Shocks upgrade...

My 4S has done 115k, as far as I know on original shocks. The ride seems somewhat harsh and 'crashy', so wondering if replacing the shock absorbers will restore some suppleness. According to the Design911 site, Bilstein B4s are a direct 'OE' replacement, but are there any others in a similar price range I should consider? Only for (generally rubbish) road use, so no need for track firmness or adjustability.

Bilstein B6s are a slight upgrade over the B4s (monotube design, very slightly firmer damping, more consistent performance - apparently) and not a lot more expensive. I bought a set of B6s for my Turbo S from Gert at Carnewal for less than I would have paid for B4s in the UK, and they've been perfect so far. Comfier than the 70k mile-old originals, yet more controlled feeling, with standard springs and ride height. If you want to go lower, the B8 is basically a B6 with a shorter stroke to suit shorter springs.

The harshness and crashyness will be deteriorated bushes in the suspension links. worn dampers are unlikely make the car crashy. Having just replaced all suspension links subsequent to having replaced dampers, I would suggest you won't achieve a nice controlled ride without doing both. If cost don't permit to do that on the whole car - do half of the car I.e. front dampers and coffin arms and leave the rear until funds recover. Or vice versa. Having also just replaced engine mounts- I also highly recommend.

I completely agree with the point about bushings. I had my coffin arms and top mounts replaced at the same time as the dampers. The "tuning fork" arms were fine but the others were shot. The parts are relatively cheap, and although the labour mounts up, you will feel a dramatic transformation in ride and handling in return for the hefty bill!

In the same thought process with my 88k mile 986, work has been done over past year (front coffin arms, geo, rear springs) but it does feel a little wooden and vague when pushed, so further refresh is on my mind, probably as advised via a trip to centre gravity. On the dampers, Im not looking for a sportier set up, I just want it to drive more like it did when it was new, so the OE spec B4s are on my radar, but so are the successors to the well regarded Koni FSD, the Koni Special Active. They are similarly priced to the B4 but the claimed benefit is they react to the forces the car is under as if there were "active" in the way that the system PASM does.

I've had most of the key bits done, coffin arms, top mounts... it actually drives absolutely fine, but feels harsh, particularly at the back end. Having read up on this a bit more, is it fair to say that poor dampers would manifest more in a bouncy, uncontrolled ride rather than harder ride quality? Those Konis look interesting... price-wise between B4 and B6. Its not obvious whether they fit the 4S though... Design911 list them, but Carnewal says no...

I had a 'crashy' suspension problem a couple of years ago. Particularly noticeable at the rear. Took it to the Indy and even though the shocks still did the job and would have passed an MOT, I had them replaced with standard shock replacements. It transformed the ride quality of the car and made the suspension much quieter even on today's roads. It felt much more compliant and smoothed out the harshness. My shocks had done almost 90K and as I found out, well past their best. I would suggest that that at 115k miles, yours will probably be the same.

Keep a lookout for the clinics that centre gravity usually offer in the new year. They will go over all the suspension and advise what needs changing. They can also test your current dampers via a machine in their floor that simulates driving conditions and plots the condition of the dampers.