Ground control camber plates install - major questions

[USSEnterprise]

I installed GC camber plates today and the instructions sent with it are very poor. I used Tommy L Garage's youtube video as a guide but he skips over several things in the video as well.

Here are my questions, I would really appreciate thoughts and feedback from guys that have GC camber plates installed. Context: 2018 M3 CS with Eibach V1 Euro lowering springs but stock magnetic/electronic shocks.

1. Instructions say to "reuse stock spring isolator" There is a plastic bearing attached to the bottom of the stock strut top mount (Figure 1), but that would not fit on my new GC top mount. And new GC top mount came with its own bearing anyway. So what is the isolator that is referenced? Just the accordian rubber boot?
2. Can you look at Figure 2 and see if it looks like I installed the strut correctly?
3. Does the black plastic spacer semi-circle (Figure 3) stay in? With it left in, we couldn't pull the wheel out far enough.
4. In Figure 4, after you adjust the camber, how many allen bolts are required to be in to hold the strut in place? For anything more than 4 adjustment markers from the inside of the car to the outside, the two middle allen bolts are taken out of the equation. They just wont thread it as thread moves underneath the plate. That leaves only two allen bolts holding the strut in place. Is that correct??
5. Does the GC camber plates lower the front end?? I swear my front end is now lower as I am scraping on my driveway when I never did prior to GC camber plates.

Thanks in advance, very much appreciated.

[Spun Crankhub]

You my good sir should get your car off the road pretty quick and remedy the fact that the black bearing from your first pic should be on top of the spring. Without that I dont think you have a very good perch to keep that spring from possibly moving around and doing some damage to the underneath portion of the strut tower or on your new camber plates.
I know for fact on the TC Kline camber plates you need to pay for an extra bracket to secure that black bearing to the bottom of their camber plate. Im thinking maybe you need the same from Ground Control, but in your pic I cant tell if there is the ability to snap that bearing into place.
I think that most of the camber plates are made to work with the thin coilover springs, and if you choose to go with stock diameter you need a conversion piece.
Hope this helps

[richf80]

It looks like you're missing a part. See attached picture.

[edit] actually it may be there (spring perch). It's hard to see in the picture.

[USSEnterprise]

Originally Posted by richf80

It looks like you're missing a part. See attached picture.

[edit] actually it may be there (spring perch). It's hard to see in the picture.

Rich you are talking about the metal spring perch correct? Yes, that's installed. I was wondering if there was something required between the metal top spring perch and the spring itself or if its just the accordian dust boot that goes between.

[richf80]

Originally Posted by xxaarraa

Rich you are talking about the metal spring perch correct? Yes, that's installed. I was wondering if there was something required between the metal top spring perch and the spring itself or if its just the accordian dust boot that goes between.

Yea you are right. The dust boot is the only thing I had installed between the spring perch and spring.

Also the camber plate is supposed to be pushed towards the engine for more negative camber. Looks like the opposite direction in your picture. I don't have these installed anymore, but I took a picture next to my vorshlag plates and drew an arrow in the direction the need to be pushed for reference.

[USSEnterprise]

Originally Posted by richf80

Yea you are right. The dust boot is the only thing I had installed between the spring perch and spring.

Also the camber plate is supposed to be pushed towards the engine for more negative camber. Looks like the opposite direction in your picture. I don't have these installed anymore, but I took a picture next to my vorshlag plates and drew an arrow in the direction the need to be pushed for reference.

Yes, towards the motor is right. The pics were to show that plastic spacer and the fact that only two allen bolts line up to holes. I haven't tightened it down yet.

Folks that have -2.5ish front (CanAutM3?), can you post a pic of your camber plates? I want to see what marker on the plate you are set to.

[dvq]

Originally Posted by xxaarraa

Yes, towards the motor is right. The pics were to show that plastic spacer and the fact that only two allen bolts line up to holes. I haven't tightened it down yet.

Folks that have -2.5ish front (CanAutM3?), can you post a pic of your camber plates? I want to see what marker on the plate you are set to.

If you're trying to see what settings to use to preset yours at -2.5 that won't work, ride height affects camber.

If you're trying to solve your bolt hole configuration issue the following threads will help.

https://f80.bimmerpost.com/forums/sh...8;postcount=15

https://f80.bimmerpost.com/forums/sh....php?t=1289488

[IVM3]

One other tip is to make sure you have the bumpstop oriented the right way. The flat end (not cone shaped) goes towards the top. I ended up installing mine upside down and had to redo it.

