Hey Guys; I’ve been thinking of upgrading suspension and am thinking H&R’s. Roads are terrible, but upsizing my tires to 40 series 19’s helped a lot and I’m pleased with the Falkon 453’s.
I’ve had kw v3’s in the past on an old r32, but it’s been years since riding in a stg2 c5 s4 avant with H&R’s I believe.
Any thoughts/experiences would be appreciated.
John
What’s your definition of an “upgrade”? You mentioned terrible roads, so you want what, softer suspension?
I hear h&r are pleasant I had kW v3 in my past. I hear the h&r are a touch softer? Might depend on the application. I actually think the stock setup is decent tho. Might be minority tho
By “upgrade” I’m thinking improved performance and handling; decreased body roll and better overall balance - cornering. I’d rather run 18’s and sport suspension than have sloppy suspension. RSB might also be of help.
Ok yes, what you described but make sure all your control arms and bushings are in good condition. If it were me I would make sure all stock components are in good form before we dive into possible suspension tweaks. If you have checked and all looks good then yes to what you said above plus great alignment.
Might want to consider upgrading bushings as well. The 18s will help the ride, but once you dial in with coil overs, harden some bushings (if u upgrade), and even add a sway you might increase nvh and decrease ride quality a bit, might end up somewhere in the middle and you might be happy?
Remember the car weighs over 4000 lbs so stripping weight where you can helps a lot. For instance Light weight rotors wheels and tires. Coils likely weigh less as well so it helps in more than one way. V8a6 seems to be happy with his h&r coils and he seemed to think ride improved!
Not sure on rear sway from experience, but you might be able to get the h&r coils and rear sway that work nicely together? Remember that once you start going down this path it gets slippery, but hopefully you strike a nice balance with slightly increased comfort and cornering, they do not always go hand and hand, but 18s will help, assuming you do not get rock hard tires. You cannot have your cake and eat it too, at least at this point in time.
Is there any way to LIFT the suspension in these cars? Would coilovers accomplish that?
I took my car on a fire road in the mountains this weekend, and ended up high-centered on a pile of snow in the road. Another inch of ground clearance and I would’ve been fine. Luckily, a nice dude with a truck winch was able to pull me out using my front bumper tow hook. Pretty sure I broke a coolant line somewhere in the process - this would be the third time I’ve had coolant line issues in my car >:( Anyways, increasing my ride height by an inch (or more?) temporarily would be awesome, since I drive dirt roads probably more than I ought to.
Lightweight rotors, wheels, and tires will help overall car performance, but it won’t reduce the suspension load, will it? Since the weight of the rest of the car that’s “being suspended” wouldn’t change - those items are “under” the suspension, not “over” it.
Not sure what kW or H&r offers on this car, but my kW v3 on my Subaru you could lift it I believe .5-1 above stock.
If I were to really do it, I would explore air struts or at least electronic dampening control within the car. Gives you much more versatility.
Google a few coil overs and see what the ride heigh adjustability is.
Agreed, but adding that would make the car more alive, agile, and more tossable if that’s even possible for a car of this weight and size 
I think the OP would be happy with the results based on what he is looking for, thought your are right t wouldn’t necessarily really reduce overall load.
Why I said it becomes a slippery slope when you start talking suspension, so much to tinker with and it is easy to make it handle worse than stock ;).
I found the stock s6 setup to be pretty good overall, hence why I didn’t mess with it. Cannot underestimate that you need to get the stock setup in good working condition before you start tinkering.
If after that, you still desire more than consider coils with mild spring rates. If I were doing it again, I’d do the above and develop or procure an electronic dampening, and possibly ride height adjustability system from inside the car, well if I could do it for less than a small fortune ;-p
Thx for the input guys - didn’t mean to open a can of worms as I do understand the slippy slope of downgrading your “experience” when trying to do the opposite to some degree :D.
I had thought some guys were running H&R’s and was fishing for their thoughts. Personally I can say that the stock suspension with the 35 series 19’s was harsh for stock - meaning potholes, road imperfections, etc made you think “ouch!” - road are bad here. I can report that new 255 40’s fixed that. Now however it could stand to a bit more grounded (on rails) and the body roll is noticeable. From my experience once you have enough rubber on the ground; stiffening the suspension is warmly welcomed. Adding a RSB might be all the difference I need – man, with the spare out the understeer is nuts - feels like dukes of hazard!
Mounts and bushings would be a good thing to look at replacing as well. I still have under 100k, but I’m sure I’d notice a difference with replacing these - maybe not upgrading.
Coil overs will adjust the total body ride hight and that would have probably been all you needed to not get snow stuck.
Sucks about the coolant tine Im trying to figure out what line would be that far down
The body roll starts but can be stoped with a good rear sway bar. I noticed a big difference when added. The springs are the second line of defence. H and Rs are good entry level parts. The big body S6 will deffinitly need a bigger sway bar but I dont know too much of whats offered for the car.
Coil overs are nice due to there ability to adjust the ride hight and stance but for me fixed springs and shocks with the right weight rating are the best way to go. I cant stand adjusting the coil overs even if you can raise and lower the car.
If found that lightweight rotors and rims helps the cars harshness and to add what VTGT said it plays a secondary roll in the cars nimble reaction to dips drops and pot holes. The lower weight helps the suspension react quicker and with less mass. its the same principle with off road cars. They give bigger travel to help but they also concentrate on lighter components to help with the impact and response.