptive dampers, so KW H.A.S. for the rear would be perfect, I even emailed them begging to make it, but due to hassle with TUV they kindly declined a few times. Another option was to just contact BC for rear springs with spring sleeves for the rear, but it felt wrong to me to mix and match the springs as I don't understand the kinematics so much as to do something like that. I think this is a great option for someone who doesn't see much benefit from adaptive damping and airmatic at the rear and wants more reliability from rear. here are some pics he sent me :
Now it doesn't seem like such a "dead" platform, does it?
I couldn't find much feedback on these parts so I decided to "risk" it for selection of mine.
My build:
Conveniently my air compressor for the rear airmatic (which I've grown to hate) has gotten tired, overworked and blew a fuse (the 60amp one if I'm not mistaken) and stopped working a week before long awaited upgrade install so I had to also add new compressor, filter, relay and fuse to the basket.
Here is what I went with:
- New Inner and outer steering/toe arms.
- New lower control arm ball joint.
- Lower control arm pollybush yellow (111996A)
- K-Mac Camber and Caster adjustable top mounts (Full Race Edition)
- Whiteline Adjustable drop links.
- Full Bracing
- Syncrodesign custom made mono-ball thrust arm
- SilverProject adjustable rear arms unfortunately.
- KW H.A.S. kit
The logic behind was to eliminate any play/vagueness/slush/roll. Make struts do the work and unlock adjustability.
How I understood it lots of forces and energy were lost in rubber bushings and body flex before they even got to the strut. Having McPherson strut we don't gain much camber at all and strut tower is under more stress than usual.
Was I worried about NVH? Absolutely.
Did I anxiously though I might've spent all this money and ruined the car? Hell yes
Did I still do it? Someone had to.
Luke has installed it for me, as some of you might know he is the guy to go to for any suspension and especially alignment work, really knows what he is doing, do recommend.
I was really worried about some of the parts, but most of them were really good quality, the top mount although looks weird, is super precise and easy to adjust and install, the full race bearing is so much better than the stock plastic top mounts.
Rear camber arm from silver project: only 1 arm had space and holes for height sensors, arms is too wide and it makes contact with rear anti roll bar, hence the car is higher than I'd like for the time being. I will be changing airmatic bags and go for hardrace next. So I would avoid those.
The Result
KW>H&R
I can confidently say that KW is a better spring, especially for the UK roads, it's much more compliant and less crashy/spongy. It's just superior. I was worried that I'm wasting money but I am super happy. 10/10 improvement.
NVH
None. Zero. Nothing. Car is smoother, quieter, no vibrations or noises, more compliant it glides over British roads whilst having all the grip and control you would want. It really reminds me of my friends e92 m3 on KW v3.
I'm yet to put more miles on it, will take it on the backroads this weekend to do some proper testing. In all honesty I am surprised, a bit proud of myself and very happy with how it turned out.
Hard to describe it, but it feels like you have a full weight of the car in your steering, which doesn't feel sluggish or loose, it's nice and firm, you have all the grip in the world, no surprises. I'm yet to feel the limits. I've taken some corners where it would "fall" and "dip" before and roll way too much, now I'm nowhere near the limit it just breathes through them. any uneven road or bumps are "swallowed" and no grip is lost. Car does really feel like an extension of you, no need to plan and think of road surface ahead, just point and shoot (obviously weight is still there, but so much more manageable, and these mods hide it so well). I think what surprised me the most was high speed stability and braking is phenomenal, it just does what you want, braking feels more precise now, no drama, just nice progressive as much as you give it. Would recommend.
It has to be experienced to understand.
I hope this information somewhat helps anyone who are on their journey to improve the car. Although from first impression it looks like a bunch of "rice" mods that will ruin the car. I can vouch it's way different and complete opposite. More grip, More control, More refinement, no downsides yet.
This is how the car should've been from the factory.
onto the brakes next....
