Porsche 911 struts,sizes, types, inserts and interchangeability

[rockdr]

Forum wise folk

Is there a thread(s) out there anywhere that describes the evolution of the types of struts and strut inserts used on the 911, and also the calipers, ear spacing, materials used, and caliper types?

This information would be extremely useful for some of us trying to upgade or mix and match parts on our cars.

Please let me know if there are any really good informative threads, and i apologize if this ahas been discussed before ad nauseum.

Thanks

larry

[equality72521]

I think the search function will help a lot but many people will chime in here. Maybe this can become the definitive thread on this. Bill Verburg is a great resource on brakes... and more.

[Bill Verburg]

having the years of the chassis and struts you are interested in would help.

Basically from '69 up all struts have either 3" M or 3.5" A/S struts.

Inserts have been Boge, Koni and Bilstein

[rockdr]

Actually Bill V. its all your fault..

Just kidding.

However, after the excellent write up on brakes for early cars that Bill put together, I went on my way to replace my fascinating yet improper "Bremtek" brakes on my 1972 911T - Carrera RS Clone.

I got 84-89 Carrera brake Calipers, a friend had the correct rotors and pads (after a 930 Caliper, rotors & pads upgrade), I ordered new SS braided lines - - and then realized I needed struts with 3.5" ear spacings.

You would be surprised to learn how many people think they can tell you what years and models have 3.0" vs 3.5", etc. However, if you've played with these cars for a while you would not be surprised to know how many are incorrect....(It's like the 6 or 7 books I have purporting to be able to tell you all about Weber Carburetors...)

The other thing Bill recommneded to me was then to get Turbo Bilstein struts, as they were better designed than the struts that were Boge or other inserts.

So I put a post out for thise struts, specifying 3.5" spacing and no one responded. However, a rash of 911 guys said why not use SC or 911 S struts with inserts? What inserts are out there? Wow! There are upside down Bilstein struts ( that are not inserts), there are struts with Bilstein and Boge inserts, there are non-insert original oil dammped Boge's that are incased in the strut housing, and there are apparently Koni's that are not insets. There are inside and outside threaded housings and other wierd upper nut and bushing details......There are green hats and black hats - it's a confusing story for a novice like me....Come to find out, some very early 911's had a plate for the calipers that bolts on the the strut in an even different way.....

Add to that my more knowlegeable friends start mentioning that you should take the plug weld out of the spindle collar, and raise it up on the strut - -how much - -?18mm? Then you can decamber the spindle? Yikes!


So, I'm willing to be the "pimp" to try and get enough info so in the future we can have a chart, resource article on our hosts site, etc., so that someone can come and look up what they have and see where it could be interchanged - -and reven possibly find out for example if someone (i.e. the infamous "Previous Owner") put something different than original on, and what might be a sequence of logical steps in an upgrade - - not to mention RSR struts, etc....

So Many folks know a heck of a lot more than i do abot this - give us some ideas how to organize this.

BTW thanks so much for the incredible help and patience the members of this forum have with those of us less knowledgable.

Larry Boyer
AKA Rock Dr.

72 RS clone (in progress to vintage racer)
74 911
87 944 ITS Race car
86 Audi 4000 CS turbo DTM clone
1990 S2 replica
1990 Audi 90 Coupe Quattro
02 Cummins Turbo Diesel to haul the **** around with ....

[rockdr]

Come on you guys & gals ...don't be shy....lots of lookers with no posts...

If you have info on this please send me stuff - -

I'm willing to put it together as I work on my own project.

Larry

[Bill Verburg]

I'm not quite sure what you are looking for
Bilstein struts are the ones that are upside down, this reduces unsprung weight.

There are Bilstein inserts for non Bilstein struts but they are upside down from a Bilstein strut and don't reduce unsprung weight.

All oem Bilstein struts from '73(Green housing) are the same and have the 3.5" axial caliper mounts, the inserts damping characteristics differ according to model

Some of the earlier cars have Koni(orange housing), i believe that these were only used on the S or Carrera models and will have 3.5" caliper mounts, there are also a bunch of oddball T & E so equipped either oem, dealer or by a PO.

The more mudane cars used Boge(black housing) which could have either 3" or 3.5" caliper mounts, you have to measure

the Bilstein RSR come w/ raised spindles

'66 -71 used a slightly different strut which I'm not at all familiar w/ Chuck Moreland at Elephant can help you w/ those.

[Flieger]

Paging Chuck Moreland:

I have a 1971 911S with original Koni orange front struts. I have new yellow Bilstein dampers in the rear.

What is special about the 1971 Koni struts?

[micheloaks]

Hi Bill
can you advise as to whether Konis (ext. adj) with part number 8611039 sport will fit a boge strut. original fitment to my 67 912? Help appreciated. Regards Michel

[4flyboy]

Hey Rock Doc,

Great idea. I'm bewildered by these questions on my own car and riveted to this thread and it's outcome. I believe that this is exactly what Wayne has in mind for his new PelicanWiki permanent data base.

Good luck and thanks,

Scott

Bump

[RWebb]

maybe the thing to do for the pimping you said you were willing to do is to create a table of what strut, insert, r. shock came on what year & model 911.

you could then add part no.s, links to pics and etc. and rebound, etc. data

but I got nuthin' on that

just this little tidbit:

Gas –pressurized Bilsteins were used for the first time as standard equipment on trhe '73 RS and saved 7.7 lbs. Adler 1998, p. 39.

[SCWDP911]

Can someone clarify something for me on this topic please?

I have a stock (pretty certain) 83 cabriolet. It definitely has the Boges. As some might recall, I had a recent incident involving a deer and construction pylon that resulted in a bent driver's side front strut housing. I am currently searching for a replacement. Someone thought they had one to fit my car, but in the end, it ended up being a PAX side housing. They mentioned the 3.5" spec. My question is, is there a simple answer as to what year front driver's side strut housings will fit my car as a "stock" replacement?