For Anyone with Bilstein B6 Shocks:

[Katech_Zach]

For anyone with Bilstein B6 shocks that has had a negative impact on ride height and ride stiffness after install:

The rear shock compresses the OEM spring roughly ~0.50" more than stock, causing additional preload on the spring. This effectively raises the spring rate and makes your rear end stiffer. This will also raise your ride height depending on how stiff your spring is.

The solution I came up with was modifying the Bilstein rear spring perch to drop an additional 0.50" on the snap ring seat. I also turned down the O.D. to match the OEM rear perch. Hopefully this helps anyone that has had similar issues.

[olblue75]

Zach is this something a average guy can do in his garage or does require some speacial tools?

Interested in a set of B6s now that are available again and I'm sitting on 1 inch drop springs.

[Katech_Zach]

Originally Posted by olblue75

Zach is this something a average guy can do in his garage or does require some speacial tools?

Interested in a set of B6s now that are available again and I'm sitting on 1 inch drop springs.

If you have access to a lathe, I would say so. You don't need to turn down the O.D. like I did.

If you don't, any local machine shop should be able to do this no problem.

[xc_SS/RS]

Originally Posted by Katech_Zach

If you have access to a lathe, I would say so. You don't need to turn down the O.D. like I did.

If you don't, any local machine shop should be able to do this no problem.

If someone was to purchase the B6 shocks/struts through Katech could you offer this as an option?

[Matty Ice]

If it is compressing the spring, wouldn't it lower the ride height? Or is it because the spring rate increases then the spring doesn't "sag" as much? This might explain why I didn't get as much as a drop in the rear as I did the front. I am on BMR -1.25/B6's. Thinking about switching to DSE springs.

[Katech_Zach]

Originally Posted by xc_SS/RS

If someone was to purchase the B6 shocks/struts through Katech could you offer this as an option?

We have no plans to do suspension at the current time unfortunately. We will not be able to offer this service. The most I can do is to inform the public of my findings.

Originally Posted by Matty Ice

If it is compressing the spring, wouldn't it lower the ride height? Or is it because the spring rate increases then the spring doesn't "sag" as much? This might explain why I didn't get as much as a drop in the rear as I did the front. I am on BMR -1.25/B6's. Thinking about switching to DSE springs.

It will raise the ride height. Think of it this way:

Your car's corner weights are fixed variables. The same amount of force is going to be applied to the spring assuming everything stays constant. If you were to raise or lower the spring perch, it is going to raise or lower the ride height of the vehicle. In our case, the spring is being compressed more, so it will take more force to further compress the spring than it typically would.

This results in the ride height being higher than it should be (and the spring rate @ ride height being higher).

I think your drop will be fine if you modify the shock and verify that your suspension is not bound (re-timing bushings).

[olblue75]

How did you move the perch down?

[Katech_Zach]

Originally Posted by olblue75

How did you move the perch down?

You have to throw the perch in a lathe, indicate the snap ring step in so it is perpendicular to your boring bar. Then you set your zero.

Afterwards, you proceed to cut into the part in slow passes until your ring step is moved .5" inwards (or whatever amount you measure it to be off). In my case, it was roughly 0.5".

[olblue75]

Thanks for the info Zach but if I'm running 1" drop springs there's no need to do this correct???

[Katech_Zach]

Originally Posted by olblue75

Thanks for the info Zach but if I'm running 1" drop springs there's no need to do this correct???

Any spring that is meant for the OEM shock/spring perches will require this modification if all the Bilstein shocks were as off as mine were. Your spring will still have additional preload that it does not need.

[dfwRobert]

What upper shock mount was used. Base SS, 1LE or something else.

[Katech_Zach]

Originally Posted by dfwRobert

What upper shock mount was used. Base SS, 1LE or something else.

OEM SS 1LE. I believe they are the same throughout the model years. The Z28 may be the only different one but I am not positive on that one.

[dfwRobert]

Thanks for responding. In your pics it looks like the bottom perch is mounted correctly in relation to the bottom of the shock where the bolt goes through. It is the threaded part up top where the length is goofy.

Apparently the 1le shock mounts are different than the base SS. I know people have said they look similar but is where the threaded end mounted deeper or more shallow? I have never seen 1le stuff side by side on a bench for comparison. Doubtful but If anyone has both rear shocks and could get a pic of a 1le shock and SS shock side by side like in Zach's first pic to show the threaded end difference that would be awesome.

If the two stock parts are different maybe that would explain some things. Maybe Bilstein has some incorrect stuff or maybe they modeled the shocks after an SS non 1LE test car.

Sorry to bump this old thread. Just really interested in the Bilstein's.

Thanks

[Cheap Guy]

Wow. This is interesting information given the number of people who waited to get them after being out of stock for so long. I’ve used Bilsteins in the past on all my other vehicles so this would be an interesting and unusual issue for them.

The 1LE mounts are definitely different than the regular SS mounts according to all the stuff I read before I installed my 1LE stuff. I really didn’t notice any difference in threading but I really wasn’t looking that close, but the swap to 1LE shocks/struts from SS was basically plug and play except for the rear mount.