The dyno sheet reflects a good torque gain in the low to mid range. How ever the HP claims are not quite correct the gain at peak is 1.7HP & the mid range is around the 2hp mark not 3HP.
http://www.mr2ownersclub.com/converter.htm
I also wonder if this bike had a PCIII fitted at the time of the dyno run, with this HP result on a XTX/R you would need a fueling device + both filters + cans.
This Can shows a good gain over all & is what I would expect from the type of system.