There are a handful of options out there for strut mounts/camber plates, but not a whole lot of information on the details and differences. I’m mostly concerned with streetable, quiet options with some sort of isolation. I wanted to see the differences up close and figured I would share the info. Hopefully this makes sense.
In regards to ride height and suspension travel, these are the two main measurements I took: top of mount to thrust bearing seating surface and top of mount to strut shaft seating surface. Examples:
OE BMW Strut Mounts
Top of mount to thrust bearing seating surface: 36.25mm
Top of mount to strut shaft seating surface: 80.5mm
Difference: 44.25mm
Mounting stud length: 18.5mm
Top plate surface diameter: 145mm
Weight: 1.72lb
Ground Control Street
Top of mount to thrust bearing seating surface: 38.75mm
Top of mount to strut shaft seating surface: 68.75mm
Difference: 30mm
Additional bump travel compared to OE Strut Mount: 14.25mm
Change in ride height compared to OE Strut Mount: +2.5mm
Top of mount to GC 60mm spring perch (if used): 55mm
Mounting stud length: 16mm
Top plate surface diameter 120mm
Weight: 2.49lb
The Ground Control Street plates use an OE type thrust bearing to support the weight of the car, and a large urethane bushing to locate the strut shaft. The thrust bearing and shaft bushing are mounted at a slight angle, which GC says is similar to the OE strut mounts. The idea is that this will reduce side loads and binding. I should note that the GC mounts came with a wrap of electrical tape where the thrust bearing sits, apparently to take up some lateral play. The GC plates don’t have a lot of caster adjustment; the caster adjustment is made up of “slop” in the camber adjustment slots ( ~1/8”). Probably not a big deal… How much caster adjustment do you need? The GC plates have about an inch of camber adjustment.
Turner Street
Top of mount to thrust bearing seating surface: 31.25mm
Top of mount to strut shaft seating surface (including 7mm shock spacer): 70mm
Difference: 38.75
Additional bump travel compared to OE Strut Mount: 5.5mm
Change in ride height compared to OE Strut Mount: -5mm
Top of mount to Turner 60mm spring perch (if used): 50.5mm
Mounting stud length: 26mm
Top plate surface diameter: 127mm
Weight: 2.21lb
Shock spacer thickness: 7mm
The Turner Street plates use an OE type thrust bearing to support the weight of the car, and a smaller (purpose-made?) urethane bushing to locate the strut shaft. The Turner website mentions that the Street plates incorporate the same mount angle as the OE strut mounts, but everything sure looks square to me. Turner supplies a 7mm “shock spacer” that is supposed to go on the shaft between the mount and the stock strut washer. See E46_M3_Camber_Plate_street.pdf The purpose of the spacer is to prevent the stock large strut spacer disk from contacting the camber plate body itself. If the large strut spacer disk isn’t used (i.e., with coilovers), I think the Turner shock spacer could go on top of the plate to gain 7mm of bump travel. With coilovers, you could also raise the car to make up for the 5mm ride height lost with these plates. In total, that could give you an additional 16mm or so additional bump travel compared to stock strut mounts. The Turner street plates have about 0.5” of caster adjustment and just shy of an inch of camber adjustment.
Turner Hybrid
Top of mount to thrust bearing seating surface: 35.75mm
Top of mount to strut shaft seating surface (including bushing as shown in instructions): 55.3mm
Difference: 19.5mm
Additional bump travel compared to OE Strut Mount: 24.75mm
Change in ride height compared to OE Strut Mount: -0.5mm
Top of mount to Turner 60mm Spring perch (if used): 54.5mm
Mounting stud length: 22mm
Top plate surface diameter: 122mm
Weight: 2.67lb
Shaft bushing 1 stack height: 9.4mm (installed on bottom for measurements above)
Shaft bushing 2 stack height: 11mm
The Turner Hybrid plates use an OE type thrust bearing to support the weight of the car, and a spherical bearing surrounded by urethane to mount the strut shaft. The spherical bearing allows the angle of the shaft to change freely as the suspension moves up and down, but the urethane provides some isolation of NVH. The thrust bearing is mounted parallel to the plate. The hybrid plates came with a package of hardware (bushings, spacers, rubber “seals” and adapters) and instructions for the street plates that aren’t really applicable to the hybrid plates. After playing around with the parts, I think I was able to figure out how the parts in this package are intended to fit together. The spherical bearing is not sealed, so Turner includes rubber seals to go on the top and bottom of the plate. The bottom seal uses the included large strut spacer disk to center it on the strut shaft (the stock spacer disk would not do this), and the top seal uses an included spacer ring to center it. I don’t love the way the seals fit (especially the top one), but better than nothing I suppose. The inner diameter of the spherical bearing is more than 16mm, so Turner includes bushings to fit OE shaft diameters. For some reason there are two different bushings (two pairs of top and two pairs of bottom), and one has a taller stack height than the other. I thought installing the taller bushing on the bottom of the bearing provides more clearance for articulation, so my pictures were taken like that. I later found that Turner provides installation instructions for the E9x Hybrid plates: PDF_3407_BMW_E9x_M3_Turner_Hybrid_Front_Adjustable _Camber_Plates.pdf The E46 M3 install should be essentially identical. In the diagrams, it looks like the shorter bushing is intended to go on the bottom.
My car is primarily a street car, so NVH, suspension travel and longevity are primary concerns to me. I run a stock-ish alignment these days and the car isn’t very low, so the OE strut mounts would be my first choice if bump travel isn’t a concern. I’m going to try the Bilstein B12 kit and will be using the Turner Hybrid plates to gain almost an inch of bump travel compared to using the stock strut mounts.
