I am making my own hub centric spacers for my C6 front brake upgrade. My street wheels are torq thrust Ms which have very little caliper clearance so I will need to move the wheel out a bit. I already have longer racing studs, but my question is:

How thin can I safely make it? I need about 1/2" or 13mm and I was planning on having a 9mm recess for the wheel bearing hub to go into and then a 9mm hub for the wheel to go over. Is the remaining 4mm overlap good enough? Would anyone be willing to measure some that they have for me?

 

Anyone?

 

I have 16mm hub-centric spacers that I had machined to be hub-centric and lug-centric, the spacer is a better fit to the hub than a wheel and the spacer is a much better (snug) fit to the bore of the wheel. The wheel studs are very snug. I had sufficient material to be very comfortable with the back-side bore of the spacer.

Mine were done for the rear of my ZR-1 to run 50mm offset 11" wheels. My back-side depth was calculated by using the hub center depth less the thickness of the rotor plus 1mm for a cushion. I don't have similar parts to yours to calculate what would be required for a back-side bore BUT you could do this to GAIN on the situation! You could have the hub center machined to a height less than what you've got now to fit the spacer!

These numbers are what come to mind for the rear hub center and rotor thickness for the rear of my ZR-1. Hub height 19-20mm and the "rotor-hat" thickness 9-10mm (greater than 9 I recall but not 10). With a 16mm spacer I had a "cushion" of 5mm+! If the C6 rotor has a thicker "hat" you've gained some already, if it's the same as a C4 rear you need to only have the hub machined to compensate.

In the "hills of WV" some might just take a "grinder" to the hub-center to loose the required height! The height of the hub-center serves "no purpose" beyond what is require to fit the spacer "back-side" bore!

If you need a 13mm spacer I'd say an 8mm back-side bore depth would give you a 5mm "cushion"! I'd say that is "sufficient"!

Another thing you need to check is the "hub bore" of your wheels! You want the spacer to "match" the wheel not just to duplicate the hub-center diameter of the hub!! This gives you the "fit" you want/need. Mine I believe were + 2mm!

 

Thanks! This is what I was thinking but I wanted to confirm.