DYNO FILES: 2015 HARLEY-DAVIDSON STREET 750Let’s see how Harley’s all-new Revolution X V-twin compares against its competitors on the Cycle World dyno.
April 2, 2014 By 13 Comments
While riding the 2015 Street 750 at a press event staged not far from Cycle World’s Irvine, California, headquarters, I seized the opportunity to swing by the office and roll this all-new 503-lb. Harley onto our Dynojet Model 250 dyno. You may have seen the video. At any rate, this pre-production example of Milwaukee’s new 60-degree, liquid-cooled Revolution X V-twin produced impressive results, which begs the question: How does this new Harley powerplant, with single overhead camshafts operating four valves per cylinder, compare to some of its potential rivals?
Harley-Davidson Street 750 versus Harley-Davidson Iron 883
In racing, it’s said that beating one’s teammate is priority number one. That stated, let’s study this dyno graph overlay comparing the Street 750 with the Iron 883. What you should notice are the very different power-delivery characteristics of these stablemates. The 883 builds torque right off the bottom, and it maintains a very smooth linear output throughout its rev range. The Street has a much wider plateau of torque, and when the 883 hits is limiter at around 6,000 rpm, the Street 750’s horsepower is still rising sharply, peaking at 7970 rpm. Perhaps some of the wrinkles evident in the Street 750’s torque curve will get ironed out as final production-spec fuel mapping gets set.
Harley-Davidson Street 750 versus Star Bolt
The air-cooled 942cc V-twin in Yamaha’s Star Bolt is tuned with an even greater emphasis on bottom-end torque production. As you can see here, this does come at the expense of revs, however. The Bolt engine, like the Iron 883 motor, has more torque in a narrower band than the Street 750 V-twin, which produces good horsepower and torque all the way to almost 8,000 rpm.
Harley-Davidson Street 750 versus Ducati Monster 696
The opposite holds true for the Ducati Monster 696. This sporting Italian V-twin has a torque spread clearly weighted more toward the upper half of its rev range.The Harley has more torque until just above 6,000 rpm, where the Ducati’s ability to rev starts to give it an advantage. It’s similar with horsepower, the Harley having a clear edge that lasts until approximately 6,250 rpm, at which point the air-cooled Duc shows off a steeper curve that lasts significantly longer than the Harley’s.
Harley-Davidson Street 750 versus Honda NC700X
These remarkably similar power curves show that the Honda NC700X, which is well known for its ultra linear power delivery, is a close match for the Street 750. But there’s an important point here: The Honda is tuned with maximum fuel economy in mind, and, as such, it’s limited to about 6,500 rpm. The Harley, as you can see, has an additional 1,500 rpm of head room to make more peak power.