VVT-i VS. VTEC ?...

Originally posted by AntiCt:
The differences between VVTL and dual VVT are that:
1. VVTL is cam phasing only on intake cams
2. VVTL also has cam switch on both intake and exhaust.
3. Dual VVT is cam phasing on both cams
4. Dual VVT doesn't use switchable cams

The Celica uses a system that uses engine oil pressure to drive both VVT and the "L" portion (driven seaprately). I believe the Altezza uses a set of helical gears driven from the ECU and oil pressure to phase the cams - similar to IS, GS, and LS.

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The difference I'm wondering about in my older post is not so much the mechanisms used, but the power deliverey of the two systems. So what I'm getting at in my Dual VVTL-i post is that Toyota may be waiting to employ cam phasing and switching on both intake and exhaust if it is possible. I don't think any company does this right now.

You guys are getting so good at dealing with these questions. Now all I have to do is sit back and enjoy...

Originally posted by HIBBoyScott:
The difference I'm wondering about in my older post is not so much the mechanisms used, but the power deliverey of the two systems. So what I'm getting at in my Dual VVTL-i post is that Toyota may be waiting to employ cam phasing and switching on both intake and exhaust if it is possible. I don't think any company does this right now.

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The difference is the lack of "punch" since there is no cam switching. Rather, power delivery would be linear -- but just as satisfying. I doubt Toyota would introduce a dual VVT + lift...

Originally posted by mrclam:
oh yeah, the type r engine is hand assembled too i believe

on teh system sucks thing, i didn't mean it sucks, its' a pain to stay in the powerband compared toa honda

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yup, type r engine is hand polished, I think they can polish 12 in a day or something. I agree about the celica also, the [email protected] is set too high and close to redline, 200 RPM i think, that it's hard if not near impossible to stay in the powerband. The result is a sluggish start off the line, not to great if you ask me.

Originally posted by GPR:
I agree about the celica also, the [email protected] is set too high and close to redline, 200 RPM i think, that it's hard if not near impossible to stay in the powerband. The result is a sluggish start off the line, not to great if you ask me.

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If you shift exactly at redline at 1st, it'll drop below 6000. Shift at a tad less than 8200, it'll keep above 6000. My only complaint is that you have to nail the clutch just right when shifting to 2nd, or you get a little stutter.

One thing the howstuffworks.com explanation missed to elaborate is that the I6 engine is one of four "ideal" configurations in that the instantaneous forces and moments from the reciprocating masses of the pistons are completely balanced. A 60-degree V6 is balanced in neither forces nor moments without adding the parasitic drag and rotating mass of balance shafts, but it's easier to shoehorn into any ol' engine bay. FYI, the "ideal" configurations are I6, flat-6, V8 (fully counterbalanced), and V12. Does that begin to remind of some prestigious marques?

[This message has been edited by DtEW (edited November 13, 2000).]

Originally posted by HyperMKIV:
you have to remember, the japanese usually do not come up with inovative stuff. they usually take an existing design...and they perfect it. just look at a lot of japanese products...they're usually top of the line...first rate techologically, but they didn't invent it...

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That is very true. The Japs never invented nothing. They just take whatever exists and make it a lot better. Although I guess now they are starting to invent stuff, but when you look at so many things that you relate to the best coming from a Jap company...all of it was just an improvement on something that already existed. I think the Japs are super inventive because of their environment. They live on a hazardous piece of real estate and are over crowded like mad. So they invent stuff to improve their situation. Small stereos that play as good as huge, earthquake proof buildings, etc.

going back to the honda vtec thing...honda's vtec system is the first in the world in which both the valve timing and the degree of valve lift can be changed as needed. this is an excerpt from a honda guide book.

actually, the concept was developed in some other foreign country...german perhaps??? i forget...but it still was honda that made it available in a production vehicle...

