VVT-i VS. VTEC ?...

People always miss the point about VTEC, you're not only gaining when it's on-cam above 5000 rpm (or whatever), you also gain at low rpms because you're running a different timing than you'd be forced to run without VTEC. So it improves power(torque) at all rpms, not just high. Honda has been at this game longer, and has its Formula 1 manufacturer's championships to back up it's pedigree. The engine in the Integra Type R is a superior engine to the Celica GTS, I doubt anyone would argue otherwise. It's more powerful, better sounding, and smoother at high rpms.

Originally posted by DonCorleone:
basically Toyota's VVTI (not VVTL-I as stated earlier, my bad) is better than Honda's Vtec because you don't have to wait for it to kick in (as in the case of the Vtec)...but install a Vtec controller and thats another story.



[This message has been edited by ckolsen (edited November 10, 2000).]

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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.

When Toyota sells an engine that makes 240 hp out of 2.0L, then I'll agree. How about 260 hp out of that CL 3.0L V6? When I test drove the Celica GT-S, the sound coming out of that engine at 7500 rpm made me cringe - that motor didn't sound happy - nothing like the sweet sounds from a VTEC motor at 8000 rpm.

Originally posted by Daniel:
But yes, vvt-i and vvtl-i are better than VTEC.[/B]

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Ok, point taken. While the Celica engine gets raspy at high revs, the IS300 engine is silky smooth at redline. They need a lighter aluminum block for 50/50 weight balance, and a 5 speed manual, and the IS300 would be perfect. They need to do it quickly too, before Honda gets their act together and builds their RWD sedan, or BMW fixes the 3 series steering.

Originally posted by Daniel:
What I meant is that the vvti vvtl-i technology is better, more advance then vtec, although this does not mean Toyota's engine is going to outperform a Honda vtec engine. You got to agree that vtec is old and is not a very efficient method comparing to vvti, vvtl-i, double-vanos, and other continuous valve timing system, but your example is perfect at showing how good Honda is when it comes to building engine. They can use an old technology and build one of the best, if not the best, engine in the market right now. I just cannot imagine what will happen to S2000 engine if Honda implement something similar to vvtl-i. 280hp or more on a 2-liter?
Now Toyota should buy out Yamaha, then they will have a good chance competing with Honda.

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I'm speaking very specifically - the Celica engine sounds like it's straining at high rpm, while the GSR/Type R/Civic Si engines sound like Formula car engines at 8000 rpm. I noticed this difference, as did many car magazines. Some people may like that F1 sound, some don't - like women.

Originally posted by HIBBoyScott:
Your argument about engine sound holds no water. The old school big V8s sound better than the engines today...that doesn't mean they were better, does it? Even the current big engines in domestics sound better than the imports. I still don't want a domestic though.

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I have a degree in Japanese studies (and mechanical engineering), I work for a Japanese company, and I'm part Japanese, so my take on 'inventing' is this:
The Japanese are not strong on basic research, they put a much stronger emphasis on applied research and development, primarily product development. So it depends on how you define inventions, the Japanese 'invent' a lot of things, but many of them are refinements of existing technologies - but no less impressive 'inventions'. Japan's education system doesn't put an emphasis on original ideas the way the US system does - at least the schools where kids can actually read and aren't killing each other.
BTW, my grandfather created the first artificial snow crystal, and he was Japanese.

The ideal air/fuel mixture ratio varies according to rpm, so having just one cam setting would not be optimal for either low or high rpms. Or some **** like that.

Originally posted by West:
Wow, you guy seem to really know what you're talking about it... I really learned a lot. Seems that everybody brings a new angle which makes the whole issue more clear.

I have a few questions for you though:

So this variable valve timing gizmo varies when and how far the valves open, right?
But why do you need to do that? Why not just take the most "hot" (I think that's the term) cam profile and put it on the engine??
Do you loose low end torque?? Why?

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Seems like you two are saying the same thing, but it's hard to tell. My point is this, having driven (many times) an Integra LS and GSR, the VTEC version of the 1.8L definitely has more power below 4500 rpm than the non-VTEC 1.8L. (I know the gearing in the 2 cars is slightly different, but I've driven them enough to tell the difference).
This low-rpm difference is probably because Honda can optimize the cam profiles for low rpms better in the VTEC version, while the non-VTEC motor must make do with one setup across the entire rpm range. Make sense?

I think I speak for the majority when I say:
"This thread should die."