My 997.1 Carrera S needs a bunch of things (new rear tires, an alignment, new bump stops up front) and at 15 years/nearly 75,000 miles, I'm thinking I might just bite the bullet and do a significant suspension refresh. In doing so, I'd be looking to maximize ride quality while maintaining or improving "feel" from a performance perspective (as opposed to outright performance, which isn't that important to me). Current setup is stock shocks, H&R Sport springs, stock roll bars and original bushings. It is a PASM car and I'd like to maintain that going forward.

Currently, the ride quality is basically fine in terms of impact harshness but it does feel a little oversprung, as it gets a bit bouncy and nervous when hustled. I also suspect that some of the bushings could use a refresh since they look a tad crusty and I do have some of that occasional front suspension rattle people mention occasionally (intermittently, weirdly, and only over low speed small bumps).

I've searched the archives here but wasn't really able to find the guidance that I needed since most people seem to maximize for performance in a way that's not that important to me. I do want to improve driving feel, but I don't care about outright performance that much since I'll likely never track it. It is a daily driver for me in a bumpy city commute, so it's more important to me to maintain good ride quality. For some benchmarking, my previous daily drivers were a 2017 Mercedes C63S and a 2003 BMW M3, so all in that range of "comfortable enough for a daily driver but too harsh for your grandma to enjoy riding in."

I had thought about Ohlins R&T as an option, but don't love that it would disable PASM. Also thought about Bilstein PSS.

So, two questions. First, any recommendations on coilover kits that would fit the bill? And second, what components would folks recommend replacing in the vein of "if you're in there, might as well..."?

 

Have you considered a DSC Sport Controller as part of that proverbial bullet? I don’t have one but have never heard anything bad about them. It’s on my to do list.

 

Start with a DSC and you might need to do nothing more than that. Other than the aforementioned bushing refresh, and maybe a strut mounts to address the clunking. The DSC controller is that good.

 

I converted to the Ohlins R&Ts. I think they will be too harsh for you.
Plan to replace anything that is or has "rubber" bushings in the suspension attachments. Inspect struts carefully for signs of fluid leaking - replace (in axle pairs) as necessary. You may want to go back to stock springs but consult with DSC guys if you go that route.
I don't think you could go wrong with the DSC system.

 

Interesting to hear you say that. I hadn't considered a DSC, primarily because I thought of it as more of a performance mod and also for cost reasons. Between coilovers, a DSC, some new suspension components (e.g. drop links), bushings, new tires, an alignment, and labor, it wouldn't be too difficult to turn this into an $8,000 job or something which seems like overkill.

I'd considered going back to stock springs anyway. I like the ride height drop, but I think the car is oversprung with the shorter springs. Makes sport mode with PASM basically useless on anything other than glass smooth roads. This is part of why I was thinking of going whole hog and doing coilovers, because a system that's better matched in terms of shock valving and spring rates should theoretically be superior to lowering springs on stock shocks.

 

I recently went through a similar exercise. I wanted to improve ride quality and performance a little but without degrading ride, while also keeping cost in mind. Also, there are speed bumps in our neighborhood so I didn't want to go too low. I looked at Elephant Racing's suspension builder because they score different packages for both ride comfort and performance. I decided to look at upgrades in a "staged" way, figuring I could upgrade incrementally along the way:

Stage 1: Lowering Springs with rubber/soft parts refresh and DSC - TechArt or Eibach springs / new bumpstops, upper mounts, rubber bits / DSC controller
Stage 2: Stage 1 plus Bilstein B6 strut/shocks
Stage 3: Stage 2 plus GT3 or TPC Racing adjustable anti-roll bars and Elephant Racing drop links
Stage 4: Stage 3 plus GT3 front and rear lower control arms and Elephant Racing rear toe control arm

Also, I considered substituting Bilstein ($) or Tractive ($$$) coil overs for stages 2, 3, or 4. Note none of these have spherical bearing arms. The ride harshness and additional maintenance isn't worth the trade-off to me.

You may also want to consider tire choice, some tires ride harsher than others. In their comparison tests, Tire Rack notes ride quality as one of their evaluation factors. I installed Michelin PilotSport 4Ss as part of this upgrade.

So far, I've only installed Stage 1 and am completely happy with the results. The car rides so much better but the suspension is well controlled. The DSC controller is a game changer for sure. I installed one on my 2012 Carrera GTS and my wife, who drives a 2009 Carrera S, noticed the better ride. I'm installing one in her car too. I've done an autocross and am satisfied with the car's performance. I hope this helps.

