DDK - Die Deutschen Klassiker

Hi guys. First technical question for the learned.

I have a 3.2 Carrera that is a very soft ride. Has boge struts up front and Koni rear shocks.
I’ve taken the koni shocks off the back and adjusted them half a turn back from maximum stiffness. Has helped the back a little and stiffened that end up a bit. The front was still soft.
I wasn’t sure if the front inserts were boge or koni (not sure you can tell from the outside) but I’ve sourced a pair of koni strut inserts new old stock. Took the one side apart tonight and it has koni front shocks. Not on the stiffest setting but not wayyy soft like the rear. On3 thing that looked odd was that not all the rubbers supplied with the new koni inserts were fitted on the old shock. Also the spacer ring under the screw down collar wasn’t used. Bit odd?

Anyway. I’m guessing fitting my new koni shocks won’t hurt? I’ve adjusted the new shocks half a turn off maximum stiffness (rod right in and turned fully clockwise until the stop then half a turn back).

Do I fit all the rubbers supplied with the new shocks?

Off to find out how to add images

Cheers

Haith

I have adjustable Koni dampers on my 73 911, basically the same figment.

Front

The longer rubber cushion is in fact the bump stop rubber, the pic on the car is correct.
The 2 rubber rings are for the rear installation. Do not stack the lot together and install on the front!
Set the damping 1/2 way from soft to hard imho.

Rear

Those 2 rubber rings are sandwiched in the rear cross member each damper uses 2 of them.
Again, set the damping 1/2 way imho for road driving.

Hope this helps you.

911hillclimber wrote:I have adjustable Koni dampers on my 73 911, basically the same figment.

Front

The longer rubber cushion is in fact the bump stop rubber, the pic on the car is correct.
The 2 rubber rings are for the rear installation. Do not stack the lot together and install on the front!
Set the damping 1/2 way from soft to hard imho.

Rear

Those 2 rubber rings are sandwiched in the rear cross member each damper uses 2 of them.
Again, set the damping 1/2 way imho for road driving.

Hope this helps you.

Many thanks for the reply. The rear shocks are different aren’t they? They have a ring at the bottom to bolt onto the banana arms directly. The top rubbers for the back fit one inside the other through the shock mounts. One each side. One has a male, the other a female.
It’s the top rubber arrangement that’s throwing me. There was a little piece of paper in the bag of nuts, washers etc with the new shocks. That shows the arrangement I have on the new shock but no explanation of how/where it fits. Or if all supplied rubber rings (the top pair are just rings that slide over a little tube. It looks like way too much rubber to me.

Cheers
Haith

Ok, first, get yourself a Haynes Manual for the 911, available on Amazon etc as this will be a considerable help!

Front;
The long 'concertina' rubber bush goes on the strut shaft as per your picture and the long thin and light dust guard tube slides over it. The long bush is FREE to move where it likes. On compression, the bush acts like a rubber shock absorber as the strut compresses under load.
When you hit a pot hole fast the strut will compress quickly and then the rubber bush takes over and compresses so stopping any 'metal-to-metal' contact within the damper.

The damper insert is clamped into the strut with the large round threaded collar.
Note! you must have the right damper insert in the strut, there are 2 types.
Note! the strut is usually full of an oil, and many think the damper unit has failed and all the oil has come out. Not so. Many inc me fill the strut with the insert 'inserted' with simple anti-freeze.
Fill to about 2" of the top and install the threaded collar and tighten.
The fluid transfers heat generated to the strut outer sleeve and cools the unit.

Probably many do not do this anymore, but I do.

Rear:

As the front really. The round bushes are located as you say.
Again, slide the concertina rubber bush down onto the shaft. Drop the dust guard tube over the shaft, add one of the rubber s and feed into the rear cross-member. Fit the 2nd bush, the steel washer (a big thick one) and tighten the nut tight. It will tighten to a dead stop, metal to metal.

At the lower arm end, the end of the damper eye will not align with the threaded hole used to attach it unless you are very lucky.

If the damper is too short carefully jack the arm up so the fixing bolt will thread into the arm. This can be a difficult fit, it will rarely thread in by hand.
If it is too long then gently push the damper up to align the hole and the arm and insert the bolt. Do this slowly as you are compressing the gas in the damper and it takes time for the gas to displace.

Do the bottom bolts to the correct torque!

IMHO, the 911 is a better road car with compliant suspension, too stiff and the car will be a pain, hence suggesting 1/2 way between hard and soft.

This diagram is off a 914-6 but the suspension is essentially the same.
you can see the assembly sequence.

Many thanks. I have a Haynes and Bentley manual.
I managed to figure it out. All finished late this afternoon. Test drive shows it’s much better now. Stiffer without being too hard. I’m running 15” wheels with 70 section p6000’s so I’m guessing any compliance I’m sensing is down to the taller rubber. Might try a set of 16’s on her and see how she goes.

Good news.
The taller tyres will make a marked difference to general ride quality.
I ran my modified 911 (73T with a 3.2 engine and several suspension mods) on 50 section 'racing' tyres which made the car very direct but quite rough (I drove to hill climbs, raced, and drove back for 14 years in it).
Having retired the car to simple nice weekend road driving the use of simple 70 section tyres has made it really nice.

Very nice.
I have a 3.0SC on 16 Fuchs also and that’s a lot more “sporty” feeling. Tightening up the Konis on my 3.2 has help considerably but riding on the 15’s, it’s still not quite the same. I’ll swap the wheels between cars and see if it’s that the makes the difference.