Here comes the POWAHHH! Well, at least a few more that is. Finally made the jump to the real power gains, the CAMSHAFT!
The WHY:
So we've only done bolt-on modifications to this point on the 2019 Honda Monkey and while they've been fun, they haven't completely transformed the bike in terms of horsepower. Our Yoshimura exhaust, MNNTHBX MTake Intake, and Bazzaz Z-FI fuel controller was a nice package to get a bit more throttle response and sound (both from intake and exhaust), while the Bazzaz ensured those two air increasing parts got the additional fuel they needed. Each one of these parts won't provide much in their own in terms of horsepower, but when packaged together, will give the bike a few more horsepower and provide a punchier lower-RPM range boost, but still falling flat as you top out 4th gear and struggle to reach that coveted 70-mph mark. So how do we approach a faster top-end? The first step in that direction is to start thinking cams!
The HOW:
A camshaft controls the height in which the intake and exhaust valves open, how long they stay open, and the timing of it all. It's a carefully calculated science. The OEM cam is going to be the "best common blend" of low-end response and emissions friendliness. In other words, it's certainly not optimized for performance and there is always room to work with within the stock valvetrain and how far you can push your valves. And with such a small bike with so little horsepower to work with, the stock cam will be heavily biased towards getting the bike moving and low-end response. An aftermarket cam will have different "profiles" than the stock cam, which almost always means they will have a taller lobe, which controls how far the valves open. A performance cam with a taller lobe height profile allows the valves to open more than the stock profile, allowing more air into - and out of - the cylinder head). The more air we push in and out, the more potential to make horsepower. Along with height, we have "duration". Duration is how long the valves stay open. Keeping the valves open longer allows the intake cycle to blend into the exhaust cycle, and vice-versa. Sometimes this is good for emissions and efficiency, keeping the air/fuel ratio biased towards a leaner, more efficient burning mixture. Changing the duration with an aftermarket cam allows the charge (intake) and exhaust to be altered, and with it, allow more air and fuel to be pulled into the charge cycle and held in the cylinder longer, creating a stronger combustion cycle, producing more horsepower.
The RESULTS:
Well, that will have to wait for the follow-up Ride/Review video! I can tell you that the bike has a noticeably faster top-speed. I was afraid of losing low-RPM horsepower because of all the facts above, but with my 14T/36 gearing, the low-end was already artificially boosted and I experienced absolutely no loss in low-end feel!
Where I got it:
https://www.tbparts.com/product/tb-high-performance-camshaft-2/