[bgregg]

2.5" ID coilover 425 lb/in Eibach springs, bump stops, camber plates, height adjuster, plastic camber slider reinforcement, O-rings, stickers, allen key. Very brief instructions re: top of camber plate.



Comparison to Eibach Pro-kit front spring (for comparison, not part of kit):

[bgregg]

2.5" spring adapter plate

[Liquidpaper]

Set looks beautiful. So tempting...

[bgregg]

It is interesting to me that those little 5" inch front coilover springs do the same job better than the 9" lowering kit springs!

Regarding protecting the bearing race from strain as best as possible, I was thinking since I have several floor jacks...I could jack the car part way with one floor jack. The use a second floor jack under the bottom of control arm area to get the wheel off the ground. And change from street to track wheels that way?

[bgregg]

One more photo, which sums up the kit (pre-install):

[rwalker]

Originally Posted by bgregg

It is interesting to me that those little 5" inch front coilover springs do the same job better than the 9" lowering kit springs!

Regarding protecting the bearing race from strain as best as possible, I was thinking since I have several floor jacks...I could jack the car part way with one floor jack. The use a second floor jack under the bottom of control arm area to get the wheel off the ground. And change from street to track wheels that way?

Sounds like it'd work, but I think GC should have a recommendation for you.

[Pparana]

Originally Posted by bgregg

It is interesting to me that those little 5" inch front coilover springs do the same job better than the 9" lowering kit springs!

Regarding protecting the bearing race from strain as best as possible, I was thinking since I have several floor jacks...I could jack the car part way with one floor jack. The use a second floor jack under the bottom of control arm area to get the wheel off the ground. And change from street to track wheels that way?

Linear spring vs progressive hence coil difference. let us know how that behaves with the stock struts since they are designed for progressive.

Bmw goes through considerable lengths to tune the struts, that's why all quality lowering springs keep the same progressive rate. What you have there is unfortunately the worst of both worlds, springs are linear, which is better for track, worse for comfort, struts are tuned for progressive so they will not provide the proper dampener curve for the linear spring, prob leading to some unpredictable behaviors on track.

[bgregg]

Pparana makes a good point about spring matching with damper matching. I did something on prior car that I hated afterwards, in my autocrossing days. Questionably good for autocross, but terrible for daily driver! I have always liked refined suspension designs of BMW and Porsche. Not looking to kill that.

One question: Were the rear springs linear all along? They sure look linear design to me. it is certainly possible to put a Koni or Bilstein damper in, unless I missed the point. I was going to let the OEM dampers wear out before upgrading them. I've used both Bilstein and Koni struts on prior cars, and it would seem they would work with this kit (later on). Maybe sooner than later, knowing myself?

I went pretty "conservative" on spring rates trying to keep some street comfort. More aggressive setups might actually use 440 lb/in springs front, and 700 lb/in rear, for example. And a more aggressive setup would certainly have to match up with a better strut, agreed. This is still a daily driver car for me.

My install is on Monday. My first test drive will be mountain windy roads with some definite suspension travel requirements involved. So I will be able to report something back in a fairly timely manner. I guess the main questions are:

1. How difficult or straightfoward was the install?
2. How does it drive? On street? On mountain/canyon roads? On track?
3. Will the camber plates (bearing race) stay intact for a long time?

[Pparana]

I'm not trying to be negitive, it's just when I see linear springs I figure someone is after race car handling, happy to give up the comfort. Then when I see coilovers I figure corner balance, or ride height. Leaving the stock shocks sort of negates the physics of the whole operation unless for looks.

kW and blisten both use progressive springs with there plug and play systems and all the way up to club sport I believe.


The spring rates you have are Mildly aggressive, if the struts can't keep up the ride will suffer on rebound and compression.

What is the intended use? Autocross? What tire size are you running?

Just curious.

