IHI

It has been a while.
The Mazda ended up in a corner of the workshop, had a turbo fitted and meanwhile I bought a Porsche Boxster to do the holiday trips with. A bit more comfort. Great car, but I miss the little tweakable and agile Mazda.
So I picked up the good work and decided to get the Mazda back on the road.
I took out the Koni shocks and they are shot. 2 leaked and had air bubbles floating trough the valves (the rear). Not too bad, but leaving them on and it will get worse.
One of the front shocks is broken though. The adjuster is stuck. And the amount of rebound is INSANE. You cannot pull it out and it takes a couple of hours to have it pushed back by itself. This is more or less what I felt, the front was jacked down and making the whole car feeling super stiff. I don't know why I did not notice it was just one shock that was shot, but it might be the ARB that helped out.
Anyway, I requested a new set from Koni.
Let's see what their warranty is good for.

Now I have this set of threaded sleeves and springs that will get on to the new Koni's.
Front: 375/7"
Rear: 250/8"
The question is this:
If I fit these and put the ride height at about 12.5-13", would I have to preload the springs ? I don't wan't the springs to get loose as the car wil fail for its annual technical checkup.
In that case I would need helper springs. Could anyone having a similar spring setup advise please ?
I wan't to put this set together once I have new Koni's, and I wan't to have it right the first time, this time..

Second question: Why is there a nut welded to the front shock body ?

IHI

To answer my own question:
Yes, I do need helper springs.
At 13" ride height the springs are loose for a good 2".
This way the car will fail it's annual technical checkup.
And I have a little problem.
I calculated I needed 7" front and 8" rear spring.
This would work. But not much spare room in the sleeve.
I probably cannot get the car much lower as the perch is at its lower position on the sleeve.
I might even need to rework the shock to lower the sleeve another inch, depending on the size of the helper / tender combo.
But then it would be close to the upper A arm. Depending on the helper spring compressed size this would make little room for further lowering the car.
Why in the world is there so much droop in this car. I would trade some droop for bump travel. And I am talking 13" here.
I might just put the whole set for sale if I get new Koni's and buy some Xida's.
Are the Xida's shorter and offer more bump travel over the Koni's ?