It won't be correct. Exhaust resonance and tuning will be a lot different than the Termi exhaust. People think that just removing restriction makes things flow more freely, but there are a ton of dynamic forces and factors that have to be taken into consideration when revamping an exhaust system. Just removing restrictions will make it run leaner, but WHERE in the RPM range will that occur, and how much of a change will there be? You can try different MAP's, and use the 'seat of the pants' tuning method, but the only way to do it properly is to hook up some A/F sensors and let the Auto Tune/Roll-on functions do their job. This will work great up to about 50% throttle settings, making multiple roll-on tuning passes while holding the brakes to slow the acceleration through each fuel cell on the MAP at each throttle setting on the MAP, but above 50% you really need a Dyno to get it correct because no matter how hard you brake, the bike is going to still try to accelerate like crazy and you are going to reach very illegal speeds very quickly.
Also, you seem to be riding an 899 (nick?) so that's an entirely different ballgame compared to larger twins. I'd start with the provided MAP's, one at a time, and test them for rideability and throttle response throughout the RPM range in 4th,5th or 6th gear, starting at about 2800-3000 rpm, and see if the bike bogs anywhere through the throttle setting and at what rpm it occurs. The Termi will probably be closer than most of the other options, but it's hard to tell. Also, pull up the fuel MAP's for the 1199, 1299, and 959, and see if the numbers are different for the same style of exhaust. You might be better off using a 959 tune instead of the 899 tunes . It's the same basic engine, with different bore/stroke numbers, but the intake/exhaust flows will correspondingly increase with larger displacements, so the 959 tuning might be more beneficial, and keep the engine a bit richer due to a higher fuel flow, than the 899 MAP's will.
