Designing the S60R suspension

Its well under way now.  I'm expecting to have all CAD drawings out for quote before the night is over.  The goal is quite simple.  Avoid designing everything from scratch by using the most expensive parts from another company that is meant for another car and modifying where necessary to build an S60R specific damper set.  I want a rebuildable custom tuned set of dampers including rear spherical shock mounts (if you need them) for around $1,700.  If I can add a rebound adjuster and still hit that target I will make it part of the standard package.  If I can't then it'll still be an option.  The strut clevis is designed for adjustable camber so you don't need to spend more money on camber plates.  I am also planning on giving the end user the ability to customize the damper further if he/she feels the need (different ride heights, different spring rates, different damping curves, more adjuster options from the Penske parts bin, etc.)


The design specs are as follows for the front strut:

  • Off the shelf damper cartridge with 6" of available stroke.  Way more than needed but I'll take it!  This design is inverted and is therefore much stronger/stiffer and has less friction than 22mm shaft struts like the OEM and KW.
  • 46mm main piston with rebuildable shim damping.  This is quite large and will provide good response with lower internal pressures (less friction).  I'll be receiving the dampers valved for another similar car and rebuilding them with my own S60R specification on the Roehrig shock dynos at work (Penske Racing Shocks if you haven't figured it out yet).
  • The provided DU bushings (what guides the damper cartridge and takes bending loads) are not of sufficient quality.  I will be using the same DU's and seals Penske uses.
  • Each cartridge will be disassembled, cut, and rethreaded to a specific length.  The goal is to maintain 6" of stroke with an overall length 1" shorter than OEM.  That means, unless you specifically ask not to, these will lower your car.  The initial spring package I'll be testing will leave around 4" of compression stroke and 2" of rebound stroke with around 1" drop in ride height.  Bump rubbers will be included.
  • The cartridge has to fit in something (a "strut outer tube") that mounts to the S60R upright and that doesn't exist.  I'm finalizing the design tonight on a outer tube to house the DU bushings.  This tube is also what the clevis ears are welded to which will be welded by an ex-Penske Racing Indycar chassis fabricator.  Should be good'nuff.  This strut outer tube will then be black electroless nickle plated for long term corrosion resistance and sexiness.
  • 2.5" ID Hyperco springs

The design spec for the rear shocks:

  • Full Penske Racing Shock build based on the 7500 series coilover.  Volvos shouldn't be riding on Penskes but that is why this is an awesome project.
  • Whatever adjusters end up on the strut will be on the rear damper
  • I do not yet know what the solution is for the rear spring.  The OEM upper mount is a PIA.  I want to use off the shelf linear Hypercos so I'm hoping I can make an adapter.  If not, custom wound springs aren't that expensive but it'll make it more difficult to provide different rates.
  • I'll update this with the available stroke, don't have that info in front of me.

I can't fully fund everything necessary to build up stock before making these available for sale.  I will be running a group buy with a large deposit required.  I'm thinking $700 will keep it to serious buyers only.  I do have at least 5 already saying they're committed.

Needless to say, I'm extremely excited.  Once the first design is complete I'm not sure how far this will go.  It won't be difficult to change a few things and adapt the shocks to different cars so keep that in mind if you reading this and you are in need of some quality dampers for your new R-design or old 850R.

If you have any questions/feedback or would like to express interest please feel free to email me at pdvmotorsports @ 

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  • Hiya , how is the shock research / build going ?
    Also I would like to know is it would be possible to rebuild an original 4’c shock by anychance?

  • What is the latest update on these?

    S60r on
  • Awesome!!! Super excited to see where this is going!!!

    Mike portler on

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