As there's always plenty of questions about this subject on AO, I thought I'd put my experiences and thoughts on here so it may be of help to fellow owners.
Car is is a 2001 156 sportwagon 1.8 twin spark.
So about 4 weeks ago I had a partial suspension rebuild, including upper and lower wishbones, GTA anti roll bars - powerflexed, rear hub bushes and some other stuff i can't remember. Obviously the car was much better, but I couldn't help thinking how much better it would be with new springs and dampers.
I intend on running the car for about 18 months to 2 years, so against the advice of the sane proprietor , I decided to spend more than the car is worth on dampers and springs
So after Lord knows how much research and speaking to Guys who have this kit, I decided on the Bilstein B12 kit. Bear in mind everyone I'd asked about the B12 kit were GT 3.2 or GTA owners NOT twinspark owners. They were very complimentary about the B12 kit, but there were also other Guys who really rated the Koni sports kit, including my brother who said it transformed his 3.0 GTV , but I thought I'd try the B12 kit
Anyway, it didn't really work out, it would've been excellent on a track but was hard and crashy on normal roads, it felt a bit like the car was going to fall apart within days if not hours. We reckoned it could be something to do with the twinspark not being as heavy as the 3.2's ( yes we had the correct springs on the front). I did go around a long sweeping bend though and it gave me enough confidence to keep accelerating, in the old guise, it would be panic stations at 40mph. The dampers in this kit were B8, the shortened ones as oppose to B6, the standard ones. We had a chat about the car and after a test drive it was agreed it wasn't working how Bilstein tell you it does in their media, I think they need to test it a little more on a Twinspark. A few more tweeks/alignments were made, but without me testing it anymore I was told it wasn't getting any better, that it ought to be swapped and at no cost to me. Fair play
What did I want to swap for? Well I wanted to keep the car as low as it's original SW veloce spec on Nivomats, but when I checked with EB spares about the availability of saloon sportpack springs, I was told they were special order from Alfa and IIRC £400. Not paying that for springs, so decided to stick with Eibach pro kit springs with saloon suspension mounts, not the Nivomat ones which can raise up rear end.
So that was the springs decided on. Shocks/struts/dampers?? well over a week I changed my mind every hour or so between Koni Sport and KYB Excel G and sometimes in between wondered whether to be a complete idiot, go the whole hog and get some KW V2's. I read a few horror stories about KYB's failing in a short time, but I read as many horror stories about Konis, Bilsteins and KWs, the internet is full of them! I toyed with the idea of taking the FSD's off the GT, putting some KW's or Koni sports on that, but the GT is excellent so didn't dare mess with it. I had to get real on price and was a little worried after the harshness of the B8 dampers that Koni might not be different enough. So after confirmation from KYB that I could use the Excel G's up to 30mm lowering, we decided to give them a go, maybe I would be happier with a slightly better than OEM ride rather than only being able to tank it down a freshly laid dual carriageway.
So the outcome is that without anyone in the car it sits level, I can slip 2 fingers between the tyres and the arches. It's a pretty good ride actually, I'm certainly no where near blown away by it, but it takes the knocks of our normal roads pretty well and it goes around roundabouts extremely flatly with little body roll which was 50% of what was bugging me about how it used to be (scary). I think I was expecting to drive out of the garage in a Bentley diguised as a 156 sportwagon, that's probably pretty unrealistic although the GT aint far off! (i get to go in lots of Bentleys/Rolls/Merc 5/600's so I know).
The only realistic downside is that with me, a passenger and about 35 stone/220kg of adults and about a 100 records in the back, the tyre rubbed on the rear arch for a couple of seconds in pulling out of junctions whilst turning. So maybe Alfa weren't so daft when they put Nivomat self levelling on originally cos I used to put some right weight in the boot and never got any rubbing.
You may be wondering why I didn't put FSD's on the sportwagon if they're so good on the GT. Well when i first had the GT the ride was poor to the point I wanted either rid of the shocks or the car. New Michellin tyres and an alignment completely changed the ride, I can't comprehend why it had such a staggering effect, but it did. So there was too much chance I'd spend a lot on FSD's and they'd be cack like they originally were on the GT.
If I had my 3 of my 156, one as it was pre works, one with the wishbones etc and GTA arbs done and one with wisbones etc, GTA arbs and the new dampers and springs, what would I spend my cash on considering I'm running it 2 years max? - the middle option.
I was advised against doing the shocks and springs and I should've really taken that advice, but I'm happy enough and it's kind of been a good experiment in view of future cars.
I should reiterate that I don't know anyone who has tried the B12 kit on a twinspark, plenty of people rate it on a V6 and unless they've only ever ridden a horse and cart, i"m sure it's very good.
Thanks go out to Ned at Autolusso for his no quibbles service and for answering a barrage of emails in a response time that puts the emergency services to shame. Thanks also to the mechanics that never get enough repect.