[bgregg]

What I wanted in a suspension:
Mildly aggressive is OK. I still commute to work in this car every single day, have to navigate multiple speed bumps through my workplace parking lot, have a driveway that has an awkward transition to the street. So not looking for slammed car in any way. Also not looking to be kidney punched by every bump or pothole, on the other hand.

So I am happy with something that handles firmer than stock. I mostly have time for weekend driving some of our great N. California roads, either in the mountains or following the coastline. I attend track days only about 5 times per year, but since I am an experienced track driver I do like the car to be setup so I am not fighting it the whole time.

I had an issue with fitting 235/40-18 front Toyo R888 with -1.8 degrees camber up front as my track configuration. That rubbed the tire on the fender lining after hard driving. Even with rolled fenders. Taking it super easy was OK. 245/40-18 fit the rear OK. So I needed the combination of ride height and more negative camber than just the LCA alone could provide, which led me to either KW Street Comfort coilovers, or this solution. Many coilover kits are for people who want "low as possible" and that is not what I was going for.

This solution will not be used by me for any competition purposes. I don't autocross anymore, and only do the track events for the pure fun of it. I didn't mind being the guinea pig and trying out this Ground Control solution, because I honestly think I can make it work. I think it will solve my negative camber problem, tire clearance and ride height. I should be able to get some good suggestions from the "suspension experts", and adjust.

There are some $119 Bilstein Sport rears and $223 Bilstein Sport fronts, if it takes that to make it "right". Or Koni has some stuff. That might be a conclusion. I think that is the normal recipe for Ground Control to pair up with.

[bgregg]

I guess we have one more question to add to this thread.

4. Will the OEM adaptive dampers work well enough with this kit, for the low cost approach?

If adding new dampers, the total cost of the solution is around $1700 (plus whatever EDC delete costs). Some of the M3 crowd did try out the OEM adaptive dampers. I probably can't do anything very scientific, since I don't own a shock dyno. But I could do GoPro videos of the front tire travel on the road and give my impressions only.

[Pparana]

Really hard to say until you install, will it be optimal no. Will it work enough for you, well that's up to you. If you delete the edc struts, you will have to add a module to avoid the light, that's another 500 or so. Some people say it can be coded off, I remain skeptical.

I am surprised you had rubbing, a little more camber would have solved that. I have run 245 40, on 8.5 inch square setup with the Lcas, et 37 offset. With Dinan springs, I'm about 25" off ground to wheel wheel. No rubbing with fenders rolled, I run 3 degrees all the time, but 2.5 with a better offset would not rub. If your running r888 all the time, your ride tolerance is pretty high. I know your area and yeah you will not want to be too low for driveways hills ext.

[bgregg]

The first test will be with the OEM adaptive dampers, so the question about what it's like in Comfort mode vs. Sport+ mode will be relevant question still.

Yes, the front rubbing will go away with camber plates alone. I have zero issues with the street wheels/tires, it was only the track wheels/tires. I have a good wheel offset +42 and only need to get -2.5 degrees in front to clear. The R888 make plenty of road noise, so I don't drive those around daily, just for track days.

The reason to do more than the bare minimum of just camber plates was the ability to play with ride height. And also to evaluate these Eibach springs.

Actually, I thought the 'original' bare minimum was LCA and lowering springs. Now I have understood why one needs to _also_ do camber plates for large front tires. Anything between original ride height and 0.5" below original ride height works for me. Already have the scrapes on the lower front playing with lower springs and trying my driveway. My friend with the GT3 has the button to press to "raise the nose"!

[Pparana]

well let us know how it works out, esp. If you go to Blistens, that's prob my route when the edc give up. Will prob just buy the module and the shocks, Im good with the ride height on the Dinan and lcas. Figure I have another year at best before there too soft.

[bgregg]

The M3/M4 folks have had a kit available to them that is similar concept, so I mention it here. It seems that KW has made them a Height Adjustable Spring (HAS) system which is also a sleeveover with height adjusters, and retains the OEM adaptive dampers. Their kit does not include the camber plates, however. But the KW kit is not available for other models of BMW. So Ground Control seems to have the opportunity here still.

