Does anyone know the oem rocker arm ratio on a 2006 r53?

 

Intake: 1.65:1
Exhaust: 1.43:1

 

Awesome thanks..how about stock cam lift?

 

I believe this is correct for the stock R53:

• lobe lift: Intake .202", Exhaust .217"
• valve lift: Intake .333" Exhaust .310"

Also, the stock cam base circle diameter is 1.185" diameter. (On a regrind, this is ground smaller in order to create more lift. But you can quickly run-out of adjustment range in the hydraulic cam adjusters when you reduce the cam base circle.)

 

Cool. Thank you