Fast Bike Magazine paid a visit to James at JHS Racing for a Dyno test and they found a clear dip in both power and torque on the Dyno chart along with a soft rev limiter.
At 5000 rpm on full throttle is where the air box valve opens up thus the dip in the dyno chart, because the air speed is changing. Once the air box valve opens up, you can see the horsepower start to climb but the exit valve in the exhaust pipe is still not fully open at that point so around 7000-7250 rpm is where it starts to dip off in both power and torque before it’s on the increase again. James describes it to be similar to a “kick”, something you can feel. When everything is wide open, you will get a nice power line until you hit the average maximum power of 132.44 and maybe even more depending on the day and weather.
What’s interesting is that between 3.5 and 5.5 RPMs the Panigale 899 actually produces more power, at least until the rpm picks up but there’s still that 10hp deficit in the 959 before then. When they compared the 959’s torque to the 999, it just gets trounced. That’s due to the difference in airflow between the 3 motorcycles. The 959 has an oval throttle body while the 999 had a circular one which allows for a higher airflow velocity than the 959. That’s why the 959 has air valves, to try and keep up the air speed going into the engine.
Something else of note is the use of soft rev limiter instead of a harsh one. A soft rev limiter will stop the spark a little bit above the bike’s pre-set level and then reinstate it below that level. At that point, your bike will feel like it just won’t rev any higher. A hard rev limiter will stop the spark above the pre-set level and only reinstate it when the revs are dropped to around 250 below the valve limit, this will feel like your engine has been cut. Normally, manufacturers implement a hard rev limiter when they have an rpm issue but there is potential for more power with a soft rev limiter.
James thinks the 959 has potential to overcome the low rpm stagnation and increase its maximum power with a full system, air box mods, etc. You could even apply the same tuning concepts for the 999 onto the 959.