injector transit times and flowrates

[Scott M.]

Andris,

The opening and closing times are dependent on the type of
injector and driver circuitry used. The low resistance
injectors (1-4ohm) that use the "Peak and Hold"  drivers
react faster. The high resistance (12-16 ohm) injectors
that use the typical saturated transistor switch for
operation are slower. 

I don't have the specific times for the "Bosch" injector
you mentioned but the SAE standard J1832 Nov 89 lists some
typical opening and closing times for both Peak and Hold
injectors  and for saturated switch injectors. Typical
times to fully open Peak and Hold type are shown at ~1.4ms,
(it takes about 0.8ms for the pintal to begin moving),
fully closed time ~0.5ms. The saturated switch injector
opening time ~2.1ms, closing time ~1.1ms. A 4ms pulse was
applied to both injector drivers.

Check  this paper for more details. This was listed in the
1994 SAE Handbook 2 page 26.263    Your mileage may
vary......

HTH
Scott M.

.----------
> From: Andris Skulte <askulte at emerald.tufts.edu>
> To: DIY_EFI <diy_efi at coulomb.eng.ohio-state.edu>
> Subject: injector transit times and flowrates
> Date: Monday, November 10, 1997 1:46 PM
> 
> How long does it take for a Bosch injector to open and
close? I'm trying
> to figure out the exact fuel delivered, and have the
injector pulse
> widths from a GM ECM. I'm adding larger injects, and
would like to
> figure out how much extra fuel they will add at the
shortest possible
> pulsewidth (provided by you fine folks!) For the larger
capacity
> injectors, is the hole the pintle slides in just larger,
or is the whole
> pintle shuttle larger as well? I'm going from Rochester
19# injectors to
> Bosch SVO 36# injectors in anticipation of the twin
turbos. Thanks for
> the help :)
> 
> -- 
> ********************Skulte Performance
Designs************************
> Andris Skulte   askulte at tufts.edu  
http://www.eecs.tufts.edu/~askulte
> 89 IROC M5 305 TPI     13.5 at 104.1   320 hp / 470 ft lbs
>  
> Leave late, drive faster, still get there first. ;)