Audi R8 clutch

Hi. I am building a custom car with a 2014 Audi R8 Graziano transaxle. I have to build a custom flywheel as I am using a MB B12. I have the stock v10 clutch. The stock Audi flywheel has a recess the clutch plates sit in. This recess is below the pressure plate mounting surface. Can anyone help with the recess dimension? Thanks in advance. Mike