The reason I mention it, is that the opinion seems to be the the OEM adaptive dampers are well worth keeping and do pair up with a kit. So their design range for compression and rebound and damping seems to work. Well, unless you are hardcore and going racing then you have a different goal for the suspension.

http://f80.bimmerpost.com/forums/sho....php?t=1044712

[Pparana]

Originally Posted by bgregg

The M3/M4 folks have had a kit available to them that is similar concept, so I mention it here. It seems that KW has made them a Height Adjustable Spring (HAS) system which is also a sleeveover with height adjusters, and retains the OEM adaptive dampers. Their kit does not include the camber plates, however. But the KW kit is not available for other models of BMW. So Ground Control seems to have the opportunity here still.

The reason I mention it, is that the opinion seems to be the the OEM adaptive dampers are well worth keeping and do pair up with a kit. So their design range for compression and rebound and damping seems to work. Well, unless you are hardcore and going racing then you have a different goal for the suspension.

http://f80.bimmerpost.com/forums/sho....php?t=1044712

notice they are using a progressive spring in the front, that is really my only gripe about your setup, that and GC components. They are also using a helper spring in the rear, but that my be an m3,4 thing.

[bgregg]

With the suspension loaded up:





Need an alignment again on Saturday:

[Pparana]

Yikes! Did they send you the right spring rate? Also on the rear there is no isolater on the top? Perhaps you were to reuse Oem?

[bgregg]

You probably mean yikes about the front spring remaining travel.

I think the front spring rate does compute to 425 lb/in. From this link:
http://www.ground-control-store.com/...ion.php/II=780

Nowhere near coil bind during street driving. I tried some hard stops, and haven't got to coil bind yet. But I'll get the opinion of Ground Control whether everything looks as expected. It does look like a small amount of front travel.

Rears looks like what I expected for spring travel. I'll ask about the isolators for rear-thanks. Looking at the OEM isolators, they are shaped on the inside with a spring rubber for the OEM spring. The new design has the height adjuster taking the place of this it appears. Also the new design does have a rubber grommet ring for some isolation.

[bgregg]

Ground Control did get back to me and the install is correctly done. Another option for the front is a 5.5" spring at 475 lb/in rating. This would mean giving up 0.5" of lowering potential, and more firm in the front than it already is, but another 0.5" of suspension/spring travel on the other hand.

I am liking the firmness of the 425 lb/in spring, so I don't really want to hurt the street use of the car. I mention it here just to give the information out.

I guess I would be a candidate for a 5.5" spring that is still "street oriented", but there may not be one. Since I am not trying for much lowering and I would end up at the lowest height adjuster threads, and probably end up at stock ride height.

[ocN55]

Originally Posted by Pparana

Really hard to say until you install, will it be optimal no. Will it work enough for you, well that's up to you. If you delete the edc struts, you will have to add a module to avoid the light, that's another 500 or so. Some people say it can be coded off, I remain skeptical.

I am surprised you had rubbing, a little more camber would have solved that. I have run 245 40, on 8.5 inch square setup with the Lcas, et 37 offset. With Dinan springs, I'm about 25" off ground to wheel wheel. No rubbing with fenders rolled, I run 3 degrees all the time, but 2.5 with a better offset would not rub. If your running r888 all the time, your ride tolerance is pretty high. I know your area and yeah you will not want to be too low for driveways hills ext.

Don't mean to derail this thread but I'm in a bit of a time crunch... I would like to run a MPSS 245 up front with a 18x8.5 et38 wheel. Can I run this up front with a minor fender roll (ie no pulling the fenders)? Stock suspension for now btw

[bgregg]

For ocN55, you need camber plates to do what you want. From one of the vendors who makes camber plates compatible with your spring diameter.