IS300GTE wrote:
toyota does use that for feedback and does go to open loop at WOT, but thinking that the car was at WOT, when it really wasn't would only cause it to run overly rich, which can drown out low end torque, in probably take away power. do you think?
Sure seems like that would be the case if they advance it too early. I suspect/hope that they actually just apply a gain function to the signal and don't just toggle between closed and wide open. It could be made even worse if this signal is an input to the valve/flapper that shortens the intake runners. That type of system is typically controlled by RPM (or I think I read that Toyota uses manifold vacuum) so it might not be a factor there.
What confuses me most is how this would work at all in a throttle by wire car. If there is closed loop control between calculated throttle position (presumably a function of pedal position, speed when cruise control enabled and input from the trac control) and measured position as indicated by the TPS I just don't see how this could possibly work. If it isn't really closed loop and the TPS is just used for rough position (idle/closed, tip in, open, WOT) and they get it into WOT engine management mode at part throttle (assuming you were not on your way to WOT anyway in which case you get this advantage for fractions of a second) then there may actually be a little bit there. WOW - now that is a
THIN argument. I am still firmly in the highly skeptical camp on this one.
While we are on this topic - can anyone give an authoritative review of how the IS300 throttle-by-wire works? Do they use the throttle plate instead of an idle air bypass valve since they 'appear' to have control over the throttle plate position? Or do they only have the ability to damp throttle input? Is cruise control integrated into the system or is it stand alone?
Thanks
Terry