Fixed Caster Plates

exdos · 01-23-2013, 07:10 AM

I want to be able to retain the OEM front top mounts of my Z4MC because I want to keep the rubber bushing, but want to increase the caster angle by a fixed amount.

For earlier models of BMW, you can do this with fixed plates, such as those in the photo below. To use these plates, you need to knock out the bolts in the OEM top mounts and fasten the plates to the OEM top mounts by inserting the bolts through the plates and tightening the nut on the underside of the top mount.

I haven't been able to source anything like this for the the Z4MC and so I'm wanting to make a pair of plates myself.

I've already fitted aftermarket suspension on my car, but I can't remember from when I did this job, if I remove the bolts from the OEM top mounts, if there will be any room to fix the nuts on the underside of the top mount, or if the spring perch fits inside the galvanised top mount, as in my photo below.

I would be most grateful if someone could tell me if there's sufficient room for three nuts on the underside of the top mount when the spring perch is assembled, or take a couple of photos showing the layout of the parts. If it's not possible to reattach the bolts, I would leave the existing bolts in place and cut them flush with my caster plates and weld them onto the caster plates and also weld the top mounts to the casterplates around the perimeter of the top mounts.

Thanks to anyone who can help me.

inTgr8r · 01-23-2013, 07:20 AM

great idea!
Ill see if I can get to my old struts (stored) to have a look.

exdos · 01-24-2013, 04:37 AM

Quote:

Originally Posted by inTgr8r

great idea!
Ill see if I can get to my old struts (stored) to have a look.

I'd appreciate that.

The Z3MC has a caster angle of around 9 degrees but the Z4MC it's about 5.5 degrees.

I've made a template to move the top of the strut of the Z4MC by about 20mm, which I reckon should increase the caster by about 2 degrees. If I can bolt my caster plates onto the OEM top mounts, it should be possible to make the caster adjustment variable.

01-23-2013, 07:10 AM	#1
exdos Second Lieutenant 6 Rep 222 Posts Drives: Z3 M Coupe(S54) and Z4 M Coupe Join Date: Apr 2008 Location: UK iTrader: (0)	Fixed Caster Plates I want to be able to retain the OEM front top mounts of my Z4MC because I want to keep the rubber bushing, but want to increase the caster angle by a fixed amount. For earlier models of BMW, you can do this with fixed plates, such as those in the photo below. To use these plates, you need to knock out the bolts in the OEM top mounts and fasten the plates to the OEM top mounts by inserting the bolts through the plates and tightening the nut on the underside of the top mount. I haven't been able to source anything like this for the the Z4MC and so I'm wanting to make a pair of plates myself. I've already fitted aftermarket suspension on my car, but I can't remember from when I did this job, if I remove the bolts from the OEM top mounts, if there will be any room to fix the nuts on the underside of the top mount, or if the spring perch fits inside the galvanised top mount, as in my photo below. I would be most grateful if someone could tell me if there's sufficient room for three nuts on the underside of the top mount when the spring perch is assembled, or take a couple of photos showing the layout of the parts. If it's not possible to reattach the bolts, I would leave the existing bolts in place and cut them flush with my caster plates and weld them onto the caster plates and also weld the top mounts to the casterplates around the perimeter of the top mounts. Thanks to anyone who can help me.
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01-23-2013, 07:20 AM	#2
inTgr8r Lieutenant General 2432 Rep 11,667 Posts Drives: M2 Comp Join Date: Mar 2006 Location: Toronto iTrader: (10)	great idea! Ill see if I can get to my old struts (stored) to have a look. __________________ '21 M2C Hockenheim Silver '18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold)
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