Guidance Needed on Addressing Ride Height on '78 928
05-31-2014, 03:00 AM
#16
Rennlist Member
Can you say a little more about what needs to be swapped from the S4 for the Eibach rears to fit?
In my case, I only needed to switch the front springs to accomplish ride height objective.
Rear ride height was adjustable within the range of the rear bilstein adjustors that were on the car. But I wanted to install the rear eibachs too at some point and didn't realize there was hardware needed.
In my case, I only needed to switch the front springs to accomplish ride height objective.
Rear ride height was adjustable within the range of the rear bilstein adjustors that were on the car. But I wanted to install the rear eibachs too at some point and didn't realize there was hardware needed.
06-01-2014, 11:49 AM
#20
Drifting
Harvey,
I read you've already ordered springs but for future rennlisters doing a search..
Here is a photo of the S4 front springs (fresh paint)
purchased from 928 INT next to my dusty originals taken off the '83.
Note: they did not come from 928 INT repainted.
My originals measured about 14-5/8", the S4s 13-1/4"
They fit perfectly in the perch.
The S4 spring looks to be a slightly less robust spring as well as a bit shorter.
I read you've already ordered springs but for future rennlisters doing a search..
Here is a photo of the S4 front springs (fresh paint)
purchased from 928 INT next to my dusty originals taken off the '83.
Note: they did not come from 928 INT repainted.
My originals measured about 14-5/8", the S4s 13-1/4"
They fit perfectly in the perch.
The S4 spring looks to be a slightly less robust spring as well as a bit shorter.
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Terence (01-24-2024)
06-01-2014, 03:16 PM
#22
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Some interesting tidbits I've harvested over the years.
-- I spent some time with the Eibach guys shortly after I got the car, but working on a different project. I casually asked what they had for the 928. At the time, they were private-labelling the Weltmeister springs, and working on the 928 International set based on the KJC design parameters. Bottom line is that the Weltmeisters are Eibachs in label disguise.
-- When Mark had a group batch sale on Eibacks several years ago, I bought a set thinking that I'd be able to use them to restore some front ride height lost as the original springs sagged. I installed all four with new standard Boge low-pressure dampers. The front adjusters are at max full height with the Eibachs to keep the car at 175mm front height. The ride was way too harsh for DD use on our undermaintained freeways here. But I did enjoy the much flatter handling on my personal backyard mountain road course. I then bought a set of very slightly used GT/CS front springs and similarly aged rears from DR. I ended up with the Eibachs in front, and the almopst new factory rears as a compromise between the teeth-rattling ride and the flatter cornering. It's the best compromise so far.
-- The '78 weighs noticeably less in front, and comes with longer springs and a very slightly different front control arm geometry compared with the S4+ suspension that the Eibachs are designed for. That's in addition to the different mounting setups for the springs on the Bilstiens vs the original shocks. The difference in length is multiplied by tthe geometry to decide final ride height. I'm interested to see the difference in length original vs Eibach, as well as the final ride height difference.
-- I spent some time with the Eibach guys shortly after I got the car, but working on a different project. I casually asked what they had for the 928. At the time, they were private-labelling the Weltmeister springs, and working on the 928 International set based on the KJC design parameters. Bottom line is that the Weltmeisters are Eibachs in label disguise.
-- When Mark had a group batch sale on Eibacks several years ago, I bought a set thinking that I'd be able to use them to restore some front ride height lost as the original springs sagged. I installed all four with new standard Boge low-pressure dampers. The front adjusters are at max full height with the Eibachs to keep the car at 175mm front height. The ride was way too harsh for DD use on our undermaintained freeways here. But I did enjoy the much flatter handling on my personal backyard mountain road course. I then bought a set of very slightly used GT/CS front springs and similarly aged rears from DR. I ended up with the Eibachs in front, and the almopst new factory rears as a compromise between the teeth-rattling ride and the flatter cornering. It's the best compromise so far.
-- The '78 weighs noticeably less in front, and comes with longer springs and a very slightly different front control arm geometry compared with the S4+ suspension that the Eibachs are designed for. That's in addition to the different mounting setups for the springs on the Bilstiens vs the original shocks. The difference in length is multiplied by tthe geometry to decide final ride height. I'm interested to see the difference in length original vs Eibach, as well as the final ride height difference.
06-02-2014, 03:25 AM
#26
Rennlist Member
Nice work, Harvey. Love that silver car.
Question for the suspension guys -- in what S4 year did the springs change to a smaller diameter substrate? 86.5? 87? After?
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Question for the suspension guys -- in what S4 year did the springs change to a smaller diameter substrate? 86.5? 87? After?
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06-06-2014, 09:14 AM
#28
Rennlist Member
Thread Starter
Got the car back yesterday from alignment (sans camber since I am putting Eibachs on). The car now tracks straight ... steering wheel is straight ... rides awesome. Looking forward to getting the springs on and getting rid of the SUV look!
BTW - I will be at SITM but won't get there until around 2:00 due to a PCA Meeting that I had committed to.
BTW - I will be at SITM but won't get there until around 2:00 due to a PCA Meeting that I had committed to.
06-15-2014, 03:27 PM
#29
Great thread! Glad you made it for SITM, Harvey!
So, the non-adjustable ride height springs where longer than the later springs, but IIRC the spring rates where not that different?
By cutting one of the older springs for use in a ride height adjustable setup (S4 setup) one would get a stiffer spring. This might not be too bad?
Anybody tried this? Any feedback from guys with Bilstein and cut older springs?
So, the non-adjustable ride height springs where longer than the later springs, but IIRC the spring rates where not that different?
By cutting one of the older springs for use in a ride height adjustable setup (S4 setup) one would get a stiffer spring. This might not be too bad?
Anybody tried this? Any feedback from guys with Bilstein and cut older springs?