What is
VTEC?
VTEC stands for Variable Timing and Lift
Electronic Control System. It was designed to resolve once and for
all the usual compromise engine designers have traditionally been
forced to make between low-speed torque and high-end horsepower. It
lets the engine breathe according to its needs.
Engine breathing is analogous to the breathing of any living
organism. At rest, the lungs take in the necessary amount of air
for normal function. When running, the lungs and heart work faster
to supply more oxygen to the system. Engines can't do that because
their breathing apparatus (comprised intake maifolds, intake
runners, valves, valve lift and throttle bores) is fixed. Not so
with VTEC.
Using an innovative arrangement of three intake and exhaust lobes
per cylinder, VTEC increases both valve lift and valve opening
duration as the engine climbs through the rpm band. By varying
valve lift and timing, the engine can aspirate more air when it
needs it at high speed operation. It boosts power without resorting
to the complex and sometimes overstressed system of turbocharging
or supercharging.It's an elegant and organic solution to a problem
that has plagued engine designers for generations, and exemplifies
the Acura approach to engineering. Simplicity, elegance and
function.
How to tell when VTEC is
kicking in?
Watch your oil pressure gauge as you rev up through 5800 RPM. The
VTEC system consumes a significant amount of oil flow when it is
activated, and you can watch your needle FALL a couple of notches
as the revs climb through that point.
VTEC factoid-of-the-week: Valve timing change conditions that must
be met include 5 km/h (3 mph) or faster and 60 degrees C (140 deg
F) or faster.
The VTEC technology is employed in the following Acura
Models:
Acura Integra GS-R
1.8 liter, 4-cylinder, 16-valve DOHC VTEC
Acura 3.0 CL
3.0 liter, 24-valve SOHC V6 VTEC
2.2 liter, 16-valve SOHC inline 4-cylinder VTEC
Acura NSX
Manual - 3.2 liter, DOHC 24-valve V6 VTEC
Automatic- 3.0 liter, DOHC 24-valve V6 VTEC
