Koni Shock Installation Issue

[t36]

Agreed, riding around on the bump stop defeats a lot of the purpose of the shock and puts excess strain on the mounts.
I have a set of the car - I’ll measure later today

[shft22]

I hear you and agree. The interesting part is I have gotten messages from other 944 owners with these shocks and apparently this is the way. Seen pictures from others as well and it shows the foam compressed under normal load.
For what I have been able to research the factory rear shock have a working travel from 11” compressed to 16”, these konis, that many use, go from 14” compressed to 16”
My car currently with the suspension compressed measures 14” from bolt to bolt on the shock mount, so I could really use a shock that compresses to 11” but not these apparently.

[Tom]

I am wondering it they are truly bottomed out at 14 inches, or if they just get much harder to compress at that point. Sounds like Koni's bump stops are intended to provide a progressive dampening effect. From a random reseller: "Koni's cellular polyurethane bump rubbers are specially designed to protect the suspension from bottoming. Like a progressive spring, the bump rubber resistance increases the more it is compressed. This not only provides safe and controlled bottoming of the suspension, but it also prevents internal damage within the shock from metal-to-metal contact."

So I'm wondering if the shock actually has more travel than you think and will indeed compress down a few more inches under actual road forces? As I understand it, these shocks are designed for this car, so seems unlikely they are simply too long? I'd be inclined to install them and drive around. If they are truly bottomed out, I'm guessing it will be pretty obvious and feel like a car with solid bars in place of shocks (at least when hitting bumps). If you poke around, you can find references about Koni's riding at or near their 'cellular foam' bump stops on other cars (e.g., miatas).

[t36]

Ok I measured some older 8040 1035 sport adjustable Koni’s.

A little over 16” from bolt centre to bolt centre uncompressed
13” compressed to the bump stop.


If your car is that much lower, maybe your torsion bar as been re-indexed?

[Damo]

Here some pictures with the car on the ground. As you can see ride height is normal but notice how much the shock extend past the mounting bolt
IMG_8680.jpeg
IMG_8678.jpeg

This looks OK to me. The suspension needs to be able to extend as well as compress so the shock should extend a fair way past the loaded position otherwise the inside wheel will want to lift when cornering.

[AudiSport]

I am wondering it they are truly bottomed out at 14 inches, or if they just get much harder to compress at that point. Sounds like Koni's bump stops are intended to provide a progressive dampening effect. From a random reseller: "Koni's cellular polyurethane bump rubbers are specially designed to protect the suspension from bottoming. Like a progressive spring, the bump rubber resistance increases the more it is compressed. This not only provides safe and controlled bottoming of the suspension, but it also prevents internal damage within the shock from metal-to-metal contact."

So I'm wondering if the shock actually has more travel than you think and will indeed compress down a few more inches under actual road forces? As I understand it, these shocks are designed for this car, so seems unlikely they are simply too long? I'd be inclined to install them and drive around. If they are truly bottomed out, I'm guessing it will be pretty obvious and feel like a car with solid bars in place of shocks (at least when hitting bumps). If you poke around, you can find references about Koni's riding at or near their 'cellular foam' bump stops on other cars (e.g., miatas).

Yes, bump stops are compressible. But it drastically changes your effective spring rate....

[shft22]

Yeah so this is all starting to make sense, the shocks new touches the foam at 14” but after jumping on it a bit the foam compresses a bit.
For what you guys are posting plus Konis email response, it seems the foam bump stop plays a part in the shock normal operation in addition to been a bump stop. Jason from Paragon also said the same.
So yeah I’m taking it on the road and see how it behaves

[shft22]

To close the loop on this. Took the car for a drive and the shocks are working as they should, the car is handling bumps with no issues. Now to the next project, need to look into bushings.

Thank you all for your help.

[CEW]

All great info…and thank you for closing the loop for us that have been following.

[zooklm1]

You have to remove the foam bump stop to adjust the Koni shock. To adjust it, once the bump stop is out, you fully compress the shock and while compressed turn it left or right to adjust the rebound. I think full left is max soft and full right is full firm. This will also let you see the theoretical full compression. As previously mentioned, you really want to put the bump stop back in because it contributes positively to the overall shock performance. I have a fairly new set sitting on my shelf and can take some measurements tomorrow if you like. Let me know.
Lee