Injector timing qns.

[Jonathan R. Lusky]

Craig Pugsley writes:
> 
> That's basically what I was wanting to know. The main aim at lower RPM
> is to get more torque (Mazda rotary = poor low down torque)
 
Ugh, how many times are you planning to fire the injector each crank
revolution?

> Hmm... I kind of mis-worded the question. What I'd like to know is
> how linear the fuel flow vs injector time is (For a given
> fuel pressure) when injector time is small, and if compensation for
> this deviation is nessecary.
 
It depends on the injectors, your fuel pressure, and how low you go.
On GM speed density systems this is compensated for by fudging the
volumetric efficiency tables....  sorta beat it to fit kinda thing.
Aftermarket speed density systems are similar, except that they generally
look up pulse width directly from (RPM,MAP) instead of pretending to
go through a VE step.  Bottom line: compensation is done in the calibration,
the algorithms for speed density assume the injectors are linear.


-- 
Jonathan R. Lusky                       lusky at knuth.mtsu.edu
http://www.edge.net/erc/lusky.html      (615) 455-9915
------------------------------------   ------------------------------
68 Camaro Convertible - 350 / TH350 \_/ 80 Toyota Celica - 20R / 5spd