Commercial systems

[Johnny]

Bill wrote:
> 
> Although I am keenly interested in diy_efi, the schedule of my current
> project requires that I purchase a commercial system.  I seems that the big
> players are Haltech, DFI, and Electromotive.  Does anybody have any
> experience with any of these organizations?  I've spoken with them over the
> phone and although all seem to be knowledgable, have imparted more than a
> little confusion.  I'm told by a competitor of Haltech, for example, that
> Haltech is a "bank-fired" system.....meaning that after the calculations are
> complete, all 4 injectors on 1 side of a V-8 are fired simultaneously, then
> the sequence repeats for the other side, and so on.   Has anyone ever heard
> of such a system?
> 
> I'm also wondering about how the effect of manifold vacuum or pressure
> affects the rate of fuel delivery, all other factors being equal.  For
> example, if a given pulse width results in 10 #/hr of fuel with a given fuel
> rail pressure, does that mean "on the bench"?  What happens when the same
> injector is spraying into a 10" or 20" Hg vacuum?  Does that tend to suck
> extra fuel.  Or what happens when the boost is run up to 20 psig?  Clearly,
> its the pressure differential that is at issue here.  And nobody seems to be
> talking about modulating fuel rail pressure in response to manifold
> conditions in an attempt to keep the pressure differential constant.  Is
> this really an issue, or am I making this more complex than it has to be?
> 
> Lastly, does anyone know of a commercial system that is soon to be retired
> in favor of a later model?  Or does anyone have a funtional DIY_EFI for sale
> at this time?  My parameters are as follows:
> 
>       Small block Chevrolet motor (377 cu in) in flat-bottom V-drive boat
>        (2) AiResearch TO-4 turbos
>        Powerglide
>        Crank-driven ignition
>        Gasoline fuel with methanol enrichment at higher power levels (>5
> psig boost)
>        6000 RPM maximum
> 
> Thanks for any and all information.
> 
> 
>   William Sarkozy
> 
>    Kalamazoo, MI

Want to race when you are done? I have a Steve Jones boat with FE Ford, 
2 Holley Projections on a Dove tunnel ram feeding a set of Dove medium 
riser aluminum heads. Just got it all done. I went with the Projection 
units so I wouldn't have to build an intake and everything else for this 
one. Convenient to just throw those suckers on a conventional tunnel 
ram. For your app though, with the SBC and all, I would go with the 
Haltech unit and probably an Accel intake and air door. The reason for 
the Haltech recomendation is that it seems to be the best suited for a 
boost/methanol or nitrous injection setup.

The other thing you might consider is trying Accel's newest ECU, the 
Sequential Spark/Fuel Management (SSFM) unit. This baby will do spark 
and fuel on a per cylinder basis and allows 3 separate nitrous stages 
with independent fuel and spark control of each, which you can use for 
your methanol enrichment at various boost levels. They will sell you a 
complete package including all the hardware, harness, ECU, and 
programming software. Get your Visa out and prepare to max it though.

You can call there EMS division direct by calling 216-398-8300 and ask 
for extension 488 Mark Hammel.

BTW, the unit is compatible with GM's GM-ZR-1 DI if you can find one in 
a junk yard somewhere, or if you wanted to really get trick, you could 
call Firepower and get a dumb box and 4 of there awesome coils.

When you have it all together, drop me some E-mail and we will go run 
'em. There aren't two many of us Flat V-drive guys left alive, or the 
boats either for that matter.

-j-