The 6spds are about 1/2 second slower for each, track prep, temp, tire condtion all have a big influence and of course the driver is the biggest influence. Remember you just saw SRT8tech's best times not average times. Those are very good best times.
2010 Challenger R/T bought Oct. 2009 sold Dec 31, 2010
2010 Challenger SRT bought Dec. 31, 2010 sold Oct. 2013
2012 Challenger SRT bought Jan. 31, 2014