 

Amazing answer, thanks. Hadn't seen the ER suspension builder until now but will spend some time checking it out. Looks like I may wander myself into an $8,000 job after all lol.

Re: tire choice, current tires are Michelin PS4S and will be replaced with same. I've never skimped on rubber and don't plan to start with this car.

 

Unless you're shooting for a specific ride height/rake or want to play with compression/rebound settings, coil overs are redundant.

 

I wouldn't say I want a highly specific ride height and I'm not likely to fuss with settings a lot, but I do like the lowered stance and would prefer not to return to stock ride height.

 

Not sure if this helps at all but I have an 05 C2S with PASM. I am not lowered and wanted a stock ride. Ended up with Bilstein B4 Damptronics. Ordered those from amazon and all the other necessary bits from FCP Euro - whatever they recommended, which was quite a bit. Turns out my mounts were bent on one side and one of the shocks was bent. Car rides perfectly now and isn't floaty, as it was before, at over 80mph.

 

I will add to the DSC controller list. It is a performance mod, but in the sense that performance of these cars should be defined by the ability to take it to the track and then drive your wife to dinner afterwards. The DSC does that perfectly, it makes the suspension more responsive and more reactive to pavement conditions. The result is a smooth yet responsive ride.

 

this is copied over from a response I did on another thread here:
https://rennlist.com/forums/997-foru...l#post15034196

I would HIGHLY.... I mean... HIGHLY recommend you replace the Top Strut Mounts which have rubber bushings in there that gets old, cracked, torn, stretched and tired. Especially when lowering the car you may think your strut mount is ok at first, but there will be added stress due to the lower springs and it will crack/tear for sure. Trust me, this is one job you do not want to do again because you start hearing some strange knocking a few months after doing springs. Ask me how I know If the strut mount is worn out and tired you will also see a bit more "sagging" in the front. It may look like the fronts are slammed and the rear is too high. These will definitely lead to knocks and slams when bottoming out . With fresh strut mounts the relationship and weight balance between front drop and the rear drop will look much more even and handling will be much better. Less prone to bottoming out as well.

Also highly recommend replacing the strut bearings which look like a flat donut. These help to keep any twisting motion through the strut turning smoothly.
Bump stops are cheap and should be replaced for added protection and strength since you may be bottoming out a lot sooner with lowered springs.

Recommended, but not necessary, are "while your in there" replacing anything that has tired bushings:
-sway bar bushings (important to order correct size for your model year/make)
-sway bar links
-lower control arms ( Y fork)
-track control arms ( coffin shape)
-inner tie rod to steering
-outer tie rod to hub.
-check all grease boots to the hubs.

this adds up really quick, but if your car has anything near 75k miles or more... then you will be amazed at how well the steering control and feed back feel after replacing those old suspension bushings and parts. Precision and tightness to the steering and handling make a really nice difference.

 

Thanks to everyone for the help so far. I've put together a package that looks like this...

FRONT. Will retain H&R lowering springs and stock swaybar, as well as any component not listed below, and for now I'm leaning toward polyurethane bushings as opposed to stock rubber. I'm more concerned about compliance in terms of damping than I am NVH, but happy to be corrected if folks think stock rubber would be better.

• New B4 PASM struts
• New front lower control arms/wishbones
• New front lower control arm inner and central bushings
• New front outer tie rod and inner tie rod ends
• New front camber plates/rubber bushings
• New front swaybar bushings
• New front drop links (stock)
• QUESTION MARKS: do I need new caster control arms?

REAR (will retain H&R springs, stock swaybar, as well as any component not listed below)

• New B4 PASM struts
• New lower control arm inner and central bushings
• New upper control arm bushings
• New rear toe control arm bushings
• New rear shock upper mounts
• New rear swaybar bushings
• New rear drop links (stock)
• QUESTION MARKS: do I need new rear lower control arms/wishbones? Do I need new rear upper control arms/wishbones? What about caster arms or toe control arms?

I feel like I'm missing stuff here. What am I missing?

That's my current thinking on hardware. Also seriously considering a DSC controller upon advice from many of you, but that can be done later. Don't love the idea that I'd need to solder in a new accelerometer, but such is life.

 

Here is the link from FCP Euro as to what they recommended I buy when I did my B4 Damptronics (got the B4s from Amazon, much better price at the time). https://www.fcpeuro.com/cart?utm_sou...1060847848%232

 

I just read another thread about the DSC, seems like even if you wanted to do it now, you couldn’t. Chip shortage = back orders.