There was a 1.8T conversion one of the lads did a few years back that I thought was (at least) closing the throttle plate to enrichen the mixture but a dodgy oil pickup destroyed it before I had time to go into details. Felt like power loss in mid range before it picked back up, consistent with air/fuel/rpm if I remember right. There does tend to be load limitations and technically the drivers request is as per dk opening for charge in many respects.
However, with the sheer depth of rc/rl charge details in computations;
https://app.box.com/s/lr5yx98l0j8az3xb1d94mgik2t7s2p6thttps://app.box.com/s/mgalngtwdggjwj9ciy08yachlvtz4zvwCoupled with the patent statements like;
"The pivotable throttle valve is fastened to a shaft BE, which is operated by a control device for adjusting the shaft and thus also of the throttle valve at a given angle, and so the supply to the motor through the channel with a predetermined amount of air or Ge mixed for allows different operating conditions of the engine."
http://www.google.com.pg/patents/DE4135806A1?cl=enhttp://www.google.com.pg/patents/DE4306607A1?cl=enThen I always assumed that the ecu would lessen the plate angle for lean running before anything else as it stands to reason.
You have a detailed mass/energy relationship in Physics so say the ecu took a different route and extended the opening time of the injectors so that more fuel is released. Firstly, there's the possibility of already maxxing duty cycle so no more fuel, but if not, what happens with this extra opening time/fuel? Well, one thing is the spark timing would or possibly could be way out, especially seeing as you are likely running lean at higher loads/rpm's, so you've less time to mess up really! You have a "flight time" of the droplet of fuel so how does this change? I doubt my svelte 125kg frame can keep up with Usain Bolt in the 100m so there is a mass/energy/(relative) time relationship to think about and in this case, how long does the droplet take to get where it's going if the ecu increases timing and therefore mass? (Also short runners/injector placement changes etc of course in aftermarket mods).
So if the ecu is piddling about trying to add fuel that may or may not be there with these changes, plus the wall wetting/flight times/spark timing/energy etc - then will it need to adapt the spark timing too and lots of other maps? If at high rpm's then surely just decreasing actual versus drivers load is the quickest way to enrichen the mixture so either holding the throttle plate at it's current angle or closing it a touch would surely be the better way?
Given that I always assumed yes, it does that as it would be easiest and most likely safest way of doing it, a bit like completely cutting throttle if all else fails in it's computations, it's something the ecu can control easily!
p.s. I know you're not a noob and likely know these things, but I am trying to put links I can find easier up in places!
