Celica Forums General Discussion Exterior VVTL-i VS. VTECH

I just got a 02 Celica GTS and and not sure of the difference between VVTL-i and VTECH? can anyone tell me the difference

Of course, it's quite complex when you get into the nuts and bolts of it, but the short version is quite simple.

The similarities end at the fact they both use variable lift in their head designs, but how they are controlled is quite different.

In a VTEC engine, the variable lift is actuated by an electric solenoid...

whereas in the 2ZZ engines, it is actuated by oil pressure, Via an oil control valve (which is a solenoid).

In a vtec, the high cam is on roller followers, on the 2ZZ, it has a solid follower.

In a vtec, the low and high cams act independantly, and are switched via the vtec solenoid; In the 2ZZ both low and high cam run simultaneously, and the lift doesn't come into play until oil pressure moves the lifter pins under the follower (at which time, the high cam profile has an effect on the valves)

So, in a VTEC engine, the lift is comtrolled by an electric solenoid and the high cam, and in the 2ZZ, lift is controled by oil pressure and the follower/lifter assembly.

In the 2ZZ, lift is truly variable, Unlike the VTEC that always has lift on the high cam.

This means, on the 2ZZ you can run on the high cam lobes with or without a variation in actual valve lift, while retaining the high-cam's valve timing profile... pretty neat, eh?

While honda's design may be a bit more practical, the toyota/yamaha design can be tuned to make power more accurately (IE, making the valve lift transition into the high cam rather than hit simultaneously with it)

Lowering lift engagement doesn't help on our 2ZZ, but raising it slightly seemed to make a difference for some experimental tuners out there, this is probably why the 2ZZ was designed this way, bumping up the valve lift AFTER the transition to the high cam makes more power.

Honda guys can select when the transition takes place, but when they get high cam, they get lift too, it makes the VTEC less tweakable in this regard.

both engines have their strong points, it depends on the individual to determine which one is best for them... I went with the 2ZZ-GE VVTL-I personally.

i know VTEC, but what is VTECH?

Uh, yeah, I was gonna say that...


One thing you can do is put a VTEC (and it is VTEC, not VTECH) badge on the exterior of your car and take a pic of it. Nothing is hotter than that.

lol... oh wellz you cant complain to the hp gain...

vtec comes on smoother but I still like the lift better... that thing was just amazing/addictive

What about i-VTEC, like what is in the RSX Type S?

More intelligent?

no different than the i in VVT-i or VVTL-i

my bad guy...i mean vtec, accidently put vtech, my mistake

thanks for the explaining that...very helpful

VTEC=VVT-i (Variable valve timing. It changes when the valves open)

iVTEC=VVTL-i (The above plus the valves open more at high revs)

From what I understand the RSX has lift.

Good thread

roger that

Yea, i-VTEC is a bit different, it has independant control of lift like the 2ZZ, but it's implemented differently. I don't know much about the i-VTEC beyond that, however it's about as new as the 2ZZ, so peeps are still learning about that one as well; Of course the Honda crowd has a leg up on us (with all that aftemarket support they have)

Don't know if it's any better than the toyota 2ZZ though,

The one in the RS-X type S makes about 200 crank HP, the Celica 2ZZ makes around 180 HP. The Civic Si version makes around 160 hp, the RSX base model makes similar power, maybe 170 (maybe more) HP if I recall, and the new Corolla XRS 2ZZ makes about 170 HP. Let's not forget the Elise and JDM version of the 2ZZ, which make power around 190-200 HP respectievly.

When you look at it this way, and put it in perspective, they are equally matched in terms of Performance, although the 2ZZ (generally) seems to put out higher numbers across the board. Why honda didn't use a more aggresive tune on the Si's motor is beyond me

VTECH -
It's VTEC guys.

100HP per liter n/a is awesome!

There's just a bit of mis-information that I'd like to straighten out:

Yes, VTEC is controlled by an electronic solenoid. When the engine gets to a certain rpm, the ECU sends a signal to the VTEC solenoid, but the actual switch from the low-cam to the high-cam is controlled by oil pressure, just like the Celica. The valves are made to follow the high-cam by oil pressure pushing a pin through all of the rockers so that two valves will follow one cam profile.

The low-cam and high-cam do not act independently. All the "high-cam" is is a different grind (higher lift and duration). There's three lobes per cylinder. Two for the low cam that are the same lift/duration, and a third (in the middle) that is the "high-cam." Thus, low-cam and high-cam are always rotating together.

