Suspension Setup Qs

[ScoobySteve]

I recently got a bunch of engine items sorted on my car so I spent this past Saturday out driving. While I had the car on the lift for the engine stuff I replaced my swaybars with an 26.8mm up front and an 18mm outback. I've also got new tires (Dunlop Direzza Z1 Sport Star Spec).

Since the engine is well-sorted...now's the time to focus on the handling. I'm pretty sure my rear shocks are finished. My front strut inserts were replaced (with stock Boge / Sachs replacements) about 15,000mi ago. I've never done the rears so I can only assume they have 132,000mi on them. They feel woefully underdamped.

I was thinking of doing Koni all the way around as I really like the adjustability factor. I'm thinking of also getting a set of the 200lb front springs while I'm in there. I notice they come in lowering and non-lowering varieties. Personally, I don't think my 944 needs to be lowered at all. I'm not planning on changing out the torsion bars -- at this time.

Lastly, I'm trying to figure out what to do with the front strut mounts. I have an '86 so they are not too expensive to replace. I haven't noticed anything obviously wrong with them, but my mechanic friend noticed they deflect a lot when raising and lowering the car on the lift. Are they cooked? And if so, should I spring for the spherical bearing replacements?

I live in CA and do almost exclusively street driving. But I like my cars on the taut side. I could just replace the struts and stock with original, but I have a feeling I'd end up being dissatisfied -- especially with the sticky rubber and bigger bars.

I was hoping some of the more experienced guys could chime in before I start writing checks.

[flash968]

i will be interested to find out if you think those tires are as noisy as they are on a car i just drove

200lbs is a touch stiff for the stock torsions on that year, but not too bad - should work ok - if you are going to do konis, i would go ahead and do the adjustable height conversion - that way you can decide where you want the ride height, and corner balance the car - however, the boge struts can handle a stiffer spring - you could install 160 without issue at all, and i'm pretty sure the valving on yours is the same as on the 968 - depending on which springs are in your car, you could probably stick in 968 springs and call it a day - or you could go stiffer, but again the torsions will be the limiting factor - i had the uber rare porsche eibach tech/art 150/230 progressives on them for a while and they were great

[ScoobySteve]

Originally Posted by flash968

i will be interested to find out if you think those tires are as noisy as they are on a car i just drove

200lbs is a touch stiff for the stock torsions on that year, but not too bad - should work ok - if you are going to do konis, i would go ahead and do the adjustable height conversion - that way you can decide where you want the ride height, and corner balance the car - however, the boge struts can handle a stiffer spring - you could install 160 without issue at all, and i'm pretty sure the valving on yours is the same as on the 968 - depending on which springs are in your car, you could probably stick in 968 springs and call it a day - or you could go stiffer, but again the torsions will be the limiting factor - i had the uber rare porsche eibach tech/art 150/230 progressives on them for a while and they were great

Tire noise is a funny thing. Out of college, a friend of mine went to work for a tire manufacturer as an engineer and worked in the sound department. Apparently, the notion of "noisy tires" is a lot more complicated than it would seem. Frequency range and repetition make a big difference in how noisy it seems. The part that shocked me was they found that noise perception is also very individual. Some people found certain types of "sonic output" noisy but other louder output less invasive. For other people it was reversed.

Personally, I find them to be about mid-range in the noise department. Michelin sedan tires they are certainly not. But I find them a bit quieter than Falken's top performance offerings and less grating than many of the other affordable high-performance tires. I also have them on my Subaru (every tire is noisy on that car) and really like them at the limit.

On the suspension stuff I'm trying to keep it fairly simple (ha -- NOTHING on these cars is simple). The reason I threw out the 200lb springs is that those are all I've really seen available -- the Weltmeister stock-height ones. I have a set of Tokico D-spec adjustables on the Subaru and I've really had a lot of fun tinkering with the adjustments. I've gotten it down now where I've got slow-speed (<70MPH) and high-speed settings.

I'm by no means any suspension expert, test-driver, or track hound. But, I really like controlling the feel. Right now I've got definitely worn-out rears and trying to figure out where to go from here that will involve less than $1k in parts expenditure.

An alternative might be to just replace my rears with stockers (or good used), get the KLA strut brace, RS Barn lower chassis brace, new castor block and a-arm bushings, new strut tops, and a nice alignment from Clark's.