Yes, 10mm. DIY with your local machine shop or http://www.agency-power.com/catalog/...6dccqtrv1chl27

 

The exact thickness of the spacer needs to be .440" or 11.18mm to get the perfect spacing.

 

As far as rear is concerned 11mm rear spacers seem to work well, made up by local machine shop, using stock rear calipers with longer bolts and 997 turbo rear discs. I have drawings for these spacers if anyone is interested.

 

What does your pad look like against the rotor near the OD?

 

Not sure you can see on this pic, but pad follows contour of disc as per stock setup

 

Hmm, hard to see there. Here's what I'm wondering about: you never want the friction material to go off the rotor - you always need to have a 'cold ring' around the rotor OD which the pad doesn't touch. Because you spaced things off further than usual, you should double check that.

 

The 11mm spacer is perfect. I had my spacer at 11.18mm (.440") and the fit was perfect and no issues running on a track car. The friction material does not go off the rotor. What purpose would that serve? No need to over analyze this.

 

I'm wondering that too, what is the purpose of the "cold ring"

 

As above...the whole idea of fitting spacers/larger discs is to maximize leverage.

 

There's no performance purpose - it's just for safety. Pads can 'chunk out' or fragment if they get clamped on an uneven surface - i.e. if they see large variations in surface pressure. So engineers analyze the positional tolerances of all the parts to make sure the pad will never sit off the OD of the rotor. When I worked on OEM brake systems, this was just one of the many boxes that needed to be checked.