Can somebody explain VTEC like I'm 5 years old? I just read the wikipedia and I did understand... the words. However I think I misunderstood the significance of Variable Valve Timing and Lift Electronic Control ("VVTLEC?").

Particularly, can you explain the specific type of VTEC used in the 2015 Fit? It seems like there are a few variants.

Thanks! Obligatory this guy ->

The forum Auto-corrected my title to Vtech...

 

Explain like you're 5?

When you are just driving normally the engine is efficient, when you open the throttle wide enough and RPM is above a set point (on the GE it is 5500, I don't know where the new 2015's motor is set to) the engine settings change to output more power.

This way you get good gas mileage around town and more power when you need it. That's the basic principle.

The 2015 Fit uses i-VTEC.

 

It makes your car go Voom Voom!!

 

lmao! you seem to have a lot of experience dealing with kids.

 

Basically VTEC is like having two cars in one. How? Well lets compare two types of cars; a muscle car and a high revving sports car. The muscle car has a camshaft designed to give it low end off the line power but it maxs out at high RPM and loses its speed. Then we got the sports car, slow off the line but has a camshaft designed for high RPM power. Once it gets into the high RPM range it takes off past the muscle car.

So, how can we have two engines in one? VTEC works like this: A VTEC engine has a camshaft with different settings for low and high RPMs. When the ECU senses the car hits a certain RPM it sends a signal to the VTEC Solenoid. This solenoid used oil to slide a pin to adjust the camshaft to different settings. So at low RPMs the camshaft is set to certain specs to get off the line, once the RPMs get high enough the ECU activates the VTEC controller which uses engine oil pressure to slide a pin to adjust the camshaft to the high end specs. Then the VTEC kicks in yo!

Hope this info helps.

 

I would say it like this if I was telling a kindergartner, lol.....

A camshaft rotates and is responsible for opening and closing valves. Valves let air and fuel into the engine and then let air back out of the engine. At lower engine speeds the camshaft opens the valves normally letting the regular amount of air and fuel in. Then, at higher engine speeds the camshafts allow the the valves to stay open longer/lift higher allowing more air and fuel in than normal, making bigger explosions and producing more power.

 

Great explanation but you need some sound effects to go with that. "Explosions" = Big Boom! LOL.

 

There are many 'trade names' (VTEC for example) to describe the same function: to vary the time the intake and exhaust valves to open and close to provide the best filling of combustion chambers or let combustion gas escape. At low rpm the valves need less time open and at high rpm they need to be open longer and further off the seats so the fuel air mixture gets in and combustion products out better and produce more power. Velocity of the two strwams is the key.MPG is controlled by the amount of gas squirted into the air flowing into the combustion chamber based on the measurement of air flow.
Honda does it with two different camshafts on both intake and exhaust one for lower speed and the second for higher speeds. The camshafts slide back and forther controlled by a solenoid that pushes them back an forth.
Thats a little simified but the idea is there in principle.
And yes, some engines only control one camshaft, be it intake or exhaust.
That help?