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VTEC vs VVVL-i


SolReaver
04-28-2001, 01:11 PM
Aren't they the same? If not who is better?

SolReaver
04-28-2001, 01:12 PM
Oops one too many V :D

enzo@af
04-28-2001, 01:38 PM
I've heard that the VVTL-i is better. People say because it has "lift intelligence"

gang$tarr
04-29-2001, 01:01 AM
well vtec is kinda an old technology, soon there will be vtec-i..... juss like VVTL... into VVTL-i
it's vtec with inteligence, or whatever
it'll be way better than VVTL-i :frog:

enzo@af
04-29-2001, 03:39 PM
Of course, doesn't Porsche use a continuously variable VTEC-like system? That would kick either of those's arses.

Jay!
04-30-2001, 12:37 AM
is "more advanced."

VTEC has two sets of lobes for each valve, and the valve levers would switch over at the predetermined threshold. (FYI: the NSX engine had three cam positions.)

VVTL-i is "continuously variable," meaning that it doesn't choose between two settings, but rather it can move to any setting in a range. I'm sure that the computer choreographing the changes is super sophisticated.

I always heard that turbo-charging a VTEC engine was troublesome. I wonder if the VVTL-i technology will be more adaptive...

gang$tarr
04-30-2001, 05:54 PM
yeah silver but the VTEC-i will kick the vvtl-i :rocket:

Jay!
05-02-2001, 03:34 AM
I guess we'll see. Anybody know what H-car is planned to get it first?

gang$tarr
05-05-2001, 01:19 AM
prob prelude or s2000

Jay!
05-05-2001, 01:25 AM
Actually, I'll put money on the RSX having the first to hit the street. AutoWeek printed a picture of it this week; it's the first picture I've seen of an i-VTEC engine in a car.

SolReaver
05-05-2001, 09:16 AM
How about the new Civic hatchback with a new 170hp engine. It has i-VTEC.

Jay!
05-08-2001, 05:08 AM
I think I heard that, too. But it won't be here until late next year, is that right?

Doh! Where'd I read that? :rolleyes:

texan
05-08-2001, 05:53 PM
Silver S2000- VVTLi does use multiple camshaft lobes, and is very similar to Honda's VTEC (which uses 3 cam lobes to every 2 valves, not 4). It's biggest advantage (aside from changes in cam phasing through electronically adjustable cam gears) is not having a third rocker arm and third lobe for every two valves, which saves weight in the valvetrain. Of course this is also it's biggest disadvantge to VTEC, since only having one lobe active per set of intake or exhaust valves means it's not able to stagger valve lift and duration between the valves at lower RPM like VTEC setups do (which prevents the easy introduction of swirl and tumble to the mixture).

If you ask which is tuned better though, all VTEC motors are currently setup better than Toyota's Celica GTS motor. The Celica's VVTLi motor has a hiccup in the power curve at 6000 RPM (where the big cam kicks in), and doesn't possess enough RPM potential to keep you on the big cam during upshifts. Which partially counteracts the whole point of having variable valve lift and duration in the first place, and I think was a cost cutting measure on Toyota's part. If you extened the redline another 500-600 RPM, you could stay on the big cam once you reached it in first gear, and the car would definitely better the B18C1 in power output and accelerative ability.

gang$tarr- The Prelude is gone, no longer produced, the damn dirty RSX Type S is both the Integra and Prelude's replacement.


enzo@af- Porsche's Variocam Plus setup is nice, but currently only used on the intake side of the motor (if memory serves me correctly). Variocam Plus has 3 cam lobes per valve, and uses an adjustable hydrolic lifter to facilitate different cam lobes being in control of the valve. It is two stage (just like the others), very compact and simple in actuation. Regular Variocam is just changable cam phasing, and is no big deal.

JD@af
05-08-2001, 06:02 PM
(applause for texan)

I didn't realize that VVTL-i discouraged swirl through unified cam lobes below the VVTL-i range.

Inspiring excellence as always.

VTEC V6
05-30-2001, 12:13 AM
i got a video of hte new porshe 911 turbo and they talk about the engine and all sayin it gots something similar to honda's VTEC system but it can actuate anytime not like honda's fixed timing as in 5500rpm on a civic

JD@af
05-30-2001, 07:48 AM
I've read about the Porsche variable valve timing as well. I forget the specfic details of the mechanics of the system, but indeed it engages a mechanism that increases duration and lift of the cam profile at certain rpms. I was not aware that this system was able to be initiated without a necessary rpm range; however, I believe that Honda's VTEC system can work in this way as well, since ths system is governed in its operation by four controlling factors, including rpm and throttle position.

texan
05-30-2001, 05:29 PM
read the bottom of this page guys...
http://www.fortunecity.com/silverstone/lancia/58/technical_school/engine/vvt_31.htm

It explains how the Variocam Plus system is a two stage setup when it comes to lift and duration levels, while the cam phasing portion is continous. It's damn near identical to VTEC-i, except that the engagement mechanism is significantly more compact and ingenius (it had better be, since it's ten years newer in design).

JD@af
05-30-2001, 05:40 PM
Great, I'll check out the link you supplied.

