View Single Post
Old 11-02-2004, 11:53 PM   #4
Moppie
Master Connector
 
Moppie's Avatar
 
Join Date: Jun 2001
Location: Auckland
Posts: 11,781
Thanks: 95
Thanked 101 Times in 80 Posts
Send a message via ICQ to Moppie Send a message via AIM to Moppie Send a message via Yahoo to Moppie
Re: V-tec vz. VVT- I (and any other form)

Prehaps you need to read the thread above again.

Then get your terminology right, its VTEC not v-tec.

There is also a differnce between just variable valve timeing, and variable valve time and adjustable lift.
Toyota have been doing Variable valve timeing since the early 90s (about 92 I think) and are very, very good at it. However its not common technology, and every mainstream manufactor now use it, often accross thier entire model range.

Adding variable lift into the system is much much harder, as you now also have to design a cylinder head, fuel system and ignition system capable of providing air, fuel and spark accross a very broud power band with very differnt conditions and requirments at high and low rpm.

Designing the mechanical parts is easy, the know how has been around for as long as the camshaft. Its making them work as a complete system in an engine that is hard, and its something that Honda with their experiance in F1 and 20 years of building production engines with VTEC are very good at.


Now understand that there is a differnce between being able to study something and having the time and resources to develop it.
Im sure Toyota went out and bought a new SiR CRX or Civic when it first went on sale in Japan, and then stripped the engine down to see how it worked. But they would still have to figure out how the ECU was designed, and work out how to replicate the technology in a way that was compatable with thier own engines, and then they would have to design a cylinder head and block combination that suit the requirments of a variable lift cam.
This would take time and money, and the people in R&D would have to justify that time and money to the people in charge of Toyota. And they would have to weigh up the demands of developing a system like Hondas VTEC with all the other R&D requirements of a world leading manufactor.


And of course if you want final proof of what is better take a new RSX Type S or Integra Type R and put it up against a new Celica and tell me which is not only faster, but which enigne has the smoother power curve, produces more hp and torque with less emissions and dosn't have a noticable change over point that the engine drops in and out of between gears.
Even the previous generation Integra GSR/VTi-R has a better engine than the one in the new Celica, and its little changed from the first mass production VTEC engine, the B16a from 1989.
__________________
Connecting the Auto Enthusiasts
Moppie is offline   Reply With Quote