Lmario, as far as I know there hasn't been any '07's to play with yet, so yes, these numbers are my slightly optimistc expectations. HOWEVER, they are based on some experience.
I was a professional ASE certified auto tech for 28 years, been to school for different types of fuel injection and emissions. Granted, it's not motorcycle stuff, but it is related. I built and raced bikes in the 80's, mostly 4-in-lines, and a few 2-strokes. And I did a pretty good job opening up the potential on a '82 GPZ1100 with digital fuel-injection by putting a Kerker header on it, porting and polishing the head, and replacing the black box "chip" before they had the gadgets they do now where you can reprogram the computer and fine-tune the settings. Along with a few other minor changes, I remember getting about 20 more horses out of that beast.
Take the catalytic converter... it creates quite a bit of back pressure, which also affects the O2 sensor reading that feeds info to the computer. I'm making an educated guess here, but I'm expecting to get 5 to 7 horsepower by removing the stock can with the converter and replacing it with a low-pressure slip-on.
Now you have the secondary throttle plates, which are controlled by the computer and restrict air flow into the throttle-body which richens the mixture under certain conditions, to smooth out mid-range power, for example. By removing these plates, you eliminate any air-flow restrictions, which will richen the mixture across the board, therefore changing the O2 sensor readings which affect the computer. I figure this will get me another 3 to 5 horsepower, but will have driveability problems like popping on decelleration, abrupt power surges and the like. So...
To tie it all together you need to go into the computer with a UBS port-type reprogamming unit and tweak the settings for the new conditions created by the lack of back-pressure and unrestricted air-flow through the throttle bodies. Remember the computer also controls the ignition timing. The re-map will probably be good for around 7 to 10 more HP's and balance everything out smoothly.
So by adding it all up, I arrive at an estimate of 15 to 22 horsepower, which is less optimistc than my off-the-cuff original numbers of 20 t0 25, but I'd be pretty happy with that. And without having to get into the engine at all, and spending around $500 to $700 depending on which exhaust I use, and whatever it takes for the re-map.
These are relatively simple mods that most people can do themselves. If you can operate your home PC, you should be able to tweak the "black box" no problem. I just love digital fuel injection!
The '07 is supposed to be Euro-3 compliant, which means it's choked down pretty good. That and the fact that Suzuki puts out rather modest HP specs for insurance purposes, and justifying the "standard" status of the Bandit rather than putting it in the higher-risk "sportbike" category, it's my opinion that there is a huge amount of potential in this new bike that can be realized relatively easily simply by allowing the new 1250 engine to breath properly.
After that, if you want to get into the engine and spend bigger bucks, think about this: The stock cams are probably configured for low and mid-range torque, and the stock pistons are most likely lower-compression units designed for low-octane gas. Imagine what the right cams with some high-compression pistons would do on top of those extra 50 CC's.... another 15 to 20 HP's wouldn't be too much to expect, ya think?
