Unless dedicated for a tractor application-turbine's are not a good choice for something that's got to be asked to make a lot of shaft speed changes. Turbines excel in applications that need a constant load and constant shaft speed, such as generators, pumps, and aircraft.
Also, most of the time, turbines don't do well as far as throttle "response". They don't increase speed nearly as fast as piston engines do when the throttle is applied, hence most of the reason that they're really better used for constant speed/load applications.
I have ridden a project bike that had a little heli engine, Allison as I recall (been about 15 years ago or so), and while it was cool, silky smooth, it was gutless for a motorcycle. Yes it would probably go really fast if I'd allowed it to continue to accelerate, but it was so slow in accelerating-in comparison to a 4 cylinder piston engine of approx 100hp, that it was honestly a slug. But it sure sounded cool, and I still want one.