If you want to see the envelope pushed? checkout this video.
http://techwest.ipower.com/mpwr20/MAXPWRwebpromo.wmv
System used: MAXPWR Voltage Converter MSD®Ignition 6600 HVC, MSD®Ignition 8250 coil. 12vdc vs 20vdc. Interested checkout
www.techwestracing.com/page21