10 degrees BTDC is stock. The car feels a little peppier at 12 or even 14 degrees (listen for pinging or run premium at 14). You have to jump the "gnd" and "ten" connectors with a paper clip when checking the timing (under the lid of the black "diagnostic" connector). You'll know you jumped the right two pins if you hear a slight idle change and the timing mark stops jumping around.
The 2008 Mazda MX-5-Miata has 16 valves.
The 2004 Mazda MX-5-Miata has 16 valves.
The 2006 Mazda MX-5-Miata has 16 valves.
The 2002 Mazda MX-5-Miata has 16 valves.
The 2014 Mazda MX-5-Miata has 16 valves.
The 2013 Mazda MX-5-Miata has 16 valves.
The 2005 Mazda MX-5-Miata has 16 valves.
The 2011 Mazda MX-5-Miata has 16 valves.
The 2007 Mazda MX-5-Miata has 16 valves.
The 2010 Mazda MX-5-Miata has 16 valves.
The 2012 Mazda MX-5-Miata has 16 valves.
The 2001 Mazda MX-5-Miata has 16 valves.