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2001 IS300 Graphite Grey
94 Supra TT/6-speed/HardTop
90 Integra
86 Corolla GTS (AE86)

At first your remark pissed me off because my parents are from Japan. But looking at this list,
http://www.lib.lsu.edu/sci/chem/patent/srs136.html

it shows the CD was the only noteworthy Japanese invention in the 19th and 20th century. I think the Japanese are perfectionists and while the term "failure is not an option" has turned into a cheesy cliche in America, I think it still holds true in some parts of Japan. The Samurai sword is considered the best crafted sword in the world. Also the old saying "necesisty is the mother of invention" is only partly true.

http://www.globalideasbank.org/BOV/BV-384.HTML

Originally posted by HIBBoyScott:
That is very true. The Japs never invented nothing. They just take whatever exists and make it a lot better. Although I guess now they are starting to invent stuff, but when you look at so many things that you relate to the best coming from a Jap company...all of it was just an improvement on something that already existed. I think the Japs are super inventive because of their environment. They live on a hazardous piece of real estate and are over crowded like mad. So they invent stuff to improve their situation. Small stereos that play as good as huge, earthquake proof buildings, etc.

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Don,
If VVTi is so great and better than VTEC, why is the IS300 so slow 0-60 (7.4-7.8sec), and why doest the Celica GTS sell at close to invoice, while the 8 year old GSR outsells it? Toyota's making nice progress in engines, but to say it's better than Honda, the premier small engine producer, is pushing it.
And please quote magazines, don't say "I read" - that's useless to us. Maybe you read it in Penthouse for all we know.

both engines are great, but the edge has to go to honda with its incredibly strong racing pedigree. honda is one of the finest engine-builders on the planet, and even die-hard toyota fans can't argue that. you can argue vtec v vvt-i all day long, but the fact remains that vtec's lineage -- straight out of f1 racing -- is tough to knock.

Well, coming from the Honda camp, i love Vtec still. I have driven my friends Celica GTS with 6spd and i just found my old b16a and current ls/vtec has more power. I must say though if any of you guys have driven a car with an ls/vtec motor or any frnakenstein setup you'd love. Awesome low end torque and even better high end power....

THANK YOU GEOFF. well spoken. and fyi, there's a difference between selling cars and knowing performance facts. why don't you read the article on edmunds of the guy who went to sell cars for ten weeks. it clearly shows that people in the car business don't give a crap about performance or the truth, but what makes the bottom line. if you ask me, it's a good thing he's not gonna make it in the car business(if that's what you raelly think.)

chiphead - i am japanese too, i don't think he meant to offend anyone...but yes, we are right tho. the japanese are not very "inventive" but at least they always take pride in their workmanship and precision.

i know a while aog someone was talking about the differences between the cl and the IS. i don't want to start a fight over this or anything, but i think that thread was talking about the fit and finish of the cars. i think the difference lies in the fact that the IS is made in japan, and the cl might be assembled in the US.

i know when my mom got her cl a few years ago, the shifter almost fell off and the exhaust shield bolts were very loose. my friend is a mechanic at the only acura dealership on oahu and he told me that the first shipment of cl's there had lots of problems...do you guys think it's due to the "american" workmaship vs. the japanese workmanship???

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2001 IS300 Graphite Grey
94 Supra TT/6-speed/HardTop
90 Integra
86 Corolla GTS (AE86)

Honda was neither the inventer, nor the first to experiment with variable valve timing.

VVTI is better than VTEC, because it's adjustment period is throughout the entire rpm band, instead of around 4500(approx), like when hondas VTEC will kick in. flexibility for optimum performance is the difference, toyota has it, honda does not.

I think even if you are talking about non-variable valve timing engines from both Toyota and Honda, Honda still has edge on engine building technology. I have to agree with Geoff here, Toyota is no where close to Honda when it comes to engine. Look at their effort in Champ Car. It took Honda a little over a year to get their first win, and Toyota? I was talking to someone who used to work with a team using Toyota motor, and he said the joke around the garage is that Toyota is there to litter the track with bolts and debris. They used all the best engineers possible and the result is first win after 5 year? I am a loyal TRD fan, but their engine building effort is just poor, very poor.
But yes, vvt-i and vvtl-i are better than VTEC.

Go to this thread for more about Toyota and Honda in racing. http://www.drizzt3117.com/ubb/Forum12/HTML/000894.html
Kota, you shouldn't be taking offense at any comment anyway. I've said this like a thousand times on this forum. I am Japanese. Even the CD wasn't invented by the Japanese alone. Sony and Philips co-developed it, I believe, as well as SACD now. Peace.