Lowering spring rear perch question

Blaise · Post by **Blaise** » Thu Oct 06, 2011 12:59 am

I am installing a set of Eibach pro lowering springs.

On the front, they went on without a hitch and slightly tensioned in the assembled strut.

On the rear, there is about a 5/8" gap between the upper perch and the top of the spring.

I have done some searching on this site and understand that this is not really a problem once the car is under load.

But I also understand that many tie the spring to the perch. This makes sense to me, as it would prevent the spring to perch relationship from changing when the car is jacked up. I would prefer not to have to worry about that later on.

What is the preferred method to take car of this? Any photos?

I am not interested in bringing up the lower perch (Bilstein HD), as I want to take advantage of the lowering the car some.

Thanks in advance

Pete K · Post by **Pete K** » Thu Oct 06, 2011 10:57 pm

I used a couple of cable ties top and bottom.

If you want a top class job, you can get the Bilstein's rod shortened.

Cheers

T.Hanson · Post by **T.Hanson** » Fri Oct 07, 2011 9:09 am

I have (old) Eibachs on two 528's. Never heard,"Pro," added, either because old and used omitted the word or they are making new that fit.

One set uses Bilstein Sport shocks with three lower tube circlip perch slots. The bottom two work well for no spring flopping.

The second set uses HD shocks, only because I thought they'd work and Sports, for rear, are harder to find. HD's only have one lower perch slot. Right on the edge of loose with the lowering spring, won't allow the car to sit as low as the Sport shock.

For future reference, Is fooling with Bilstein for rod shortening, shock modifying a long and spendy process ? I.e., to make the choice easier to just find and buy new Sports ?

Pete K · Post by **Pete K** » Fri Oct 07, 2011 10:03 am

I've never got a price. I asked Bilstein in Australia about it when getting a price for rebuilds of my fronts and it was $400 for the rebuild with 1" shorter rod. That was in Sydney back in 2008 though.

Eric Q · Post by **Eric Q** » Tue Oct 11, 2011 12:00 pm

T.Hanson wrote: For future reference, Is fooling with Bilstein for rod shortening, shock modifying a long and spendy process ? I.e., to make the choice easier to just find and buy new Sports ?

I just had some E23 rear HDs shortened and it was easy. Just get a copy of their order form on the website, fill it out and send it with the shocks. I actually delivered the shocks myself to their shop in Poway (go to Will Call in the back) since I live only a little over an hour away. It took about 2-3 weeks. All they did was rework (or replace, I'm not sure) the internal piston. I also had them add 4 grooves on the shock body so the spring perch can be adjusted.

Just tell them you want the shock to work with a 30mm shorter spring and tell them to add 4 grooves about 10mm apart below the original groove. It only cost me $150 for the pair (they guy told me he was giving me a good price, I don't know if I got a deal or not) since I was not revalving the shocks, which were brand new.

For the E23s, they did not have an application for "Sport" so they didn't do any revalving. I don't know if the same is true for E12s. They told me in some applications HD and Sport valving is the same (this is true for E28s). The HD valving seems to work fine with my Dinan springs.

Eddie in TO · Post by **Eddie in TO** » Wed Oct 12, 2011 8:12 am

I used the same Eibach springs and Bilstein HD shocks for over ten years and I never had them come loose when it was on the lowest setting.

I have the same scenario with my latest suspension setup with Bilstein Sports and the Eibach springs. The springs are a hair loose on the second lowest setting when the vehicle is raised off the ground.

If you’re not in a hurry, I believe Bavarian Autosport still offers the Bilstein Sports for a great price. The only drawback is that you may or may not receive them with the correct pressure. If you don’t, you can send them to Bilstein under warranty and they’ll correct them or send you a new set (if they have anymore in-stock). Josh and I have experienced this. The turn-around is approximately 1 month from the time you send them in, they dyno test them, and send you a replacement.

I’ve confirmed with Bilstein USA that the pressure is different between the E12 HD and Sport models unlike those offered on the E28’s (same pressure).

Blaise · Post by **Blaise** » Wed Oct 12, 2011 12:00 pm

I just wired the spring to the perches. Now the lower perch can float, without the springs rotating relative to their seats.

<table><tr><td><a href="https://picasaweb.google.com/lh/photo/3 ... site"><img src="https://lh4.googleusercontent.com/-a-zQ ... G_3116.jpg" height="640" width="478"></a></td></tr><tr><td>From <a href="https://picasaweb.google.com/1030509870 ... site">1977 530i upgrades</a></td></tr></table>