Glossary continued

MIVEC
VVTi
CAMPRO- CPS
VTEC

MIVEC - Mitsubishi Innovative Valva Timing Electronic Control System
VVTi - Variable Valve Timing with Inteligence
CAMPRO - CPS - Cam Profile Switching
VTEC - Variable Valve Timing and Electronic Lift Control.


I'm sure you've heard of these acronyms before whether they are on the back of the car or perhaps in the broshure.
Some mitsubishi cars come with stickers showing off the MIVEC apparently under the hood.
VVti you'll see them on toyota's and peroduas.
Campro CPS' you'll find on Waja's and Gen2's

and of course the VTEC you'll find plastered at the back of a Honda City, Civic, Accord, CRV, Legend and of course the S2000.

Just what the heck is the V-T-E-C for? No its not Very high Tech.

Variable Valve timing
simply means that the valves (the bits that allow air to come in the engine so that fuel can burn)
will open and close variably.

electronic Lift control
The valves can be opened (or lifted) for increased periods.

Why?
Read on

When you drive at low speed, i.e. around 3000 rpm, and not accelerating much, the engine is spinning at 3000 revs per minute.
Thats 50 revs per seconds.

Meaning 1 rev takes 0.02 seconds!

Remember there are 4 steps? Push Bang Blow Suck?
the valve only gets a chance to open at Push.
Therefore the valve is opened for only 0.02/4 seconds = 0.005 seconds!!!

In doesnt take a genious to realise that, if the engine is spinning at 6000 rpm (2 x 3000rpm), you are going faster, and therefore

the valve is opened for only 0.0025 (half of 0.005) seconds!

Please tell me, if the valve is opening for such a short time, can you really get so much air inside?
The answer is no.
Without air, the engine will choke.

Therefore the VTEC is there to tell the engine
KEEP THE DAMN VALVE OPENED LONGER BUT STILL MAINTAIN 6000 RPM.

So more air comes in.
YAY!

And that my friends
is the beauty of VTEC!