GF04RCE

Hi There,

I have acquired a set of Bilstein B6 dampers/shocks and wanted to get some new springs.

The more I looked, researched and read the more confused i got.

Current setup is standard, but fronts have been cut down which is causing some issues on the big bumps.

My car is a 1985 S2 RoW 16v Manual

When i enter my car details with retailers it comes back blank. Where i did find options the price came back very very high. The general forum view appears to be 300lb fronts, 200lb rears for good all around fast road use. Progressive springs ok if you only drive on brand new roads, if like me your daily drive is pot holed country lanes then go linear springs

I now have a confusing range of springs and am not clear what the standards should be or the spec i should be looking for 😩

Rears on my car are: 400mm/16 inches, 120mm/4 1/2 inches diameter 9 coils
Rears on bought used Bilsteins (used on a 1980 car) : 420mm/17inches, 130mm/ 5 1/4 inches diameter 9 coils
fronts on bought used Bilsteins : 320mm/12 inches, 140mm / 5 1/2 inches diameter 6.5 coils

Generally Coil Springs are not expensive, therefore there must be a standard spring out there that is used on another vehicle that is a close match to the requirements of the 928. So that is my question:

What Coil Spring options are there for the 928 front and (even rarer) rears?
What other cars have 300lb springs or 200lb springs, that could be used on a 928?
What will best compliment the Bilstein B6 for general road driving?
Is there a table out there of years and spring specifications?

I have had some WSM info that 1984 to 1986 should be 340mm springs (fronts i guess but no back spring data)

Thanks in advance for any ideas....

David M
1985 S2 Manual - on jack stands getting under carriage stripped refreshed and cleaned.....

P.s I may just end up re-coating the stock springs i have (not the cut down ones) and see how that goes, but would prefer to buy new.

Bigfoot928

What not to do....

https://rennlist.com/forums/928-foru...-than-oem.html

SMTCapeCod

Stock spring variations are identified by paint stripes on the coils- if they are still there. I thought BILSTEINS matched with green stripes...but could be wrong and there are certainly variations among model years. Info would be in Tech-specs books and probably elsewhere on this forum or online.

The Forgotten On

Originally they did. The springs were different lengths compared to other 928 springs when Bilstien were the sport option because unlike the normal shocks, they were high pressure gas filled and not low pressure oil shocks.

The lengths of the Bilstien ones became the standard when the BOGE shocks became high pressure gas filled as standard. So you can fit standard S4 springs to get the correct height of the car.

The original springs on an early car will make it sit high about 2 inches.

GF04RCE

Hi Blake,
Thanks for the steer towards the S4 springs...... Do the S2 and S4's use the same diameter cups or will I need to get a new set front and back?

The 2 inch impact might explain why the fronts were cut down and the rears were adjusted right down on the used set I bought....

Cheers

David M

SMTCapeCod

Additional Refs:

https://rennlist.com/forums/928-foru...ng-length.html

https://rennlist.com/forums/928-foru...t-springs.html

Aftermarket was more or less Eibach and H&R, and 928Intl had a specially spec'd version of the Eibachs but NLA.

mkhargrove

85 16 valve.....just curious...what is the date of manufacture on your sticker? mine has "1985" stamped on it, but the vin says it's an 84.

GF04RCE

I'll have to check...

GF04RCE

Thank you, this was exactly the information I was looking for.....


There is very little information on rear springs it looks as though they may have stayed the same length from S2 to S4 @ 415mm unless anyone knows any different.

David

Johnny G Pipe

In response to this, with the help of this forum I realised that this was mainly an operator error issue - I neglected to fit the lower washer in the assembly of these coilovers.

Yes they are adapted to fit the 928 but my mistake aside, have been pretty good, they fit well, they are light, inexpensive and have good adjustment possibilities. But they are at the fast street/track end of the comfort spectrum - my understanding is that they have been used in transaxle cars in race series over here with good results.

https://www.gazcoilovers.com/porsche...gha-p-405.html

No affiliation, and yep if I did it again I would agree with your choice and fit likely Bilstein like I did to my 964 and 911SC. Sorry to hijack and not address your question.

GF04RCE

Checked my sticker no mention of 85, there is an 840510 number that looks like it could be 1984 5th October which would correspond with the 1st registration date.

David M

jpitman2

840510 in Euro form would be 84-May-10th, not October, assuming its a Euro sticker. If its a US affixed sticker, maybe, but I would have expected it to be in US form as 051084.
I have M474 Sport suspension Bilsteins, and the ride is firm over poor surfaces, but terrific on the open road. Look for Greg Brown;s opinion on this set up - something like 'absolutely the best suspension '.
jp 83 Euro S AT 57k

Wisconsin Joe

Your VIN should be WP0ZZZ92*S8... The asterik is the year. "F" would be 85, "E" would be an 84.

Also, what kind of fuses do you have? Blade fuses are 85, "GBC" fuses are 84.

It doesn't really matter all that much. An 84 S2 is essentially the same as an 85, at least as far as springs & shocks go.