SAE paper on VVT-i

[icyjaws]

I was woundering if anyone had one or could get one. There are a couple things i'd like to know about how it work and more importantly how it chooses how far to advance the timing. Is it programed in or is it cont. adjusting with things like the knock sensor. Ok well if anyone could help i'd app it.

[vvtlikick]

This doesn't answer your question about how the ECU decides how much to advance or retard cam timing, but here's (http://www.sae.org/automag/globalview_01-00/08.htm) an article that has some cam timing info. Also here (http://www.pressroom.com.au/pressroom/sample/presskits/99celicakit.htm#17) is another article.

[icyjaws]

well that 2nd one had some int stuff in it. But like you said not really what i'm looking for :(

[Luni420]

This is just a guess but its worth a shot. Id imagine it uses all the different sensors to adjust the timing. I know it uses the knock sensor. I would imagine it uses the O2 sensor and the MAF sensor as well as some other stuff. All I know is it has a 16 degree adjustable cam and its how it gets adjusted. If Im wrong on any of this please dont hesistate to correct me.

[Celica RZ]

per TRD the VVT-i is based on a look up table much like the ignition system. However unlike the ignitions system where it'll "update" the look up table, the VVT-i does not.

[icyjaws]

cool but heres another question then.
What does it use to pick values?
Acutally i guess thats the same question i've been asking all along but noone seems to know or know where i can find out :(

[VZV21]

There isn't one at all.