Landseer

928 Intl sells front Bilstein, one model good for all years.

Footnote says -- can be used on 78 thru 84, but you need to use the short springs from later cars.

Did springs change beginning 85?


Did the shocks or the adjuster collars change from the original sport suspension Bilsteins installed on my 84 car?

( the replacement shocks are already on the car, recent, probably same set as 928 Intl is selling --- but ride height has been awfully high --- trying to sort out options here)

Landseer

Hoping I can use 84 springs.
I have 86.5 springs too, but they measure the same length.

Here's the bilstein dimensions I'm working with.

jheis

I originally had fixed height (non-adjustable) Bilsteins on the front of my '82 with the "competition package." One of the shocks failed & I had to replace them with height adjustable Bilsteins (like you have).

With the stock springs, the front ride height went up about an inch - even with the adjusters cranked all the way down. I was told that I had to use S4 springs with the height adjustable Bilsteins. Installed a pair of Weltmeister S4 springs & problem solved.

The WSM is not much help on this matter, using "tolerance group" rather than length to identify the various springs.

They do say (page 40 -49) that:

"Springs with approx. 200 N more force at a standard test length (e.g. tolerance group II springs as opposed to group I) increase the height of the front axle by approx. 5 -15 mm."

It goes on to say that:

"If Boge dampers are replaced by Bilstein dampers .... the front axle is raised by approx. 10 mm because of the gas pressure in the latter dampers."

The WSM recommends the use of the "white/green" springs with the Bilstein front shocks.

Don't know if this helps. It was kind of trial by error for me. The Weltmeister "S4" springs worked fine, but I ultimately did the S4 front suspension and brake conversion on my '82 (mainly for the brakes).

James

Mrmerlin

I wasnt aware that there are different spring lengths but rather different spring tensions fitted to different years for AC and non AC ,
the markings are different color stripes on the springs,
both springs should have the same color striping

Landseer

James, thanks for that info, explains what I'm finding.
Stan, I thought the same, maybe its rates not length.

84 has three green stripes.

86.5 parts car with std boge ---somewhat corroded springs. don't see stripes.

Am in process of shifting to full later suspension, was going to keep 84 sport springs.
Now, not so sure. Probably need to use the later ones.

Maybe I can use the 86.5 springs and also whack a coil or two off to get the low ride height I'm looking for.



BTW, Bilstein collars are brand specific, very different from standard collars.
And it appears Bilstein front are different than back.

I also need to replace the front Bilstein adjusters, cut off last weekend.

soontobered84

The non adjustable front springs are longer (read: have one extra coil) than the adjustable front springs. I think what Intl is saying is that you must use the adjustable front spring length when using the height adjustable Bilsteins else your car will look like a U-boat. (high in the front compared to the back)

Landseer

Do you know what year or model had adjustable springs, that is, with one less coil?

I've got 84 3 stripe originals next to 86.5 originals and they have same coil count.

Must be I need later ones?

Landseer

The 86.5 springs in my garage have 3 brown marks.
The 84 Euro springs have 3 green marks.


Plenty of confusing info in the WSM, as-referenced by James (above) --

Looks like I'd be better off with softer white/green, though the measurement is made at a different compressed length.

Time to improvise. Not sure how. Maybe whack the brown ones and hope for the best.

LT Texan

Some have cut a coil off the stock spring.

Tom in Austin

Is it correct to conclude from the WSM excerpts that all cars from "86 onward" have brown springs, since Porsche went to Boge for both std and M474 applications?

I started a spring rate thread last week and Roger pointed out that GTs had optional sport springs, but all other S4 and newer in USA were same spring rate, IIRC ... now I wonder if the GT sport springs are in the 1,2 or 3 brown grouping for "86 onward" ... or maybe some other color category?

soontobered84

No. You have springs from an adjustable front end. IIRC, '84 is the year that Porsche went to adjustable height front.

85euro928

Landseer,
What are your ride heights? The reason I'm asking is that I have the same set up, Bilsteins w/ 3 green marks on the springs. My ride heights are 165 front (with the adjuster all the way down) and 170 back, but my ride height in the front still "looks" to be about an inch too high. In speaking with the group at Frenzy the consensus was that maybe the front springs had been changed at one time or another but I took the shocks off and sent them back to Bilstein to be rebuilt and there was no sign they had ever been taken apart. I'd really like to get the front down if possible and am hoping you find an answer as I didn't.

GlenL

...on all 928s.

Simplified: If you've got non-adjustable front shocks then you need the later springs.

Landseer

Not sure of the ride height, its getting the S4 A Arms and brakes right now.

But here is the stance, front settled, adjusters nearly fully down.

soontobered84

I am running Konis on all my cars, but your ride height "looks" to be about an inch higher than my '89 which has stock springs and has plenty of adjustment room left to be lowered. Any possibility that you have the adjustment nut upside down on the shock?