You don't need a fully modified...
You don't need a fully modified beast to start racing; a mostly stock bike with the minimum of modifications will be stone-reliable and plenty quick enough. Check with your local racing organization for required prep-work, as it varies from club to club.
We know how competitive things can get at a track day. The bragging rights for passing your buddy can last for weeks or even months, and there is definitely some satisfaction at seeing your name on top of the time sheets some organizations post. We even have a group of friends vying for "the cup" awarded to the fastest among them. But the truth is that friendly competition is just that; nothing can compare to the real thing, and gridding up for a proper race is a completely different experience. Not only will an actual race determine just how fast you are among your peers, but also it will improve your riding skills at an immensely quicker rate.
Your first race can be a stressful ordeal, but with some preparation and the right approach it will be enjoyable and an experience you'll remember for a long time. In fact, few of us that have raced will ever forget that first event. Chances are good that a handful of racers are taking part in your regular track-day events, and they will most likely be glad to answer questions about how to get started - such as what organizations run events at your tracks, and what their specific requirements are for preparing your bike and signing up.
Here is one racing rush you...
Here is one racing rush you won't get at a track day: There is always plenty of excitement at the start, and it usually ramps up from there.
First, the preparation. In order to race, you must have a competition license issued by the organization you choose to race with. Some organizations will grant you a license based on participation in an accredited school; others will require you to attend a specific new-racer's school run in conjunction with race events. For example, first-time racers with WSMC (Willow Springs Motorcycle Club) must attend the new racer's school held on the Saturday of race weekends. Aspiring WERA (Western Eastern Roadracing Association) racers can obtain a provisional novice license by completing a recognized school such as the California Superbike School. Check with your racing organization to find the necessary requirements; if you've attended a school recently your license may be just a matter of paperwork. Some track-day organizations offer instruction that may be accepted by the racing club; others run laid-back races as part of their program that can help you get your racing feet wet.
Your riding gear should be in top shape if you plan on racing. Simply put, you will crash at some point, and it's not worth skimping on protective apparel. While some track-day providers can be lackadaisical when it comes to gear, you'll have to present at least your helmet at tech inspection prior to your race and it will have to meet a safety standard other than DOT as well as being reasonably new. Other must-haves include one-piece leathers, boots, gloves and a back protector, and at least consider a chest protector and ear plugs.
Prepping your bike for racing is considerably more involved than for a track day. At a bare minimum, plan on removing or taping the lights, replacing the coolant with water and safety-wiring some hardware. Most clubs require a lower fairing that will hold fluid, and that will mean new bodywork or some improvisation. And, of course, number plates with your assigned competition number. Some crash protectors and sturdy engine covers would be a worthwhile investment. Definitely check your club's rulebook for the necessary requirements, as some require more elaborate or specific modifications. Still, you may be surprised to find how little time is required to completely prep your bike. Be absolutely certain everything is ready before you show up at the track; you'll have to pass through tech inspection, and missing the first practice session to safety-wire a bolt you missed is a frustrating start.
Your racecraft will come into...
Your racecraft will come into play when dicing with other riders. The less you have to concentrate on your actual riding, the more you can focus on how to beat the other riders to the flag.
The major difference between riding at a track day and racing is that, instead of staying clear of other riders and avoiding traffic, you'll be forced into close quarters right from the start. (And speaking of the start, that is one thing to practice at least a couple of times before the real thing.) Dealing with other riders and the dynamics of the race will certainly distract you from focusing on your riding skills, and the more second-nature your skills are, the more attention you can devote to the race itself. This is racecraft, the major distinction that separates racing from simply riding around with your buddies.
There are two sides to the racecraft coin. On one side is how well you can use practice to set up your bike and learn a track, so that you are not distracted during the race. You want to be focused on how to pass the rider ahead rather than why your steering is a bit lazy or how to negotiate a particular chicane. Many riders find that at the end of a race they can't recall much of the actual riding, their focus on the racing is so intense. That said, the race is where you'll learn the most and find your skills naturally improving: You'll pick up lines and other tips from the riders you're dicing with, and - of course - competition and adrenaline naturally lead us to take more risks. After the race, go over events in your mind to find what you did to go two seconds per lap faster than you did in practice, and make a conscious effort to use those skills when you're on the track again.
Bragging rights for track-day...
Bragging rights for track-day lap times with your buddies is one thing. Winning a race and taking the trophy home for all to see is another.
On the other side of the racecraft coin is something that may be unexpected. It's possible to become so caught up in a race that you forget certain riding skills or revert to bad habits, and this is something to be aware of. For example, you know that a certain body position works better and use that regularly at track days. But in a race you find yourself using a less effective body position, even though you know it is holding you back. The problem here is twofold: Not only is your body position slowing you down, but now it is also distracting you during the race. It all comes back to how well you can absorb a skill into your repertoire and make it second-nature. Again, think about your riding after a race and whether any skills fell by the wayside in the heat of battle.
First-time racers often get stuck with the notion that they have to start at the top level with their equipment, but that is definitely not the case. You don't need new tires for every session, a fully built motor or all the trimmings in your pit. Some racers lose sight of the fact that the riding part is most important, and end up worrying about other things when they're on the track: Are my shiny new rearsets adjusted right? Are the slicks properly up to temperature? I hope I don't crash and wreck this nice paint job. Those worries can often turn into excuses, and from there it's easy to lose focus of a racing program's important aspects. Concentrate on the necessities at first, get as much track time as you can, and modify your bike as you gain speed and find it necessary.
Most importantly, we usually start racing because it's fun. Take the right approach without overextending your resources (in terms of both time and money), and the fun will continue while you find your skills - and results - improving each time out.