Bilstein racing shocks

[911pcars]

I've tried to research Bilstein's description of their racing shocks with 220/180 valving. How does this translate into compression/rebound rates.

I'd rather not wade through several Bilstein docs, but will do eventually.

https://www.ebay.com/itm/NEW-Pair-Set-of-2-Rear-Bilstein-Motorsports-Shocks-For-Porsche-911-Racing-Only/153305132765

Other than the built-in comp/rebound rates, what else makes these unsuitable to be rebuilt/adapted for street use? These have a 4" shock travel. I'm looking specifically at the spherical bearing bottom mount.

Sherwood

[Cory M]

The numbers represent DN (DecaNewtons) at a speed of 0.5 m/s, rebound first and compression second. So 2200N rebound, 1800N compression at 0.5 m/s.

I wouldn't worry about the spherical bearing, it still has rubber at the top mount. You may have to buy some adapters to mount to the trailing arm, Rebel Racing sells these shocks and should have what you need if the stock bolt isn't enough.

more info, and comparison to the standard sport and HD shocks here:
Question on Bilstein shocks

[911pcars]

Cory,
Thanks for the link.

I'm specifically looking at the bottom spherical bearing as a solution to using shocks with alloy suspension arms. So racing shocks are a backdoor solution.

There's an angular alignment difference between the lower shock mount and the threaded mount in the control arm. Rubber deflection is needed to insure the M14 bolt engages the threads (without cross threading). Like hydraulic shocks, but moreso, gas shocks (e.g. Bilstein) provide enough overall resistance to not allow an easy, finger rotation M14 bolt entry into the control arm. A spherical bearing has enough angular range to not make R&R an adventure.

The option is to either revalve a used racing shock or to add a spherical lower mount to new or used street Bilsteins. Using coil overs (at this point) isn't an issue. In both cases, revalving services is a push. The rest is variable (labor and bearing quality).

Any other thoughts/strategies?

Sherwood

[Cory M]

I've got spherical lower mounts on the JRZ shocks on my racecar. It uses a longer bolt and a small spacer on each side to allow for articulation of the spherical bearing (pic below). I think revalving would be easier than adding a spherical. You could also use a universal double eyelet shock with the shock clevis adapters that Tarett sells, but they may just be adding cost and complication.

Tarett adapters: https://www.tarett.com/items/911-products/911-suspension/911-shocks~springs/shock-clevis-adapter-pr-rsrsca-detail.htm

[911pcars]

A bump, fwiw.