Is 68 horsepower too much muscle for a mere mortal? That’s 10 horses more than the most powerful 450 in its class—the KTM 450SXF. Funny thing is, the KTM 450SXF doesn’t feel as fast as it really is. Say what? Both the CRF450 and YZ450F feel more potent on the track than the orange machine. In a blind race test (we don’t recommend trying this at your local track), the average rider would not pick the KTM 450SXF as the most powerful bike in the pack. Why not? Because it rolls on smoothly and produces its power with a steady progression of vibes that build as the rpm climb.
THE SYSTEMS KX450F’S POWER-TO-WEIGHT RATIO IS GREATER THAN THAT OF THE FASTEST STREET-LEGAL CAR IN THE WORLD—THE 1200-HORSEPOWER BUGATTI VEYRON (ALTHOUGH TOP SPEED IS A LITTLE SHORT OF THE VEYRON’S 257 MPH).
KTM isn’t the first manufacturer to figure out that smooth is the name of the game in 450 racing. The days of hard-hitting, potent, rock-you-back-in-the-saddle powerbands are over. That may have worked in the two-stroke era, because smokers had to hit hard because of their short powerbands. And, with the average 250 two-stroke having only 48 horses, even Novices could manage to hang on to their output. But, if you had a Yamaha YZ250 two-stroke that punched out 58 horses or—in the case of our test bike—68 horses, all you’d be doing is wheelying and hanging on for dear life. You could never get a 68-horsepower two-stroke to put power to the ground with any predictability. It would be wasted power.
But, what KTM learned (and the other manufacturers are catching on to) is that you can make all the four-stroke power you want—if you make it smooth, manageable and easy to use. This is why KTM makes the most horsepower and the easiest-to-use power. It is the perfect combination.
Which leads to the questions that we wanted answered by Systems’ 68-horsepower KX450F: If 58 horses is good, is 68 horsepower better? Can the power be tailored to be both jet-assisted and electronically managed at the same time? Would it scare us or thrill us? The answers depend on the help of the ECU masterminds, because the bike’s electronics can be tuned to deliver flawless power at every throttle opening. If it’s too fast at 10-percent throttle, retard the ignition timing and add fuel. If it’s flat at 80-percent throttle, advance the ignition timing and add even more fuel. Sounds easy, right?
“BUT, WHAT KTM LEARNED (AND THE OTHER MANUFACTURERS ARE CATCHING ON TO) IS THAT YOU CAN MAKE ALL THE FOUR-STROKE POWER YOU WANT—IF YOU MAKE IT SMOOTH, MANAGEABLE AND EASY TO USE.”
C4MX builds engine packages for everyone from local racers to AMA Pros. They build Kawasaki of Canada’s factory KX450F engines, as well as powerplants for many 250 East/West Supercross privateers. Holeshot king Mike Alessi used C4MX’s 68-horsepower KX450F engine in the 2017 Canadian Nationals. And, as you probably guessed, Systems’ KX450F uses the exact same engine as the Canadian factory team.
After Systems and C4MX completed the build, MXA was the first to get it dirty. You know that feeling when you’re excited but scared at the same time? That is how we felt before riding Systems’ KX450F. The unknown is more than enough to get the adrenaline pumping.
To put the Systems KX450F’s 68 horsepower into perspective, the power-to-weight ratio is greater than that of the fastest street-legal car in the world—the 1200-horsepower Bugatti Veyron (although top speed is a little short of the Veyron’s 257 mph). It should be noted that even the works Kawasaki of Eli Tomac doesn’t try to harness this kind of power.
To get started, the MXA wrecking crew put our superhuman test riders on the Systems KX450F first. You know the kind of test riders we are talking about—those talented freaks who have never met a bike that was too powerful for them to manhandle. Sure enough, the freaks came back with grins from ear to ear. They said it was fast—really fast—but not too fast for them. They said that the rest of the MXA test riders would love it. We weren’t so sure. After all, talented freaks of nature aren’t usually the best test riders. They are best as test dummies who give us the thumbs up or thumbs down on how fast a bike is. From there, we rely on mere mortals to give us feedback.
The MXA mortals were next on the track. They rode with caution for the first few laps. Riding a gear high and coasting around the track, they immediately noticed that they didn’t have to downshift or use the clutch in the corners. The more their confidence grew, the more throttle they used. That is the beauty of having too much power—you always have power to spare.
Amazingly, the throttle was elevated to the highest level, but it wasn’t jerky. The midrange power was abrupt but still manageable. The more sensitive test riders could feel that the brute strength of the C4MX engine was being moderated and modulated by the tuning of the Vortex ignition, which was a good thing. Just when the test riders thought the Systems KX450F was about to rip their hands off the bars, the mapping would back it down a notch and put the power to the ground. Having massive amounts of power available but delivering it judiciously made the bike fast but not frightening. Oh, don’t get us wrong; when the bike hit the afterburners, it was almost too much power. Holding the throttle wide open in fourth gear made us believe that we could take a Veyron down the straights at Glen Helen. The more timid test riders put the Systems KX450F in one gear and didn’t touch the shifter again. It had enough power for the longest straights or the tightest turns sans shifting.
C4MX built a 68-horsepower beast and then tamed it. This is not the best engine for an Amateur racer. It has the potential to go faster than lightning—and it would be a shame to pull back on the reins. This engine deserves to be given its head and allowed to run free. It is an adrenaline junky’s dream machine.
SYSTEMS KX450F SUPPLIER LIST
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