Note: performing any of the modifications discussed below will likely void the Bilstein warranty, so keep that in mind.

I've talked with a few people on here about shortening the damper bodies of Bilstein PSS coilovers and thought I would post an update to the topic...

There is about 1" of unthreaded material above the spring perch threads on the front and rear damper bodies of the PSS system. With my set, I had ~7/8" removed from the top of the damper. There is approximately 1/8" of unthreaded material before the spring perch threads still remaining.

After rebuilding one of my dampers last night, I checked the clearance of everything and was bit surprised to see that the piston almost covers the piggyback orifice when the shaft is at it's far extent of compression travel. If this were to happen, the pressure would build very quickly in the main tube and potentially blow a seal.

So, if you are considering having the rear damper tubes shortened, please leave about 1/4" of material above the spring perch threads on the damper body. Running a bump stop (everyone should be using bump stops) will help ensure the piston never covers the piggyback orifice.

The front dampers do not have this issue, as they are much longer. The 7/8" removed from them is fine.

 

A fix for the rear is to shorten the shaft as well as the spacer above the piston to regain any loss in stroke.

 

Very true. My initial statement was based on leaving the piston/shaft/spacer assembly alone and only modifying the damper tube. Thanks for bringing this up.

 

Is this anything I need to worry about? Im getting PSS and the ride height will be barely one finger gap over the tires.

 

nothing to worry about

 

Yeah you definitely need to shorten the shaft anytime you cut down the damper bodies.

 

Though it's close, I wouldn't say it's completely necessary. Recommended...maybe.

Even after seeing how close the piston gets to the piggyback orifice, I don't plan to shorten my damper shafts. There would have to be some very obscure loading to cause the shaft to bottom out, which is highly unlikely.