Hey Banditone1250s...I'll take a short stab at this.
Engines tuned for racetracks are usually tuned for max horsepower. Since torque is the work done and horsepower is the rate of doing work, a bike that creates its torque at higher rpms results in more horsepower. Higher horsepower tends to result in more acceleration and top speed.
A "detuned" bike, usually means the manuafacturer has altered things like cam lift and duration, carb or fuel injection throat size, length of intake, size and length of exhaust, etc. to make the max torque occur at a lower rpm, meaning LESS horsepower. Why? It make the bike way easier to ride in most situations. Better low rpm acceleration, or better roll on performance. Emissions can play a role as well.
Specifically to the 1st, 2nd and 2.5 SACS engine Bandits, they are basically altered GSXR 750 and 1100 engines origionally designed in the mid to late 1980's. On this site you can find lots of guys who have "retuned" their Bandits to make more horsepower. One of the easiest and largest benifits has come from "de-resticting" the intake and exhaust and perfecting the jetting. On either the 600 or 1200 this tends to add torque across most of the rpm range, meaning more horsepower everywhere.
For guys that want even more horsepower, it is usually easier to get by moving the max torque up the rpm band. For example, after a pipe and jet kit, a change to different cams in the 1200 allows it to rev higher, usually in conjunction with additional airbox/air filter mods to allow more air in.
Other ways to make more power are:
1. Increase displacement, usually via a big bore kit. Larger engine usually means more torque, espcially at lower rpms.
2. Higher compression, via different pistons. Bigger bang can result in higher torque.
3. Porting & valves. Smoothing/reshaping intake/exhaust ports can decrease friction/increase air flow. Special angles on the valve face/seats can do the same. Larger valves can allow more air in/out.
For your 1250 Water cooled, the empirical data is not there yet, though coming fast. Typically an lower restriction exhaust combined with adjusting the fuel mixture will result in more high rpm power. This will be done with a "chip" or software change to alter the fuel injection. May or may not need a change to the air filter/air box. Don't yet know if this will change any of the existing low rpm characteristics, but with the massive torque rise at low rpm of the Bandit 1250, you likely would not notice a slight shift.
I hope this helps...
