"Car Tech 101: Demystifying the mythical VTEC"
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Cooley On Cars
Cooley On Cars
Car Tech 101: Demystifying the mythical VTEC
Now VTEC is a tortured acronym for Variable Valve Timing and Lift Electronic Control.
You kind of have to pick and choose your letters to get VTEC out of that.
But Honda did and we're glad they did.
Because VTEC came along before most companies had any kind of variable valve timing.
They all do But when VTEC came along, super exotic and with three huge wins.
It gave Honda v series engines something around a 100 horsepower per liter, that's a holy grail in in this business, it gave them bulletproof internal, these were not finicky engines and delivering 30 mpg in the real world.
All of a sudden Camaros and Mustangs on the street were getting heat from Civics.
To get inside Vtek we took everyone's advice and dropped in at Blacktrax Performance in Silicon Valley where cofounder Jei Chang loves and understands these motors.
The feeling you get as a driver when [UNKNOWN] kicks in.
I mean, you literally go from a very normal daily driving commuting car to an animal at like 5,000 RPMs.
I would say at least 5% of Honda buyers have no clue what they just bought.
We have purchased Honda S2000s from, let's say, a retired woman who liked to drive with the top down at the beach, never a day hit six thousand rpm v-tec and then one of my guys takes the car for a test drive, puts her in the passenger seat, hits v-tec and she starts screaming.
What the hell is that?
Now before we get into the guts of VTech, let's get into the guts of an automotive valve system to begin with.
You've got a cam shaft, which is this shaft here that runs, rotating with the crank shaft, that's part of the Engine's rotating internals.
On that cam shaft are these eccentrically shaped lobes.
You see how they're kinda pear shaped?
The high points of those lobes and the overall size of them tells you show long a valve's gonna open and how much it's gonna open, because when that turns it operates on this thing called a rocker.
It's like a little fulcrum.
And when it presses down as the lobing part comes around that pushes the fulcrum to open the valve which is this thing under the spring right here.
That either lets fuel and air in to become combusted or exhaust out to get rid of it.
This lobe is key because the size of it as well as the peakiness.
Of the pointy part tells you how long the valve is going to be open, and by that peakiness, how much it will open.
Shaping that lobe is key to the way engines breathe.
So, what is unusual about this cam?
Well, if you take a look here, this has got three cam lobes per cylinder on the
And these two right here we'll call them primary cam lobes.
This is what the engine operates off of at the lower RPMs.
Up to about five?
Oil pressure then travels through this rocker arm and pushes a pin out.
So that pin is gonna get pushed by that pin under high RPM pressure.
Under high RPM oil pressure.
All three were locked and now the Vtec load will be pushing these guys down.
So these outer guys used to operate independently on the low range load.
Lock them and they're slaves to the big load,
Correct.>> Now we're in [INAUDIBLE] and breathing good.
To hear and see the deck and operation, Jay put an admittedly heavily modified S2000 on their [UNKNOWN].
We're going to do a sweep, or wide open throttle pull, from about 2000 RPMs to about 8500 RPMs.
Currently, the tech is set at 3500 RPMs, so we should see a switchover, or hear a switchover, around that RPM.
At Buffalo raceway, it's the fastest S2000.
The guy in the car is Graham Downy.
He races that S2000 we just dynoed.
And it seems to be doing pretty well.
On the track it's excellent cuz we get to take advantage of that V-Tech and that V-Tech cam.
We're on the high cam almost all the time but We do cross over back into the low temps too.
Yeah, it's fun.
BMW Valvetronic and Porsche Variocam are among the systems that have come along since V-Tek to do about
Same thing but VTECH has a monopoly on low cost and efficient performance with a heritage and a meme.
The only valve technology in the world that has a meme.
Yeah, VTECH kicks in yo
No one says that about valve tronics
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