Injector spray cone angle, pulse width, timing

[orlin steven jared]

Here are a few questions hopefully some of the more experienced
can help me out with..   I know some of these topics have
been discussed, but I'm not sure if any conclusions or total
agreements were reached.

I am interested in what the benefits are to a particular injection
cone angle, and to how injectors are usually aimed into the port.
Are they usually aimed at the back of the intake valve, or as close
as possible, or are they just aimed down into the flow stream?

Is there any particular benefit to using two injectors, instead of one,
at each port?

Also, has there been any general consensus or guidlines on the
optimum injector pulse width for a given application, or is this
still the fun part of tuning? :)   I guess I'm just looking for
a general starting point or feel for what I should be doing in
this area. How does the pulse width and line pressure tie in with
the closed loop operation?  Is it completely dependent (the pulse
width) on the closed loop mixture adjustments, or is it tuneable? 
If so, I imagine it is tuneable for open loop?

Finally, is there any general consensus about when to fire the
injector (in a SFI setup) in relation to when the intake valve
opens? I imagine this is probably also a trick of the trade.


Thanks,


Steve