Bilstein Shock Question
 

My shop is a Bilstein dealer, and looking at the Bilstein site there is a ton of different options for replacement shocks. I have yellow Bilsteins in the rear of my '80 911 and they feel so stiff over bumps that I'd like to replace them with something softer. I daily drive this, no track.

Anyone know the part number for the softest rear Bilsteins? From what I've read, the green ones should soften it up - 24-001694. Any other input?

https://www.bilstein.com/us/en/product-search/?YearId=5986698419897221299&MakeId=662504048008285 3653&ModelId=2519919736562830481&SubModelId=472128 6252877769428

Thanks!

rear
yellow are Sport
Rebound/Compression
220/180 N@~.52m/s

green are hd (24-001694)
Rebound/Compression
195/151 N@~.52m/s

Appreciate it Bill. Can you elaborate quickly on what the numbers mean in real time? the 195 would be softer than the 220? Or am I backwards?

I just put green HD bilsteins on my 88 911. Very happy, not too stiff. I also found it very confusing and hard to find the HD for both front and rear from the same place. Listings can be confusing.

Here is a screenshot of my invoice of what I got.

http://forums.pelicanparts.com/uploa...1643158705.png


Bilstein part #'s off of the boxes

Front for boge: 34-001142, P36-0114
Rear 24-001694, B46-0169

Thanks! Unfortunately, this invoice doesn't show the actual Bilstein part numbers to reference. What shop is this from?

Edited my post with part numbers from the boxes. Came from vertex.

correct, the #s are the resistive force as measured on a shock dyno @ the specified speed

lower #s are softer

HD is softer than sport

Perfect, thanks guys!

I'm sure y'all ran into the same things by googling...but..

https://www.pelicanparts.com/catalog/SuperCat/0804/POR_0804_SUSSHK_pg2.htm

Passenger car

Search around for digressive valving...You can have Bilsteins revalved with much more modern internals that will give you a reduced compromise between ride quality and motion control.

If you're gonna go through the effort to replace 'em, you might as well improve the tech by a few decades...

How low is your car? Stock Bilsteins on a lowered car are basically riding on the bump stops. The oil filled adjustable Koni 1159s has a shorter body which puts a lowered car in the center of the shock travel. At full soft they are a game changer. Even with 21/27 torsion bars on my SC targa, I put 17k miles on last year with no discomfort.

B8's are for lowered cars. As I understand that is the only difference in B6 vs B8.

If I remember correctly, the B6 is for pre-1989 911 models, the B8 is for 964/993 models.

"Normal" shocks in the 911 means either Boge/Sachs or Koni (and some Woodheads) shock absorbers, Bilstein was always the "sport" option, this means the "normal" B6 shocks (all green).
But Bilstein offers far more shock absorbers with different settings, and they're all far more stiffer stiffer than the "normal" green ones. I see you have a Targa. Here in germany most of the owners of convertibles & Targas recommend not to use anything stiffer than the green Bilsteins (sport option), some of them go back to from Bilstein "sportlich Strasse"/"sporty road" to stock Boge/Sachs absorbers (the softest and stock with no sport option) because the body of the car suffers too much over time...Kayaba also proivides shocks for the 911 G body cars, they're a stock replacement (no sport option), in the rear for all G body cars, but in the front only for Boge struts available:
https://i.imgur.com/YdX1HtF.png
They're worth a test.

All Bilstein shocks for G body are B6 (what I know). The colour on Bilstein is not useful to separate the shocks, only on the back: Green = Bilstein stock replacement = Porsche sport option, Yellow = Bilstein sport (any!). Boge/Sachs do not offer sport settings for the 911G from what I know. B8 are for coil over replacement.

Also be aware about the different meanings on "sport options" here:
-Porsche stock (no sport option) => Boge/Sachs/Woodhead
-Porsche sport option => Bilstein B6 (all green, but Bilsteins stock setting)
-Porsche Club Sport => also Bilstein B6, but stiffer setting, all yellow, this is one of two settings Stefan Rosar figured out on the Nordschleife in the "Yellow Bird"
-Bilstein "sportlich Strasse" (front green, rear yellow) => far more stiffer than "normal" Bilstein, often recommended here in Germany, but more and more go back to "stock" Porsche sport option (bilstein all green) or even Sachs/Boge...

Please refer to the Bilstein catalogue (the 2019 version linked here is the only one which contains most of the settings): https://www.bilstein.com/de/wp-content/uploads/2020/01/4_BILSTEIN-Klassik-Katalog-2019.pdf
See pages 46 and following for Porsche, the values for the settings


And here's an overview I created last year about the different settings of Bilsteins:
https://www.pff.de/thread/2794625-erfahrungen-mit-fahrwerk-von-kw-variante-3-fuer-g-modell/?postID=155619585#post155619585

Regards, Thomas

Thomas, thanks for the info, that is very helpful.

I have B6 shocks installed on my '82 SC, it is also lowered and I get a "clunk" noise periodically that I have believed to be from the shocks. These are new shocks installed last year and suspension was adjusted lower at the same time. Through this thread and my own research I have read that since my car is lowered that I should be using the B8 or the Koni 8210-1159 (reply #12 from shoooo32).

According to years of PP topics on the clunking phenomenon, it is generally believed to be the shock bottoming out when going over more harsh road bumps on lowered 911's.

Can anyone confirm that these other shocks will eliminate the clunking noise?

Also, I have not be able to locate a B8 rear shock. Does Bilstein make a B8 shock for the rear? I have found the Koni's easily, so sourcing them is not an issue.

TIA

From where do you hear/feel that noise? Front or back?

