Flamblocs Welded In

New Ferrari Flambloc Bush

The front suspension flamblocs have been tack-welded to the front suspension wishbones. Flamblocs are a particular type of flanged, rubber ‘silent block’ bush that connect the wishbones to the suspension forks at the bottom and chassis at the top:

Location of Ferrari Flambloc Suspension Bushes

Each flambloc is made from two concentric steel sleeves with a bonded rubber substrate in between that acts like a torsional spring. The outer sleeve is welded to the suspension wishbone and the inner sleeve is fixed to the fork or chassis at each end via a bolt run through the center. When properly fitted, the only moving part is the rubber layer which stretches to allow the two metal to rotate independently:

Ferrari Flambloc Cross-section

A literal cross-section of an old bushing can be seen here showing the two metal sleeves and the internal rubber filling. Ferrari have used them on virtually all of their road going car’s supension systems since the 70s. They provide a firmly controlled geometry without being overly harsh. They work well but two aspects are critical…

Firstly, the outer sleeve must be tack welded to the wishbone. If it is not, then the outer sleeve will itself rotate inside the wishbone, wearing the wishbone and eventally causing it to fail.

Secondly, the inner bolt can only be torqued with the bush in its final position and under its normal load. If it is not, then when it does rotate to its final position, the rubber will be under undue stress in what should be its neutral position which will lead to premature failure of the rubber.

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4 Responses

  1. Paul says:

    Nice write-up but you don’t have to load the suspension to torque the bushing bolts. Just get the suspension arms level and then tighten them up.

    • David says:

      Paul, that would be true if I was using the existing springs and shocks. However because I am lowering the car a little on new adjustable shocks and stiffer springs, I have no idea where the wishbones are finally going to sit. So the plan is to not tighten them, lower the car, set the ride height, let everything settle and then tighten them.

  2. max says:

    Polyurethane bushings are easier to fit, don’t need to be welded or torqued under load.

    • David says:

      Hi Max, I had poly bushes on the car before this… while what you say is true, they also squeak and I, personally, don’t like how poly bushes work… as the suspension moves, the bushes actually wear, no matter how well lubricated. To me, that is a design flaw. Ok for a race car being rebuilt regularly but not a road car. There’s a reason manufacturers do not put poly bushes on new cars… even when they are cheaper than rubber.

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