Coilovers on E12

Eddie in TO · Post by **Eddie in TO** » Thu Sep 08, 2011 8:56 am

This is all great information...Thanks Jeff!

How's your squatting?
My rear end drops big-time now. I also felt it last year with the M30, but not as much.

I installed the new Bilstein sport replacement rear shocks and switched back to Eibach rear springs from the slightly softer H&R’s. The outcome was just a hair more stiff but it still drops a fair bit according to some friend’s feedback whilst driving behind me.

All bushings have been replaced with new original equipment items. The only urethane I have are the bushings for the ST sway bars.

The spring perch is set at the second level from the bottom and I don’t know if that makes a difference.

I have a new set of Spax springs as well that I haven’t tried out yet. I don’t know if the spring rate is firmer than the Eibach and H&R’s though.

Do you think it’s possible to only change the rear springs for a stiffer pair? Perhaps something from the Eibach shelf?

How about ‘helper’ springs? Is that something that you think would help the situation?

Thanks in advance,
Eddie

scarey · Post by **scarey** » Fri Jul 20, 2012 4:01 pm

Bringing this back from the dead...

Jeff, I was confused by your posts, did you finally end up with a 7 or 8" spring? To clarify further, you did not cut your strut housing?

I have a set of billies that I need to get revalved soon and I'd like to clarify.

Thanks!

YouTube · Post by **Peter Florance** » Fri Jul 20, 2012 4:10 pm

scarey wrote:Bringing this back from the dead...

Jeff, I was confused by your posts, did you finally end up with a 7 or 8" spring? To clarify further, you did not cut your strut housing?

I have a set of billies that I need to get revalved soon and I'd like to clarify.

Thanks!

Make sure they are sports, most likely HD's will not have enough travel.

scarey · Post by **scarey** » Fri Jul 20, 2012 4:33 pm

Thanks, Peter, they are. My understanding, other than valving, the travel is the same it's the bump stops that differ between the two. The HDs having a much longer internal stop.

Dont quote me on that, though.

YouTube · Post by **Peter Florance** » Fri Jul 20, 2012 5:16 pm

scarey wrote:Thanks, Peter, they are. My understanding, other than valving, the travel is the same it's the bump stops that differ between the two. The HDs having a much longer internal stop.

Dont quote me on that, though.

Sports will be fine; if you go way up on spring rate, you may need them to dial in more rebound

scarey · Post by **scarey** » Fri Jul 20, 2012 10:34 pm

I think that I need to decide what my target spring rate is before I ship the Billies off. They are coming out of the car tonight or tomorrow and will be boxed up by weekends end.

I am undecided whether to go with something along the lines of 300-350lbs or 400-450lbs. The car is a daily driver and the roads here in Phoenix are really nice for the most part. It will have to pass the wife test, though. I do plan on autocross and DEs once summer wanes.

I just want to be close so my efforts at Bilstein aren't wasted.

scarey · Post by **scarey** » Wed Jul 25, 2012 10:12 pm

Peter, did you go with shortened strut housings? If so, I will need to come up with a new shock solution. I don't want "moar lowz" (if that's how the kids say it). I want it to handle well and still be streetable first with aesthetics second (or third if your counting).

This is how it sits now, and I'm happy with the height, but it has a little too much rake for me (too high in rear).

https://picasaweb.google.com/lh/photo/2 ... directlink

maxmadill76530i · Post by **maxmadill76530i** » Thu Mar 06, 2014 12:38 am

Hey there, I'm planning on running coil overs on my 530i. I've talked to IE and they say it is not necessary to shorten the strut housings for around 1.5" drop. Is this true? If I were just to weld on a new perch and run seven inch springs what shocks would you guys recommend?

Also what are your thoughts on Billie Sports? Do they need revalving to run coil overs?

Thanks guys

wkohler · Post by **wkohler** » Thu Mar 06, 2014 1:11 am

They don't necessarily need revalving, but the internal bump stops in the front need to be removed. The rear Bilstein sports are valved all wrong (they're likely the wrong shocks in the wrong boxes), and are inadequate for stock springs, let alone coilover springs.

maxmadill76530i · Post by **maxmadill76530i** » Thu Mar 06, 2014 10:34 am

Thanks Kohler,

I guess the question is at what spring rate would you have to revolve. I personally am going for a semi-stiff street setup, maybe 450 front and 350 rear. Does anyone know how much Billstein charges for re-valving?

If my total coil over kit is above $1200 I may just go with ground control. Seems a lot easier and safer as a new guy to these cars. The money will pay off with fun.

What do you guys think about shortening the strut housings? Jeff at IE said that it is not necessary for a 1.5" drop which is what i'm looking for. If I didn't would there be any draw backs?

Cheers

bizz · Post by **bizz** » Thu Mar 06, 2014 5:51 pm

Shortening the strut housing isn't required for the drop you're chasing. However running a shorter insert helps keep everything captive, you can do this and run spacers under the insert to make up the difference. Stock top mounts fit nicely on generic 2.5" ID springs.

As for spring rates, i'm running 392 (7kg/mm) all round and can confirm this is a nice streetable rate. I will have more feedback when I get the car on the skid pan in a couple of weeks

maxmadill76530i · Post by **maxmadill76530i** » Mon Mar 10, 2014 9:26 am

Thanks Bizz,

Would anyone be able to share their costs for re-valving their Billies? I might just go with ground control. It's an extra couple hundred bucks but it would be a lot easier.

Also if I were to run a shorter strut with a stock strut housing is the travel of the strut affected?

Cheers

Danval · Post by **Danval** » Wed Mar 12, 2014 5:44 pm

Great info! What parts did you use from irelandengineering? I got my coil over conversion kit from them for my e30, but i dont think its the same diameter strut. What sleeves did you buy? Also, they dont offer camber plates for e12s. The e10s (2002) fit? Got part numbers? Great post!

JodyStevens · Post by **JodyStevens** » Tue Dec 01, 2015 2:06 am

Just to bring this post back from the dead, I contacted Ireland Engineering about their e12 coilover kit and was told you cannot shorten the front strut housings because the tire will hit the spring. Anyone confirm this? Are there other kits which do allow shortened housings?