In back, in the shock mount area.

Broken sway bar holder?

Nope, everything is new and refreshed. The only conclusion I have been able to come to is the B6 shocks are bottoming out on harsh bumps. I'm likely to try a set of the Koni's.

I have some of the same questions about the B8. I am refreshing my suspension and adding 21/28 torsion bars. I called Bilstein directly and they told me that although the B6 would be fine, the B8 was more suitable because my car was lowered. I went to order them from our host and was surprised to find that they only make B8 inserts for the front with no B8 rear shocks. So the question is on my lowered 911 SC, if I use B8 front inserts, which rear shocks do I use? I called Bilstein directly again and unfortunately spoke to a rep that was less knowledgeable than the first. They could not give me a goods suggestion for rear shocks. Any thoughts?

Even w/ the b8 fronts regular rears have always been spec'ed
24- 1670 are the green hd used for Carrera and 930
24-009751 are yellow sport
24-009676 are yellow club sport

they become stiffer as you go down the list

w/ 21/28 t-bars I'd use either of the last 2

Thanks very much, Bill. That’s great advice. Mystery solved. I will probably go with the 9751 for the rears.

B6 should be fine. For the past few years, I have had Bilstein Sports on a lowered 84 with a little stiffer bars. While it's afar from perfect for perfectionists, good enough for my street, light track use. If you really care, Bilstein can custom valve for you to shave another 0.02 sec off your lap times.

Well, as a follow up, I solved my mystery, but it's not an impressive story. As a friend of mine once said, "never underestimate my ability to outsmart myself". That pretty much sums this up for me.

I was determined to get this "clunk" sorted out once and for all. So today I went under the car and checked everything out to see if any of the suggestions made here might be the cause. Well, none of the scenarios described applied....so I decided to remove one of the shocks....this was when my stupidity was put on full display. I forgot to separate the two rubber bushings at the top of the shock, so both we under the shock tower instead of one on top and one on bottom. Soooo, with that fixed I took her out for a shakedown drive. PROBLEM SOLVED!! Despite it being a self inflicted "clunk", I am glad I at least found the issue before I spent money on replacement shocks. So, although my car is lowered (not slammed), the Bilstein B6 shock works just fine, doesn't bottom over harsh bumps (like I had previously surmised).

You're never too old to learn....thanks to all PP'ers who gave me plenty to think about and helped lead me to the solution.

Tx, what are these rubber bushings? My shocks have a clunk and I can't remember having seen rubber bushings other than the big (end of travel?) one on the skinny part of the shock.

Although my shocks were green, not yellow, this is a pic of the two rubber bushings. They have a steel sleeve that connects them, through the body of the shock tower. One stays on the shock and inserted up into the shock tower, the other is placed back on to the shock shaft with the fender washer and nut.

http://forums.pelicanparts.com/uploa...1644119725.JPG

Tx, Thanks for your help! This is the Bilstein B6 inserts I used. I left the rubber bits where they were. Were they mean to be on top of the strut where it goes through and into the hood area?

http://forums.pelicanparts.com/uploa...1644127964.jpg

I just had 2 Bilstein front struts apart, and the rubber goes at the bottom inside the strut housing, as shown in the picture, right top. That's the bottom section.

Glad you found it! We have all made similar errors, thats how you learn. I could write a book on my own! I have gotten into the habit of taking pictures of everything while I am working. I use the camera on my phone more than the phone. Great when I forget my readers :) Sucks getting old.

Thanks, yep, that's the way I have it. But is there meant to be a rubber bushing at the top too?

Depending on your ride height , the bump rubbers need to be either fully discarded or cut in half .
If you do not tend to this you could run the front suspension at full compression hense the handling and ride will suffer greatly. It's all about the travel of the shock based on the T bar stiffness and ride height.

Ian

I want to piggyback on here if I can. According to the previous owner my car has bilstein sports all around. They'd be at least 40k miles and 12+ years old. 4 years ago I put in 21 and 30 tbars, new rubber elephant racing bushings everywhere and had it corner balanced and aligned at lower than euro height. It's probably a bit too low. I find the ride borderline. I knew I was going stiff with the tbars, but it's mostly used on fairly well maintained mountain roads. I love the handling but larger bumps are a bit painful sometimes.

I'm replacing tires and thinking of raising my car a bit closer to euro height. If I'm going to raise, align and cb it again I guess I may as well do the dampers too. It's a 2700lb m491 with 17inch 8.5 and 9.5 wheels (225/45 + 255/40). Stock sways. Would B8 hd fronts and b6 sport rears improve the ride of a lowered, lightened car with stiff tbars or is it just the nature of the tbars?

Also, I find the 21/30 ratio bars give me fairly neutral handling with mild oversteer when I want. If I soften the front dampers will it be a big change in that regard or is it more the springs and sways that determine the handling balance?


http://forums.pelicanparts.com/uploa...1644216872.jpg

When I removed my old inserts, the bumpers were totally trashed. Probably from age and the low ride height of my car. My car is very low, definitely below euro height. How do I know how many (if any) bumpers to use?

for the "Turbo" strut inserts no rubber at top. actally there is never a rubber at top. it would quickly compress and desintegrate. that's what the strut tower mount is for to absorb.

the ribbed one at bottom can be cut in sections (3, 2, 1)
lightweight and lowerde sports cars can use 1 of the three.
A regular car should keep 3

mine is slightly lowered and lightened a bit. I use 2

http://forums.pelicanparts.com/uploa...1644127964.jpg

Thanks Flo. I'll set my SC ROW to 2 also. Good to hear re no bushing up the top.