Ever heard your fanatic Honda buddy say, “VTEC just kicked in!” and not had a clue what they’re talking about? At this point, VTEC almost feels like one of those memes that’s been parroted so many times that nobody remembers what it means. Let’s explore.
What exactly is VTEC? As an acronym, it stands for Variable Valve Timing and Lift Electronic Control. Perhaps Honda should have called it VVTaLEC, but that’s not nearly as catchy, is it? Functionally, it’s a technology that enables an engine to breathe more freely at higher rpm to increase performance.
Engine Lessons
An internal combustion engine is effectively a very complicated air pump. The more air it can suck in and force out, the more fuel it can mix with that air and the bigger explosions (read: more power) it can make. Air enters and exits the cylinder through valves on the intake and exhaust sides. Those valves are controlled by rotating camshafts with lobes that push the valves open and valve springs that force them closed again.
Altering the height and width of the lobes on the camshaft will change how long the valves open and how far they open. Larger, longer valve openings mean more airflow and more power. So why isn’t every engine fitted with huge cams? Problem is, an aggressive cam is inefficient at low rpm because it prioritizes the volume of air rather than its pressure. Smaller amounts of air moving at a higher velocity (as a result of shorter, smaller valve openings) combine more evenly with the fuel and burn more efficiently.
To solve the problem, Honda developed VTEC to enable its engines to run a lower, more efficient cam profile at lower rpm and a higher, more aggressive cam profile higher in the rev range to maximize power. At a certain rpm, hydraulic pressure in the engine would reach a point at which it would actuate a selector pin, engaging the higher cam and enabling maximum performance.
Drive VTEC, Love VTEC
VTEC made its North American debut in the 3.0-liter V-6 mounted in the middle of the first-generation 1991 Acura NSX. By 1999, though, Honda’s trademark tech had trickled down all the way down to the humble (and much more accessible) Civic. Specifically, the Civic Si.
Honda was kind enough to lend us a spotless, bone-stock 1999 Civic Si in Electron Blue for Radwood L.A., and it was the perfect way to refamiliarize myself with the engine technology that birthed an entire generation of Honda fans. The Si is powered by Honda’s B16A2 engine, a 1.6-liter inline-four that develops 160 hp at 7,600 rpm and 111 lb-ft of torque. Sure, the 1.5-liter turbo-four in the current-gen Civic makes better numbers than those, but to achieve 100 hp per liter from a naturally aspirated engine is a monumental achievement that few cars achieve today and even fewer did 20 years ago.
It’s a wonderful little car to drive. Curb weight is a featherlight 2,600 pounds, and visibility is panoramically fantastic thanks to slim pillars, big windows, and a low hood. But the characteristic that defines this 20-year-old Civic’s driving experience is without question the VTEC cam changeover that takes place when the tachometer swings past 5,600 rpm.
Exploring the last 2,500 rpm of this engine is like poking at a dormant volcano begging to erupt. It’s as if you discovered another 3 inches of gas pedal travel and could push the pedal straight through the floorboard. A B16A2 dyno chart shows exactly how drastic the changeover can be.
Even a week later, I’m still thinking about this engine. How docile and pedestrian it felt trundling around my neighborhood between stop signs but how raucous and mechanical and inspired it was once I crossed that threshold into the higher reaches of its powerband. And what’s special about this car is that the power is accessible enough that you can use it just about anywhere. It’s possible to experience VTEC in first and second gear below most highway speed limits. If you drive like I do, everywhere you go you’ll be revving this engine to the moon and grinning ear to ear.
All hail VTEC. Long may it reign.
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Source: WORLD NEWS
