1) Can you corrolate BTU's to horsepower?
Relating heat to horsepower requires resolving all of the variables; compression ratio, valve timing, ignition timing, etc. Brake Mean Effective Pressure (BMEP) is another very effective yardstick for comparing the performance of one engine to another. Comparing a 300 cubic inch engine to a 400 inch engine is difficult. Using BMEP allows you to compare how much pressure is being developed. The definition of BMEP is: the average (mean) pressure which, if imposed on the pistons uniformly from the top to the bottom of each power stroke, would produce the measured (brake) power output. The absolute answer is that until you put it on the dyno, you don't know, and until you take it down the course in real race conditions, you'll never figure it out.
2) How much more horsepower does nitrous oxide add to an engine when it is being sprayed?
Horsepower is the answer we are most familiar with, but unless you have dyno readings for a particular setup it is mostly advertising. Nitrous is frequently advertised as "75 horsepower" when what they really mean is there is the possible, maybe, kinda sorta, if you play your cards right possiblity of having that kind of power increase. Since most of their customers don't have access to a dyno, no one really knows if that is close or not. Unless you match the fuel to get the correct ratio you can't get maximum effiency. The difficulty lies in figuring out where on earth to start. The seat-of-the-pants method is to always start on the rich side and work back to the correct ratio, determined by checking the plug color. If you have a mass air flow sensor your life gets a little easier, but this is why the guys with little experience have it so hard. "I really want maximum horsepower, but don't want to blow it up."
3) In aviation we suck on 100% oyxgen when up on altitudes. Would setting up a 100% oxygen bottle to your bike make any difference to mixture power if pure O2 was released into air intake just before the "big mile"?
It sure would, if you could keep it from torching a hole in the piston. Nitrous oxide has the advantage of releasing oxygen in the heat of combustion, where pure O2 produces lots of heat NOW. Not that it couldn't be used, but control is difficult. O2 is easily available in compressed form, not liquid. Nitrous is a liquid, and the difference is the amount of power you can put in a compressed bottle.
4) From your write-up it appears there are only a handful of people in each state that know about and that can safely work with nitromethane. Can I assume that to be correct?
Only from the stand point that not that many people ever run nitromethane. Most racing is gasoline oriented. Drag racing and land speed racing are the two biggest forms of racing that use it. RC cars run 20% nitromethane all the time.
5) Can I also assume that once you set up your bike for nitro-- you can just about forget riding it around town?
You haven't priced nitromethane, have you?
At $40-50 a gallon, and using 5 times as much . . .
Did I say something about the smell of nitrous oxide? I didn't think I did. Nitromethane on the other hand . . well I'm addicted to the smell. It's no doubt poison, but when you smell a top fuel engine light off . . . AHHHHHHH.
I worked with a fuel genius in the late 60's. Have you ever tried oil of wintergreen? The smell when burned is pretty exotic. Makes a good buffer for methanol/nitromethane too.
Should we discuss hydrazine? Also was popular in the late 60's. Still popular as rocket fuel. With nitromethane it produced tons of power. If you let it sit for a few days it went from a pretty decent fuel to a Class A explosive. I wonder why they banned it?
