help with Ground Control camber plates

#21

I dunno man. I thought I had it with the upside down idea.

Look at these pics. Are yours the same? http://forums.bimmerforums.com/forum/showthread.php?t=1707296

This is an easy issue, we’re just missing something obvious.

#22

yeah those plates are the same as mine. I think it might just be an issue with the close fit and setting it up with as much negative camber as possible. It doesn’t look like they will be on in time for VIR next weekend. Maybe for road atlanta the first weekend in august. Despite this being such a pain, i’m learning a lot about the suspension.

#23

I saw that other thread. You confused them so there answer doesn’t make sense in this context.

Grab one of your struts and put the spring hat on it, then put the camber plate on top of that. Take lots of pics. Specifically take pics to ID what is an is not creating enough clearance between camber plate and spring hat, and what is preventing the strut rod from going deeper into the camber plate. Don’t just take random pics, the pic has to clearly show why things are happening or not happening. Photoshop arrows on to the pics if you have to. We’re spending too much time jawwing and not enough time looking.

Re. feeling like you’re getting no where. This is nothing. We’re figuring out a problem that is easy. Just you wait until big problems occur that don’t make any sense at all. Be strong.

#24

I actually talked to the guy at ground control that designed the plates and he said i have everything that is correct. I just need to get the camber set at -3.5 and they will not bind. He said it will be close but there is enough room. I’ll see if the shop can re install and go from there. I’ll keep you posted.

#25

Dude, there is confusion here. “I just need to get the camber set at -3.5 and they will not bind.” is flat-ass wrong. Don’t go making yourself crazy chasing phantoms.

The camber plates should be perfectly happy between about -2.6 to -3.3 or so. They will get less happy at more than about -3.3, and the exact number will vary from one car to the next, because the spring hat will bind on the inside of shock tower. Nothing you do with the camber plate is going to change that so you can screw with it, bang on it, and sing to it, but nothing is going to change the fact that the spring hat is going to bind on the shock tower as you approach -3.5

There is communication confusion between you and this other guy. You say that your spring hats are binding when they shouldn’t, and you say that there isn’t enough rod from the strut poking thru the camber plate. Moving your strut/spring/hat inboard towards -3.5 isn’t going to help any of that.

#26

I did get a little confused at first as to what the shop was telling me. At first i thought the main issue was the rod on the end of the shock being to short for the bolt to thread on to. After talking to them a little more about the problem i understood that the rod had just enough to get the bolt tight, but the bottom of the plates were binding with the top of the hat. The shop wasn’t sure this was correct and pulled the plates back off. We were not sure what setting they originally installed the plates so sometime today or next week they are going to re install them and play with the settings accordingly to see what will and will not bind. After a lot of reading from various sites and emails from ground control i believe what i have is correct. It’s just a really tight fit. I don’t want to set the camber at -3.5 and leave it at that because then what would the point of having adjustable camber plates be? I would ideally like to be able to adjust between -2.5 to -3.5.

#27

The problem seems to be the spring hat binding with the top of the shocktower. This focus on -3.5 as the solution is misguided because as you slide the camber plate inboard to gain more camber, the spring hat binds in the inboard side of the shocktower.

Said a different way, you are describing a problem with binding on the top, yet talking about a fix that involves binding on the side.

Lets talk some basics here of how the camber plate, shock tower and spring hat interact.

Stack height and spring hat binding. A camber plate that is designed to work with the OEM spring hat has a cylinder underneath it’s thrust bearing. It’s about an inch in dia and an inch tall. The shock’s rod comes up thru that cylinder and therefore thru the thrust bearing. The purpose of that cylinder is to provide “stack height”, which is to say, it shoves the spring hat down far enough that the spring hat’s upper surface doesn’t bind with the shock tower’s lower surface. That’s the binding that you are describing.

Camber and spring hat binding. The spring hat is about 6" in dia. and the top of the shock tower isn’t much more. The shock’s rod comes up thru the camber plate and the camber plate allows the shock rod to be slid inboard and outboard. When you attempt to gain camber you shove the shock rod’s slider plate, and therefore the spring hat underneath, inboard. But you can’t shove the slider plate very far because the spring hat, under the shock tower, is almost the same dia. and the shock tower so there’s just not much available travel for the spring hat. Once you shove the slider and spring hat 15mm inboard or so the spring hat will bind on the inboard side of the shock tower. This will be especially apparent when you turn the steering wheel because the rotating spring hat will grind into the inboard side of the shock tower, or if the wheels are off the ground the spring hat may pop off it’s correct orientation with the spring.

What really limits your camber adjustment is not the design of the camber plate, but the inescable geometry of the spring hat and shock tower.

Bottom line last. What you are describing is stack height binding and the solution the shop seems to be embarking on is camber binding. The part that is especially confused is the idea that “if we can get -3.5deg, the stack height binding will go away”. That’s like saying “if we can just get the side of the spring plate to bind, then the top won’t bind”.

#28

Ranger is right, so is your shop. The GC plates (which I just installed last week) in trying to get mad low stack height yo, do scrape/bind. The spring perch grinds against the bottom side of the outside stud that is welded to the plate. My friend also had this same issue on his car. Our solution was to reinstall the stock washer that goes underneath the stock shock mount. The washer is thin enough to allow full engagement of the bilstein locknut. My late model is no where near 3.5* camber in the front with the plates moved in as far as they can go without binding, my friends car can easily achieve 3.5*… big variations in chassis over the years.

#29

Ranger,

sorry for the long delay in response. The shop was successfull with putting on the camber plates. We used new bilstein shocks and they installed perfectly. The top of the shocks did have a different end compared to the older shocks that were already on the car. I haven’t been over to see them yet. Also won’t be able to make RA due to a highway accident headed to VIR. Good luck.

Craig