Much obliged, sir ;)

gang$tarr
05-30-2001, 06:25 PM
yeah i know the rsx is gunna replace the prelude & integra, i posted that a long time ago, before i knew that

the civic hatchback isn't gunna have vtec, the civic Type R will

Moppie
06-30-2001, 04:40 AM
Originally posted by VTEC V6
.........but it can actuate anytime not like honda's fixed timing as in 5500rpm on a civic

I believe only the SOHC VTEC's are restricted to a fixed crossover point in the RPM band. My DOHC B16a however is able to change at anywhere from 4,800rpm to 5,300rpm depending on road speed, engine speed and throttle position. Very handy if you dont want a flat spot when driving hard out of a corner, or when crusing at highish speed while still getting the best available economy.
:cool:


I believe Ferrai has a simlar system, that uses a sloped lobe, from high lift to low lift its a smoth transition and the camis slid sideways accross the top of the valve. http://www.howstuffworks.com/camshaft3.htm

JD@af
07-02-2001, 03:46 AM
WOW! Thanks for the link! I was under the impression that Ferrari did not use variable valve timing to make their high horsepower, high rom screaming engines. I guess I was misinformed.....

Jay!
07-02-2001, 04:08 AM
Yeah, that www.howstuffworks.com site is great!!! I read stuff on there for an hour, and put it in my IEFavorites so I'll remember to go back later.

Thanks for posting it. :D

Dude, you're really cleaning up around here. (No pun intended.)

Moppie
07-02-2001, 10:34 PM
Originally posted by JD@af
WOW! Thanks for the link! I was under the impression that Ferrari did not use variable valve timing to make their high horsepower, high rom screaming engines. I guess I was misinformed.....

It was shown to me by someone else in another (lesser) forum. I certainly didnt know about it either, looks like Ferrari were keeping it pretty quite, probobly didnt want people thinking they were no better than a Honda! :silly2:


Silver S2000
Thanks, (and there is some meaning in that pun) but Look to Texan and some of the others (I dont know many of you yet) for the real Tech advice. I only know the basics, and what Iv learnt from others.

:cool:

evil_elmo
07-05-2001, 06:40 AM
what cars does the VVTL-i engine come in?

Jay!
07-05-2001, 07:02 AM
I know it's on the Celica, the ECHO, and almost all the Lexuses. Maybe the MR2 Spyder, not sure... what else?

Moppie
07-05-2001, 11:16 PM
Originally posted by Silver S2000
I know it's on the Celica, the ECHO, and almost all the Lexuses. Maybe the MR2 Spyder, not sure... what else?

The Celica is the only model to have the VVTL which is the two cam lobes, all the others only have the vraible cam timing, which is something Toyota have been playing with since '91 with a 20V version of the old 4agze. There was talk of a super fast VVTL-i powered MRS but it never seems to have happened. I think Toyota leaned on the side of caution, 180hp in a such a light little car, would be deadly. However since it uses the same basic engine as the Celica, an engine swap is quite feasible.

Integra-F20C
11-02-2001, 07:13 AM
hey hey hey!..look who's back in town!..:D

well anyway guys, form my experice of test drigin a stock JDM Integra SiR and a stock Celica SS2...which has same enggine but more hp thenn the usdm GTS..

let me tell u what..at first when i drove it..i thought...that celica should be much torquey then the B18C teg at low rpm...so i stepped on it..but now...it was abt the same as a B18C jdm Teg..so i waited until it pulled over 5500rpm..ok..u can't feel no explosiveness from that car stock for stock..all i can say is..whatever that VVTi-L says it should do, it's nto doing so, it accelerates like a freaking pregnant woman at high rpm's not as explosive as honda if even comapred to a 1.6L B16A...and still restsless at low rpm's.

so at the end, I'd say, come'on TOYOTA!..u can't even god damn beat a B18C Teg made 7-8 years back in technology and perfroamnce!..
and then...well..after i finished test driving, I opened the hood, and all i found out was.."SH*T!..how in da hell can i mod this thing?!"
the engine bay was smaller and tighter then a fat woman with extra small shirt, and even changing the intake into a cone was pretty hard i'd say..and as for headers...many of u know..that just changing headers for celica is a damn big job, so yea..geez..7-8 years newer technology then the B18C teg, and it still performance wise, can't beat sh*t..but the onyl good thing i can say is, it's prettty comfortable inside...but not a car that u can make it fast, easily..gotta have lot's a cash!.:D

but yea..just my 0.2 cents..

F20C
11-02-2001, 12:49 PM
Hey Integra how did you manage to put F20C into your car?

Integra-F20C
11-02-2001, 06:36 PM
Originally posted by F20C
Hey Integra how did you manage to put F20C into your car?

haha..sorry...the answer to ur question is..I can't and i don't have that much $$$..and even if i did..i won't bother tryign to put a F20C in my car..haha..it's just a nick name i used 2-3 years ago so yea...that time i was stupid and thought i wanted to fit one but as time passed i found out the whole engine spinned the other way round which therefore, if i wanted to fit it, my car could only have one gear going forward and 5 gear going back..:D

so uhh..yea....:(

Jay!
11-02-2001, 06:38 PM
Originally posted by Integra-F20C
...my car could only have one gear going forward and 5 gear going back..:D

so uhh..yea....:( Hahahaha!!! :lol2: :cwn27: :hehehe:

Integra-F20C
11-02-2001, 07:35 PM
Originally posted by jay@af
Hahahaha!!! :lol2: :cwn27: :hehehe:

imagine stopping at the lights and a mustang revs at ya...and u rev back the mighty F20C motor in ya Teg..and then light goes green drop clutch...first gear..and..:bloated:

:D

hmm/..gives me a new idea..now i can go drifing in reverse.!..:D

F20C
11-02-2001, 09:01 PM
Now it's fun to drive backwards and going 55mph. haha

boots
04-14-2004, 11:13 AM
porsche variocam still is the best because it works all the time it dosent have a fix time it give the car the power all the time. what do people expect its german engeniered

YOUNGSTER
04-14-2004, 05:52 PM
nissan has something simaliar i forget what its called like vvcc or ccv i dont member and bmw and vanos

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