A bigger cam ,holds the valves open longer , reduces comp. ratio. The 2007 CVO { 110"} manual says , 200-220 cranking compression with comp. release closed , and they are running 214-218. That is NOT GOOD , my freinds. That is race bike comp. ! The S.E. 255 cams are ground by Andrews { John is a freind of mine} and they are NOT grinding them to the #s listed in the S.E. catalog. I put the Andrews 32H in my 2007 springer ,and it 'cooled' it down a BUNCH and has the same tq. { 110} but more hp. 90 vs 100 { no tune} Zippers air filter and 'home made' baffles {{cycle shack design} and now I put the TFI on it ,and it runs GREAT. Put the RUSH slip-ons on it and lost 8-11 tq. 2300- 3600 rpm. so I put my home made baffle back in and will dyno again soon. I have a contract with the 'local' H-D shop to use there 250 I dyno , FREE. I have been told ' I can tune a carb over the phone' BUT , this F.I. is new to me but after playing with this TFI , I am starting to like it. DEWEY