IPD HD Rear Overload Spring Kit, w/ bump stops - P3 XC70

Generally speaking, we like the rear suspension design of P3-chassis Volvos like the XC70, with the multi-link control arm setup providing good roadholding, minimal camber change, and nice comfort, all while being fairly easy to work on and upgrade thanks to its separate shocks and springs and easy sway bar access.

That said, we're less fond of Volvo's active bump stop design on these: the spring's location halfway along the control arm between the wheel and the rear subframe center only provides an inch and change of suspension travel before it hits the bump stop, which then acts as a helper spring past this point to add to the spring rate before the shock absorbers bottom out...

...which works well enough, until age and the elements and repeat cyclic loading cause the foam rubber of the bump stops first to lose their elasticity and eventually crumble away altogether. When carrying moderate to heavy loads, your car's ride will go from stiff to bouncy, as you crash in to the ends of shock absorber travel.

Volvo's reliance on the bump stops as a source of secondary spring rate rather than as an emergency backup for big jolts also means those bump stops wear out that much faster, especially if you haul a lot and end up using (and using up!) the bump stops more regularly. 

IPD has engineered better springs to resolve this once and for all, with a progressive spring carefully matched to loaded and unloaded ride heights: the dual-rate 220lb-in / 300lb-in spring provides stock ride comfort with light loads, and only adds extra stiffness as you load the car's rear end up to the point where you start to get noticeable sag.

Also included are shorter P3 S60 / V60 bump stops with this kit to replace the XC70's original taller bump stops, providing an extra inch of spring-only travel to make the increase in stiffness with sag more of a gradual curve rather than a jarring step. In the words of our spring engineer, "the spring rate increases towards infinity" when the bump stops kick in, so we've done our best to keep this from happening at all.

Additional Keywords: HD HEAVY DUTY