Hi everyone,

It's time to R/R the shocks on all four corners. I'm at a dilemma on choice between the foll:

Bilstein/Eibach
Koni (Internal Adjustable)/Eibach
Koni (Internal Adjustable)/Hypercoil(DEVEK)
Koni (Internal Adjustable)/Stock Sport Springs

Comments appreciated....!

Thanks,

 

I just installed Bilstiens about a month ago.

To say that they kick total *** would be a massive understatement.

 

Each responder will donate a different opinion - a lot depends upon what your driving style is and on what sort of roads: In a twisty rural area, I have Konis in both cars. The '80 has '85 euro S springs, and the S4 has stock '2 brown' stripe springs. I would like to try the GT sport springs on the S4, but it's pretty nice as is.

 

Thanks Garth,

I should have qualified the above with "the car is a daily driver that sees some DE now and again"

I also do not mind a bit stiff, as long as it is not too bad in the rain. I will also be going to 285/30-18 on all four corners..

 

Dont forget the leda option over at the racers edge. That setup would compliment all your other high-tech additions.
Hans

 

the S4 is heavier than the earlier years. i found the eibach springs quite stiff on my 86 but not overly stiff at all on my 88. i went from factory sports springs on the 88 to eibachs and i would say they are only a modest but worthwhile difference. id get the most substantial shocks i could afford. on my 86 i am installing hypercoil springs with eibachs, will let you know what i think when they are on the road!

 

Hey Garth,
you mention "85 euro S springs" and a mechanic once told me i have row springs on my 85 euro. So my question is what is special about the springs on an 85 euro?

I know europeans like a more firm ride, what specifically is different about euro springs??

 

Same question. What's different about the S2 springs?

-I'm in the same situation as Richard; I noticed some "weeping" from my front struts the last time I pulled the tires to clean the wheel wells, and I've decided to change out the struts. I'm going to do the springs as well, just for good measure. Think about it: they've been supporting 3300 pounds since April 1985 = 20 years and 3 months. I'm sure they've sagged a bit since! My car handles well, but rides like a rock in my opinion, not that I care.

Anyway, I've been thinking about Bilstein/Eibach the past few months. I changed the springs/shocks to Bilsteins/HoR on my previous car, a VW Corrado, and the difference was utterly amazing! The car was athletic but fought you before; Afterwards it was like my 928 is now: you don't consider speed when you approach a corner- you just brace yourself and turn the wheel, the car takes care of all the fuss for you! That's not a function of car, because properly tuned Corrado's keep up with 928's on autocross circuits. Though I know that the difference in handling with new springs/struts will probably be less obvious on this car...I'm still wondering what is the best route. Autocross? I'd like to try that, though I think the best thing for me is a setup that is biased towards a good, hardcore street ride. Autocross implies all sorts of changes to the car such as removed equipment, poly bushings...etc, which I don't intend to do. At least in my current thinking. I don't care if it rides real damn hard, as long as it does what it is supposed to.

Sway bars? Drop links? Do I need these?

N-

 

"-I'm in the same situation as Richard; I noticed some "weeping" from my front struts the last time I pulled the tires to clean the wheel wells"

LOL normy, you got it bad...

 

Richard,

I suggest going with the Bil/Eib package. The Konis are adjustable on rebound to adapt to differing springs. Can lead to excessive fiddling better spent making electrics work. Or get the externally adjustable. Reports are that the Bilstein shocks have better street manners and Konis are better for the track.

The Hypercoil set-ups require additional hardware as they use 2.5" springs instead of 4.25". (May have those diameters wrong, but you get the idea.) This would be a better track approach with the Konis as there are a huge variety of springs available in that size.

tv, normy, et al,

Checking my handy Tech Spec booklet, there is no appreciable difference between springs up through 84.(Don't have an '85 book) The springs are grouped by rate and put in as a balanced pair. Before height adjustments, the rates were allocated by A/C or not and by left/right hand drive. Apparently this was done to match vehicle weight better. The book says nothing about RoW or engine model being used to select springs. Maybe '85s get stiffer units?

Norm,
Swapping in new sway bars is attractive. Or getting "steroids" to effectively stiffen the ride. Not sure aout the necessity until you're getting serious about tracking the car. Drop links with ball-joint rod ends instead of rubber are a good step as well.

 

I can't say specifically what the spring rate is on the set installed on the '80; however, they came from a 310 hp 16v Euro with Bilsteins - two green stripe IIRC. I find this car exceptionally well balanced and responsive with this combo
I've another set of these (2 x green) in the garage from an identical '85 310 hp. They were to go in the S4 for a trial if I could find any comparative rate data to the S4 2 x brown stripe units ... like 10% stiffer, etc. Anyway, the '80 if noticeably firmer than the S4 with identical shocks. Perhaps that is merely a function of the weight difference as drnick noted .... I haven't been sufficiently motivated to swap them over, only to confirm that the only difference is a heavier car ....

 

Thanks Garth. I noticed when i was cleaning in the wheel wells the color stripes on the springs and have seen the stripes when people post pics of their clean suspensions. Anyone know if these colors or stripes mean anything?

 

I have had the bilstein/eibach setup for about 1 year and love it. Even with the switch to 255/35/18's in front and 295/30/18's in the rear, I find the ride firm but comfortable. The car is much more controlled in it's damping over bumps and no longer "wallows" through the corners. Perfect for a street car with the occasional autocross or track day. Hope that helps.

Jim R.

 

I'm also sitting on this fence. I think my stock 88K mile suspension is okay for now, but it does wallow a bit too much over bumps. I'm thinking a set of 18" wheels all round maybe 255's up front and 285's in the rear with a bilstein/eibach setup would be ideal for me!

 

I think I've got it now...

The stripes are used to group the springs by a measured force. There's a 10% difference between the very stiffest and the very softest so not a big deal. 1 stripe is soft group, 2 stripes medium and three stripes hard group.

While the groupings by force are the same for the 80-84 springs, the length at which the mesurement is made is different. Porsche groups the springs by the force the spring produces when compressed to a given height. This is a good way to measure the real spring rate and get springs that will have the car even with the non-adjustable spring plates. The later springs, with green stripes, are measured at a shorter length (191mm) then the earlier springs (211 and 217mm). So, while they were going for the same force the later springs are either shorter or softer. I'll go with shorter, and a bit stiffer, as the adjustable spring mounts sit up a bit higher than the plain spring plates. I bet it would make the older car handle better.

Someone, somewhere, measured these. Anyone?