With the allen bolts in the original configuration, you'll end up around -2.5 camber when getting to max setting on stock suspension. You'll have to move those bolts to the race position to go more negative. I put mine in the race configuration near the minimum camber it will allow to be slightly more than -2.5. In either configuration, you need to have a total of 4 allen bolts on each side.

[USSEnterprise]

Thanks a lot for all your thoughts so far. Your answers clears up my questions around adjustment positions of allen bolts on the camber plate and also installation in general.

UPDATE: I had a lengthy conversation with James at Ground Control and we have determined that my install is correct and my loss of ride height is due to the bump stops. i.e., The bump stops (wrong term for them, as they are called "supplemental springs" by BMW according to GC) that shipped with GC kit are much smaller than the OE bump stops I was using. Incidentally, GC supposedly ships the same bump stops that Dinan sends with their ride quality kit for lowered cars.

If I wanted to go back to my old ride height (which I do), James advised cutting off the top portion of the GC bump stops and stacking that on top of my OE bump stops. He says I cannot just reuse my OE bump stops as is, because the large diameter of the tops of them (flat end not conical end - see pic below) supposedly will bind the GC strut bearing on turning/compression.

Anyone know why I cannot just flip the OE bump stop upside down and put the smaller diameter conical end up top? I know they are progressive and not all parts of the bump stop compress at the same rate, however, flipping a 'spring' upside down should not affect the progressive nature of it?? Anyone with experience flipping bump stops upside down? - @IVM3, why did you not leave it flipped??

[IVM3]

I believe the diameter of the stock bumpstop is still too big if installed upside down. It will hit the GC bearing instead of resting inside the fixed part of the camber plate. When I had the ground control bump stop installed upside down, I realized that it will hit the bearing part that is supposed to spin freely because of the diameter of the conical portion. It's not supposed to hit that or it will bind. It's easy to tell once you have it apart and test fit the bump stop against the bottom of the camber plate.

The bigger issue is that if your car sits lower using the ground control bump stops, then that means that your car must be literally sitting on the stock bump stops at rest. I'm surprised to hear that your ride quality is still okay if it's resting on the bump stops.

[USSEnterprise]

Originally Posted by IVM3

I believe the diameter of the stock bumpstop is still too big if installed upside down. It will hit the GC bearing instead of resting inside the fixed part of the camber plate. When I had the ground control bump stop installed upside down, I realized that it will hit the bearing part that is supposed to spin freely because of the diameter of the conical portion. It's not supposed to hit that or it will bind. It's easy to tell once you have it apart and test fit the bump stop against the bottom of the camber plate.

The bigger issue is that if your car sits lower using the ground control bump stops, then that means that your car must be literally sitting on the stock bump stops at rest. I'm surprised to hear that your ride quality is still okay if it's resting on the bump stops.

Yes, you are correct. Here's a photo of my stock bumpstop (used in conjunction with the Eibach lowering springs) and you can see that car 'rides' the bump stops just a hair - the darkening at the bottom of the stops supposedly indicates that, per GC.

1. I can tell you ride quality on the road in comfort mode is pretty good. In fact, even my wife commented how the CS seems to ride smoother than my Lotus Evora which in itself is a very nice ride for a sporty car.
2. And when in sport + on track, I imagine the dampers are firmed up to the point that it doesn't ride on the bump stops. I am about 5-6 trackdays in and have no complaints to report - I go over curbs at apex pretty aggressively and have not noticed any rubbing or bodyroll or weight transfer impediment.

You put 1 and 2 together, and I don't really care if car rides the bump stops to be honest. With the shorter GC bump stops, my front lip is barely 4 inches off the ground and it quickly becomes stressful to drive a car that scrapes everything. I plan to take it apart and will an update and pics of both stock and GC bumpstops side by side.

Is the bump stops being an integral part of the suspension a BMW thing? In all the cars I have owned, I have never had to think so deliberately about bump stops.

[USSEnterprise]

OK I got this done. Posting an update for anyone coming across this thread in the future.

James at GC had suggested cutting off a portion of the GC bumpstop and stacking that on top of my whole OE bumpstop. Upon looking at it closely, I decided to do the opposite - use the whole GC bumpstop and add a piece cut off from my stock bumpstop instead.

I made this decision because the GC bumpstop is designed to fit their strut top and bearing perfectly, just like the stock bumpstop is designed to fit the stock strut bearing like a glove. I'm sure you guys are all saying "no shit" but I have never encountered bump stops being such an integral part of the suspension (new to BMWs) till now so this was a big "ah hah" learning moment for me: Specific bump stops are designed to be paired with specific strut top / bearing being used. That way they fit within the strut top and will not bind the rotating bearing. See pic below to see how GC bump stop fits with GC strut top perfectly.