In regards to ride height and suspension travel, these are the two main measurements I took: top of mount to thrust bearing seating surface and top of mount to strut shaft seating surface. Examples:
OE BMW Strut Mounts
Top of mount to thrust bearing seating surface: 36.25mm
Top of mount to strut shaft seating surface: 80.5mm
Difference: 44.25mm
Mounting stud length: 18.5mm
Top plate surface diameter: 145mm
Weight: 1.72lb
Ground Control Street
Top of mount to thrust bearing seating surface: 38.75mm
Top of mount to strut shaft seating surface: 68.75mm
Difference: 30mm
Additional bump travel compared to OE Strut Mount: 14.25mm
Change in ride height compared to OE Strut Mount: +2.5mm
Top of mount to GC 60mm spring perch (if used): 55mm
Mounting stud length: 16mm
Top plate surface diameter 120mm
Weight: 2.49lb
The Ground Control Street plates use an OE type thrust bearing to support the weight of the car, and a large urethane bushing to locate the strut shaft. The thrust bearing and shaft bushing are mounted at a slight angle, which GC says is similar to the OE strut mounts. The idea is that this will reduce side loads and binding. I should note that the GC mounts came with a wrap of electrical tape where the thrust bearing sits, apparently to take up some lateral play. The GC plates don’t have a lot of caster adjustment; the caster adjustment is made up of “slop” in the camber adjustment slots ( ~1/8”). Probably not a big deal… How much caster adjustment do you need? The GC plates have about an inch of camber adjustment.
Turner Street
Top of mount to thrust bearing seating surface: 31.25mm
Top of mount to strut shaft seating surface (including 7mm shock spacer): 70mm
Difference: 38.75
Additional bump travel compared to OE Strut Mount: 5.5mm
Change in ride height compared to OE Strut Mount: -5mm
Top of mount to Turner 60mm spring perch (if used): 50.5mm
Mounting stud length: 26mm
Top plate surface diameter: 127mm
Weight: 2.21lb
Shock spacer thickness: 7mm
The Turner Street plates use an OE type thrust bearing to support the weight of the car, and a smaller (purpose-made?) urethane bushing to locate the strut shaft. The Turner website mentions that the Street plates incorporate the same mount angle as the OE strut mounts, but everything sure looks square to me. Turner supplies a 7mm “shock spacer” that is supposed to go on the shaft between the mount and the stock strut washer. See E46_M3_Camber_Plate_street.pdf The purpose of the spacer is to prevent the stock large strut spacer disk from contacting the camber plate body itself. If the large strut spacer disk isn’t used (i.e., with coilovers), I think the Turner shock spacer could go on top of the plate to gain 7mm of bump travel. With coilovers, you could also raise the car to make up for the 5mm ride height lost with these plates. In total, that could give you an additional 16mm or so additional bump travel compared to stock strut mounts. The Turner street plates have about 0.5” of caster adjustment and just shy of an inch of camber adjustment.
Turner Hybrid
Top of mount to thrust bearing seating surface: 35.75mm
Top of mount to strut shaft seating surface (including bushing as shown in instructions): 55.3mm
Difference: 19.5mm
Additional bump travel compared to OE Strut Mount: 24.75mm
Change in ride height compared to OE Strut Mount: -0.5mm
Top of mount to Turner 60mm Spring perch (if used): 54.5mm
Mounting stud length: 22mm
Top plate surface diameter: 122mm
Weight: 2.67lb
Shaft bushing 1 stack height: 9.4mm (installed on bottom for measurements above)
Shaft bushing 2 stack height: 11mm
The Turner Hybrid plates use an OE type thrust bearing to support the weight of the car, and a spherical bearing surrounded by urethane to mount the strut shaft. The spherical bearing allows the angle of the shaft to change freely as the suspension moves up and down, but the urethane provides some isolation of NVH. The thrust bearing is mounted parallel to the plate. The hybrid plates came with a package of hardware (bushings, spacers, rubber “seals” and adapters) and instructions for the street plates that aren’t really applicable to the hybrid plates. After playing around with the parts, I think I was able to figure out how the parts in this package are intended to fit together. The spherical bearing is not sealed, so Turner includes rubber seals to go on the top and bottom of the plate. The bottom seal uses the included large strut spacer disk to center it on the strut shaft (the stock spacer disk would not do this), and the top seal uses an included spacer ring to center it. I don’t love the way the seals fit (especially the top one), but better than nothing I suppose. The inner diameter of the spherical bearing is more than 16mm, so Turner includes bushings to fit OE shaft diameters. For some reason there are two different bushings (two pairs of top and two pairs of bottom), and one has a taller stack height than the other. I thought installing the taller bushing on the bottom of the bearing provides more clearance for articulation, so my pictures were taken like that. I later found that Turner provides installation instructions for the E9x Hybrid plates: PDF_3407_BMW_E9x_M3_Turner_Hybrid_Front_Adjustable _Camber_Plates.pdf The E46 M3 install should be essentially identical. In the diagrams, it looks like the shorter bushing is intended to go on the bottom.
My car is primarily a street car, so NVH, suspension travel and longevity are primary concerns to me. I run a stock-ish alignment these days and the car isn’t very low, so the OE strut mounts would be my first choice if bump travel isn’t a concern. I’m going to try the Bilstein B12 kit and will be using the Turner Hybrid plates to gain almost an inch of bump travel compared to using the stock strut mounts.
Attached Files
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