Hey IsItElectric?...my GC plates

[Hellabad]

Dang. Now I wish I had left the other pict up. I could have sworn the style bolts were the same on both sides. Maybe you have a pict?

Just call ok. A lot of the pictures on our website are going to vary because everything we do is custom. If it needs a washer we use a washer, if it doesnt need one, we may or may not include one. Sometimes we use a washer just as a .060 spacer for thread engagement, which may not be apparent.

If you need to send pics, send them to Mark, he or I can explain whatever question you may have.

Jay from GC

[IsItElectric?]

My name is Jay from Ground Control. The number one reason for plates "bending or buckling" is bottomed out Bilsteins. I am guessing you have Bilsteins, and probably your sheetmetal is bent to.

Those plates are 7075 T6, but GC also has 4130 steel rally plates. All of our stuff is guaranteed, but there is a little bit of responsibility (for everyone) to be sure your car isnt beating the hell out of the strut towers.

Call and ask for Mark about warranty, but I am concerned that even with the steel plates, you will just be bending your strut towers until you fix whatever is causing the problem in the first place.

Also check for coilbind, but I really think you are riding on the bumpstops, its pretty common.

Jay from GC

Jay,

Sorry, but that's not the right diagnosis. I have the full GC kit, with the specific GC part number SA Konis, the Eibach springs from your kit, my housings are shortened by 1" and re-welded, etc etc. I even took all the dimensions myself and measured what the stack height of the spring would be even if I bottomed it out to ensure there would still be strut travel left. I did this for both the top and bottom of my height adjustment, to ensure I would be ok no matter what. I have been about 1.125" off the 'bottom' of the spring perch with the ride height adjuster.

Edit: by 'measuring', I mean that I measured to ensure I would always hit the bump stop first before packing the spring...sorry if my wording was unclear

All my components were purchased new this year from one of your reputable distributors.

To this point, I haven't changed anything at the upper end, and the aluminum is buckling. I also have a steel strut tower brace which probably helps to distribute load. My strut towers are fine....I have checked.

0.090" is just too thin. However, mine are even buckling on the part that uses the ENTIRE thickness of the upper plate as a bearing surface. Furthermore, they are buckling downward, not upward. Maybe we can discuss this issue in greater detail over the phone? I'm in no way trying to bash GC, however, I want a resolution. I am an mechanical design engineer and am a bit dissatisfied at this point considering I can see how it is failing.

Currently, I'm leading the Philly SCCA Region in Street Modified after 6 events, and I would like to continue doing so.

Thanks!

-John

[SkinnyVT]

can you post pics of the plates? It would be nice to see what is actually happening.

[Quailane]

Wow, I was just about to buy E30 GC camber plates but now I'm not so sure on what to do.

[DRTSRFR]

I'd like to see pics too. I have two sets of these plates and haven't had any problems.

[bmwpower]

Just call ok. A lot of the pictures on our website are going to vary because everything we do is custom. If it needs a washer we use a washer, if it doesnt need one, we may or may not include one. Sometimes we use a washer just as a .060 spacer for thread engagement, which may not be apparent.

If you need to send pics, send them to Mark, he or I can explain whatever question you may have.

Jay from GC

I just rechecked my SpecE30 plate. You're right - there is no room for a washer. Bummer.

[IsItElectric?]

Hey everyone,

First, let me clarify a bit. I'm not trying to throw GC under the bus for what we're discussing here. They make a nice system with some cool features. They even have their own unique part number from Koni for the struts. It's a great setup. I am a lot faster this season compared to last season, and the GC setup is a big reason.

Now onto the nitty gritty.

I drive my car to every event, and adjust the camber accordingly so I don't chew up tires. Therefore, I need it to bolt / unbolt easily and quickly. I found the head of the button head screw (where you insert the allen wrench) would quickly strip with all the tightening / loosening. So I wanted to get a bolt that could accept a larger allen wrench, so I spec'd out some socket head cap screws and washers. I took the dimensions carefully of the button heads to AT LEAST mimic the OD of the button head, to distribute the force with the SHCS & washer. This is because the SHCS head of the same thread size & pitch is much thinner, and would have a much higher point load on the top plate when torqued down.

Also to note, I did use washers on the recessesd slot. I simply ground down the outer portions of the washer to make them a bit more oval so they would fit into the slot. When I was done, they would just barely fit into the slot.

The four bolts that unite the top plate to the spherical bearing housing don't need much torque to operate properly....somewhere in the neighborhood of 15-20 ft-lbs at most. When adjusting at autocrosses, I did not use a torque wrench, however I am pretty careful. Perhaps, however, there was too much torque applied, given the pictures.

Now, these plates have seen 6 events this season...maybe 7. I believe that perhaps I did use too much torque...that certainly is possible.

However, I also believe that perhaps the top plates would have done the same thing given more time, even with repeatedly using the correct torque. I believe the top plate should be a bit stronger to aid in preventing this from happening. In any case, I'd like to try the GC steel plates to see if it makes a difference. Plus, it does appear GC has already taken steps to change their design as seen by bmwpower's post regarding the thickness of his plates relative to mine. That plate shown previously in this thread is much thicker than mine.

In any case, I am trying to work with GC to a resolution....whether I over-tightened them or perhaps I should try the steel plates. But for anyone considering buying one of their systems, I wouldn't hold back b/c of this!

[DRTSRFR]

Holy torque wrench...that can't be 20 pounds of torque???

I checked mine last night and they barely made an impression on my plates.

[bmwpower]

I dont know others but i didnt receive any instructions with my plates. So i would be in the same boat without torque specs.

[SkinnyVT]

I think it is pretty obvious that the combination of a bolt with a smaller head and more than likely too much torque caused the damage. Too much torque would also explain why you were stripping the button heads.

[IsItElectric?]

I think it is pretty obvious that the combination of a bolt with a smaller head and more than likely too much torque caused the damage. Too much torque would also explain why you were stripping the button heads.

Yeah, you're probably right, especially considering the wimpy washers I used with the SHCS which did in fact apply a higher point load to the edges.

For the next go-around, I am going to use hardened 5/16 washers on the front side of the plate (part without the recess) and continue to use SHCS which I like better because they're easier to grab with a tool. On the recessed side, I'll probably go back to button heads because even as I modeled it in 3D, there's not a better choice of hardware really.

Oh, and using a smaller wrench to tighten and / or a torque wrench may help too!!! :)

[SkinnyVT]

and make sure your allen key is in good condition

[rwh11385]

Maybe use GC-supplied hardware and torque properly next time? Just a thought.

[bmwpower]

Maybe use GC-supplied hardware and torque properly next time? Just a thought.

So what is the recommended torque?

[IsItElectric?]

So what is the recommended torque?

Per the Bentley manual, the recommended torque for the nuts to unite the strut tower to the bearing-plate are 16 ft-lbs. Being that the GC bolts are of similar size, I would use that as a guide.