The lack of height adjustment on the OEM Konis shock absorbers means I am replacing them with adjustable QA1s.
As many others have done, I am trying the US-made QA1 PromaStar shock absorbers combined with Eibach springs. The shock absorbers required for the 308 are the DS-402 for the front and DS-502 for the rear. I am using 375 lb/in springs at the front and 325 lb/in at the back. The rear spings are softer even though more of the weight is back there, because of the suspension geometry. The front shocks are steeply angled, needing a stiffer spring, compared to the rears almost vertical springs, to support the weight of the car.
Both models are lightweight aluminium-bodied shocks that generally get good reviews when fitted to the 308. In the box along with the shock body are the lower perch, upper collar and some eye bushings (which are the wrong width for the 308’s suspension).
First of all, to make adjustment easier when the shocks are supporting the weight of the car, I also ordered the optional roller bearings and adjustment wrench. The roller bearings go between the spring and the lower perch to allow the perch to rotate more easily while under pressure from the spring.
The QA1 shocks also needs a couple of modifications to fit a Ferrari 308. Both front and back shock absorbers need alternative bushings to match the length and diameter of the original Konis bushings. The replacement bushings were sourced from the Unobtainium Supply Co.
For the front suspension, the standard QA1 shock eye inteferes with the upper suspension arm. This means either the suspension arm or the shock eye must be modified. Unobtainium Supply Co sells a shock eye that is extended and shaped to avoid any interference with the suspension arm.
The replacements are significantly sturdier and better quality than the QA1 ones they replace. The QA1 shocks have removable eyes so changing the standard one is simple.
The shock is assembled in the following order:
- Shock body
- Bump stop
- Lock nut
- Lower perch
- Roller bearing
- Upper collar
- Extended shock eye
Installing the bump stop is probably the most awkward part of the whole process. I don’t know why QA1 choose to make the hole in their hard rubber bumpstop 1/8″ smaller than the diameter of the rod but they do. A little WD40 and a lot of force got the bump stop on.
To ensure the shock will remain adjustable after it has been fitted to the car for a while, the lock nut and lower perch need to be installed after a coating of anti-seize.
With the anti-seize applied, the lock nut, lower perch and roller bearing and washers can be installed.
A 10 inch spring is recommened with the DS-402 shock which means that it needs about half an inch of preload applied before the coller and eye can be installed. An external type of spring compressor can be used to apply the preload.
However using a regular spring compressor means there is not a lot of room for the hooks between the spring and shock body. With the spring compressed the upper collar and extended shock eye can be installed with some thread locker applied.
With the shock eye fitted, the spring compressors can be removed and the shock assembly is complete.