The Bilstein rear shock has a ring to adjust the height in steps.

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Pictures from PMB website

In order to increase the accuracy of the adjustment one would have to install those threaded adjusters which are sold as coil over shock kits (even though the 914 rear suspension is coil over shock by design but that is a different discussion...).

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The question is this one: Is there a threaded adjustable setup that can be used with my set of Weltmeister 140lbs progressive springs which fit in the standard perch (to my knowledge)?

Seems to me all that would be needed is a perch that could fit on that adjustable nut, or am I missing something?

The short answer: No.

The long answer: The springs that go with those threaded adjustable spring perches are smaller diameter than the stock springs, while the Weltmeister springs are the same diameter as the stock ones. You could have someone make up a spring perch that goes over the threaded one that could support the wider springs.

I only know of a couple of the threaded spring perches, and I believe they use the smaller-diameter springs. Someone may know of other ones, though.

--DD

I don’t understand the question.

There are currently three options.

1) Stock fixed perch. Least expensive. Satisfactory for at least 80% of the 914 market. Good

2) Bilstein adjustable perch with finite adjustment. Better

3) “Coil Over” with infinite adjustment and spring diameter sized to typical aftermarket race springs. Good for competition, unusual street applications not easily addressed via #1 or #2, or for those with an abundance of money that just want to look cool at Cars & Coffee. Best

Why would a vendor tool up to make a 4th option that is a tweener between #2 and #3 for a tiny market segment? While it is possible to make a fully adjustable “coil over” that utilizes stock spring diameter, the question is why bother?

Yes, you could make a perch to fit Weltmeister springs to the option #3 parts currently in the market. But keep this in mind, the perch will have to be thicker to resist the bending / deflection that will be generated by having the spring seat outer diameter further from the damper center line. You may run into issues with spring length or coil bind due to the physical differences between stock or Weltmeister springs and springs the “coil overs” were designed for.

I went to my local salvage yard and found pipe collars to fit over the the threaded part of the adjusters. I had to hog out the threads to make them fit and cut them to 1". The collar fits on top of the adjustment ring and the spring perch sits on top of the collar.Click to view attachment Click to view attachment

Interesting solution.

It looks like the stock spring OD isn’t too much larger OD than the “race” springs? Nice to see the picture since I don’t have parts right in front of me.

Very clever, a spacer!

That is exactly the type of answer/solution I was looking for!

Thank you!!!

Thank you. That is what this forum is about, sharing knowledge to make our cars perform.

Geezer, did you already have a Ground Control or similar system on the rear? The gold anodized collar looks like their component. I’m unclear how you incorporated that with the salvage parts. Can you elaborate just a little more?

Thanks!