This is what I ended up doing - cut off the first layer of my OE bumpstop and stacked it beneath the GC bumpstop.



This is what I gained back in ride height (about a third of an inch):

At the fender:


At the front lip:


I have verified it doesn't scrape my driveway anymore. And car is going in tomorrow for RE-71Rs which are about half inch taller in diameter (265x35 versus 255x35) so adding that quarter inch I will gain from the tires, my ground clearance issues in everyday life should become a non-issue.

One last note: I am not going to claim this doesn't negatively impact my ride quality. I do realize I am in fact using foam bump stops to raise ride height. Two reasons I am comfortable doing this:

1. When we start tinkering with a factory setup by lowering (Eibach springs) and changing strut tops (GC camber plates) etc. every decision that follows is a series of cascading trade-offs. Not sacrificing ride height in favor of a marginal decrease in ride quality is the trade-off I am comfortable making. Especially since I believe that when dampers are in sport + mode at the track (75% of my seat time with this car), I don't think the bumpstops come into play at all so this tradeoff is only when in everyday road use in comfort mode (driving to and from track). YMMV obviously.
2. I am never going to keep the car long enough for the bump stops to wear out and become a maintenance issue. I am at 6k miles, and car will be long gone by the time I get to 10-12k miles. 15k at the most. Of course I meticulously maintain my track vehicles so I will keep an eye on it, but not worried about them lasting any meaningful length of time.

I'll post an update in the future after I've got it aligned and run a few track days with any observations regarding ride quality, performance etc.

Thanks to everyone that contributed to this thread to help me figure this out. I appreciate having you guys.

[USSEnterprise]

Got the alignment done today after the camber plates, everything good so far. Also posting a photo of where my plates are set - I know this will be different for different cars, but posting anyway.

[IVM3]

Glad you got it all sorted out and thanks for sharing the various pictures. Your picture of how the bumpstop fits would have saved me from the mistake of installing mine upside down.

[hC1001]

Why the big discrepancy from side to side? Are both sides around the same ride height or did you raise the driverside a little higher?

Im at -2.4 and around the middle of the same mark as your driverside.

[dannyz_M4]

Im installing the GC plates currently, on stock struts, but lowered mss springs.. wondering if i use the original perch bearing on figure 1, or not???

Thanks

[IVM3]

Originally Posted by dannyz_M4

Im installing the GC plates currently, on stock struts, but lowered mss springs.. wondering if i use the original perch bearing on figure 1, or not???

Thanks

You don't reuse the stock perch bearing on any GC camber plate setups. The piece you should reuse, if it's still there, is the rubber spring isolator boot. It helps to keep things quieter by not having metal on metal contact between the top of the spring and the bottom of the camber plate.

[dannyz_M4]

Originally Posted by IVM3

You don't reuse the stock perch bearing on any GC camber plate setups. The piece you should reuse, if it's still there, is the rubber spring isolator boot. It helps to keep things quieter by not having metal on metal contact between the top of the spring and the bottom of the camber plate.

Oh that's great!! Thanks!! I was confused when the website says "reuse spring isolator" wasn't sure what they meant with that.

Install went well, reused the dust-boot/isolator. The supplied perches on the GC plates. And dialed in a lot of neg camber.

Only headache I DID have was that they must have installed the brace top part of it ( the chrome part that attaches to the alloy oem brace) in reverse with the drivers side and passenger side. All was going well until I was re installing the alloy brace and it was no way near even lining up.. was scratching my head for ages, thinking I may have to drill out holes in my brace... But, took the plates out and re checked and realized they must have from factory put them on the wrong sides. Ended up just taking those 6 tiny Allen bolts out and swapping them to the other side..

Otherwise just scratching my head and a bit of a time waster..

Very happy with the plates. No noise or clunking and front end feeling is great!!

[rborane]

What is the black plastic semi circle shown in figure 3 for? Is that meant to stay on the plates?

[IVM3]

Originally Posted by rborane

What is the black plastic semi circle shown in figure 3 for? Is that meant to stay on the plates?

That's a spacer that you put under the metal adjusting plate when you use the camber plates in the race position to get more than -2.5 camber. I think the instructions that came in the box describe it. It just sits right under the silver plate and the 2 of the 4 hex screws go through it.