This post is phenomenal. I understood the concept of engines (mainly because I'm addicted to motoGP and it baffles me how those machines stick 238hp rwhp from a liter bike to the pavement) BUT I have 2 questions. "Hot rodding" the engine by adding more air and fuel will for sure reduce the engine longevity. But look at Ducati and KTM, hell even the M109r, they all run over 12:1 compression on their twins and with the proper (yet extra high maintenance factor) they run for over 100k miles producing 130hp-170hp, the vtx1800 has 9:1. I see what Honda did, mainly because I owned a civic SI and I currently work for their largest competitor (Toyota) their missive was efficient and idiot proof but yet fun, I don't think any of us are idiots so it would be like a slap to (soichiro) honda's face NOT to modify this behemoth of an engine to its full potential!
Which leads to my second question, I have been thinking about what to do to my bike since I bought it last week, I love the power but it's alllllmost where i want it, sportbike wise this vtx is allllmost there 0-60 wise. BTW I'm about to throw some numbers out there that are based on the "measured" rwhp of this machine from the factory (I only have 11,000 miles on my bike so the motor is barely broke in anyways) so I'm reading 97rwhp does that sound about right? Or is it less? Power to weight wise; me on my super sport I was achieving 1hp per 5.8lbs of mass which personally I thought was ridiculously fast. With the vtx I'm somewhere around 9lbs/hp. From what I read on the site already if you are pushing over 150rwhp you are setting the final drive up for failure. So I've set my goal to let's say 125rwhp, which is do-able and I feel I would be completely satisfied with that.
So far the bike I bought had a k/n carbon filter, kyruakyn (sp?) hypercharger, "bud" pipes and other rider friendly accessories, I'm about to do a full over haul on the engine fluids, just changed the oil to Lucas oil 10w-40 semi synthetic which made it shift way better than the supposed HP oil the previous owner had in it. So with these mods MAYBE I'm make 100rwhp? 105 if I wish reeeaaaal hard. What gains would I see from the following; stage 2 "street-strip mill/port/polish to the cylinder head and intake, PCM 3, some one mentioned aggressive cam? (Yikes that must be expensive), what about larger valves? Would I achieve 125rwhp by using a combination of these? how much would all that extra fuel and air filling the cylinder affect the compression ratio??
I see this post is ridiculously old but you guys know your stuff so help a guy out haha