The "i" in i-VTEC means, yes, intelligent. All it means is that the Intake cam has an oil pressure activated cam gear, always advancing and retarding the Intake cam timing according to the engine situation. And I believe, combatc87 that the i in i-VTEC is actually equal to the "VVT"--Variable Valve Timing. I'm not sure what the i in VVTL-i stands for.

The reason behind the Civic Si (and base RSX) having less power than it's Type-S brethren has nothing to do with the engine's tune; the engines are actually completely different. The Civic Si (and base RSX) actually do not have VTEC as most enthusiasts know it. The only VTEC in the 02+ Si is in the Intake cam: Below 2200 rpm, only one Intake valve is opening; above 2200 rpm, VTEC is engaged and both Intake valves are opening; while the whole time the exhaust valves are following only one cam profile. Basically, on the Civic Si and base RSX, there is no switch to a high-cam.


Hope I could clear things up.

The Civic Si has i-VTEC:
http://www.hondacars.com/models/specifications.asp?ModelName=Civic+Si

So does the RSX base model:
http://www.acura.com/models/model_specs_index.asp?module=rsx

...I know they do. I drive an 02 Civic Si.

I didn't say the Si has no VTEC, I said it doesn't have the VTEC that most enthusiasts are familiar with. Basically, on the Civic Si and base RSX, VTEC is there for engine-idle emissions (only running the engine on one Intake valve below 2200 rpm) and the Type-S has the high-performance VTEC that most people are talking about when they mention "VTEC."

Civic Si & base RSX: Two lobes per cylinder on Intake cam, one lob per cylinder exhaust cam. Below 2200 rpm, one Intake valve opening. Above 2200 rpm, VTEC is actuated and the rocker arms connected, now both Intake valves are opening. And on the exhaust side, two valves always opening but following one cam profile.

Type-S: Below 5800 rpm, two Intake valves following two Intake lobes (of one profile) and two exhaust valves following two exhaust lobes (of one profile); above 5800 rpm VTEC is actuated, two Intake valves following one high lift high duration profile and two exhaust valves following one high lift and high duration profile.

Civic Si Intake cam picture: http://www.hondata.com/images/k20a3cams.jpg

RSX Type-S Intake cam picture:
http://www.hondata.com/images/k20a2cams.jpg

Read the page those pictures came from, it might explain things more clearly.
http://www.hondata.com/techk20general.html

so which one is better?? vvtl-i or vtec

haha...VTEC "owns," but you could call me biased.

It don't own that good when a 180HP GTS and go toe to toe with a 200HP RSX-S.

200hp RSX-S/2767lb curb weight = power to weight ratio of .07228 hp/lb.

180hp Celica GTS/2500lb. curb weight = power to weight ratio of (not surprisingly) .072 hp/lb.

Let's keep the Type-S vs. GTS threads for the racing forum and the serious tech. discussion for this thread.

On that note, my serious answer to "which is better, VVTL-i or VTEC?" is that obviously VVTL-i is better b/c of the variable Intake cam. But if you ask whether VVTL-i is better than i-VTEC, well that's really up to the consumer. They both operate in pretty much the same way (from what I know, which, admittedly, isn't that much). The only difference I can see after taking a quick look at a VVTL-i tech article, is that the 2ZZ achieves "lift" with fewer moving parts (case in point: only two cam lobes as opposed to VTEC's three).

OUCH! lol too much for my brain...ok this is what trd told me when i asked this question

VTEC opens up the second cam at a certain rpm (say 6500)
VVTL-i and VVT-i opens up whenever the car senses you want more power at ANY rpm.

VVT-i = Variable Valve Timing - intelligence
VVTL-i = Variable Valve Timing Lift - intelligence

intelligent because it knows when you want to go faster LOL

Variable Valve Timing and Electronic Lift Control, or VTEC for short

Yes about VTEC opening up the second cam at a certain rpm.
No on all other accounts.

Here it is simplified: the VTEC changeover = "L" in VVTL-i
"i" in i-VTEC = "i" in VVTL-i

VTEC & "L" = change to a "high-cam" profile
"i" (in both cases) = continuously variable Intake cam timing.

the new vtec`s dont have a kick any more they are regulated all over the rpm so you wannt get a "lift"