Auto_Werks 3.6

Why does no one list a Bilstein HD insert for the turbo or S2 model. They have one listed for the NA and they also list the NA shock for the 968... which I would have thought would be similar spring and weight to the turbo. I will be using the car for TRACK ONLY but my limitations are: not adjustable, not rebuildable, and not more than 2x the cost of a stock replacement part. I have access to a shock dyno, but I'm not super keen on ordering one of each insert on the market to compare them. Any advice welcome

MAGK944

Probably because the front inserts are only replaceable on the na's up to 86. All the MY86 and prior na's had a screwed on flange on the front struts that allowed the removal and replacement of the insert. Later cars are sealed units so the inserts cannot be replaced. Koni has a front strut insert for the later cars that they worked around the issue by cutting the strut top off and reattaching the new insert from the bottom. Bilstein don't have anything similar.

The Bilstein HD rears will fit your car and all cars from MY 85.5 on, including the 924S and 968.

If you are really determined to have Bilstein HD inserts at the front you could always buy some MY86 or earlier strut housings and fit the Bilstein inserts into those.

Auto_Werks 3.6

Will the '86 struts work on a late offset car?
I wouldn't mind the Koni's but they are adjustable, which I need to avoid.

I wonder why they say you can use them on the front of the 968? did they go back to serviceable struts, or is it maybe a typo?

Thanks

beamishnz

I had Bilstein HD inserts in a late 944S. I'm pretty sure they are listed in the full Bilstein catalogue.

I then ran the same struts in an S2 I still own but upgraded the S2 to Bilstein Escort adjustible platform and gave the HD set up to the guy who purchased my 944S.

I'm a big fan of the Bilstein HD but you need to make up a threaded removeable cap for the stock sachs strut body. I'll attach a pic of mine. That is quite a hassle, so most folk go for the koni inserts which again require cutting of the sachs strut but are bolted through the bottom so don't need welding.

I personally would endure the hassle and go for the Bilstein but there are many on this forum who prefer the Koni so now you have a choice

Here is a link on how to do the Koni conversion

https://www.paragon-products.com/kb_results.asp?ID=50

The HD Bilsteins are valved for sports road use. The Konis have adjustable damping and on stiff may be more suited to track than the HD's. unnles you had the Bilsteins revalved but now you would really need to be a Bilstein loyalist





Late 944 Sachs strut converted for Bilstein insert





Koni insert conversion

Auto_Werks 3.6

I did some more reading, and the early strut won't go in the late car... Seems like the knuckle dimensions are different

Beamishnz, do you basically cut the top off an early and a late damper and add the early top to the late bottom via welding?

JacRyann

I've successfully used Bilstein HD inserts on later cars with two different methods.

1. The early NA struts have 20mm spindle clamp and the later cars, 951 and 968 have 18mm. I made a simple 2mm shim with two big holes. Also have to slot mounting hole as spacing between them is different. Other issue is the angle of the two holes don't allow as much camber if you have '87+ car.

2. Cut off top of sealed struts and weld on threaded section to use gland-nut. Google "sectioning struts", this is done in just about every other make from old Datsun Zs to Miatas. Be sure to measure the lengths of the two sections before welding.

Both ways works equally well once it's completed.

beamishnz

JacRyann has basically answered this. The preferred option in my mind is to weld on top section and thereby retain full camber angle adjustment at the bottom.

A lot of suspension shops are familiar with this technique. You can use either early donor struts or I believe some VW and Audi struts have the same diameter and correct thread. Or you could simply have thread cut to end of some tube of correct diameter. JR is correct of course that you are careful to maintain the correct overall length.[/QUOTE]

MAGK944

I cannot see anywhere where they say this, can you post a link. The 968 doesn't use serviceable struts. Maybe you are confusing the rears with the fronts.

Which series are you running that doesn't allow "not adjustable & not rebuildable"? I can understand the not adjustable part but if you cannot run rebuildable you are somewhat restricted to the stock 87+ Sachs/Boge strut.

Also on the not adjustable what exactly are the rules? Is this just a restriction on height adjustable struts or does it apply to bump/rebound adjustments. Need more specific details to advise correctly.

beamishnz

I think he is referring to a Bilstein listing that has whole strut assemblies for a 968 NA ... if they do they would fit a late 951/944. I'll have a quick look at the Bilstein master catalogue.

beamishnz

Looking at the Bilstein on line catalogue they do list an insert for the 968 with Bodge but they don't note that it needs to be modified as described above to rebuild. I think that is a catalogue error.

With regards to non adj regs, it would def be worth checking if they are really referring to height adj. Normally damping adj would be permitted in most series if available on stock shocks.

Auto_Werks 3.6

weeeelll, we're going to use it for chump car. I'm sure about the rules limitations. been running a first gen rx7 and did some quick calcs on the 951 and i think we can be competitive even with the penalty laps for the Porsche

beamishnz

I'm a huge fan of Bilstein but for your application and for ease of installation I'd go for Koni if it meets the regs. Otherwise Bilstein and info above gives you what you need to go down that route.

JacRyann

If you want lowered-height without bottoming the strut, you can use an '80s VW Scirocco Bilstein insert. It's shorter than the 944 insert, so cut the housing accordingly.

beamishnz

Cunning!

Olli Snellman

Chuck out my thread "young man's first Porsche" there's information how To convert late model sealed strut for Bilstein insert.