How can I tell if my Bilstein coilovers have their spindles raised?

[Duc Hunter]

My new project car come with a set of unused front Bilstein coilovers. I know many of these have their spindles raised vs non-coilovers struts, I just need to know how to tell/measure to see if mine have..and if so how much? My part numbers are 35-587736 and 35-587743.

[juanbenae]

not sure about the part numbers, but generally the threaded body billstein struts suited for coilovers are raised 12mm higher than the standard billy spindles. you can raise to a max of 19mm, 7mm higher than the threaded units and still run 16" wheels. there are some spec911's that cut down the strut tops to use the 19mm raise and maintain plenty of damper travel. this however would not be as suitable for coilover use id think.

[Canada Kev]

I believe the spindles on the threaded yellow sport or "RSR" struts are raised 18 or 19 mm. At least mine are. Sorry, but I do not know the measurements of a green strut with stock spindle height. The 18/19 mm raised spindles should allow fitment of 15" Fuchs. However, it is very tight. I can't run my 15s as they are now because the ball joint makes contact with my balancing weights inside the wheel back space area.

Yes, some people will shorten the top of the strut body, but this won't affect the overall length of the strut/damper assembly. As I understand, the top of the strut is cut off with a different wiper installed. This allows the shock to protrude further from the strut body to allow the shock a greater range of motion before the bump stop is compressed fully. This doesn't affect the overall strut length.

Shortening the strut body will allow for greater damper travel without bottoming the shock. This is especially important on a car lowered by indexing or adjusting the torsion bars and not raising the spindles. If lowering only by raising the spindle, damper travel should still maintain the same movement range as a stock car.