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Re: P&H Injector Interface



Some thought starters.........


1)  How about a module which would handle either SEFI or BATCH, at the whim
of either a set of DIP switches or a set of software switches?
2)  How about configurability in terms of "X" inputs versus "Y" outputs (for
grouping), to accommodate both the true versions of above and the pseudo
versions of same which are typical of some of the aftermarket EFI vendors?
3)  How about +/- BPW correction adjustments, per injector output signal, as
found in the ACCEL "VIC" product (a comparable external 2-8 signal driver
batch box)?
4)  Definitely design around 8 cylinders.  One elegant, but generic, design
should cover everyone's needs whilst keeping design/development costs
reasonable and leaving the door open for future project growth.
5)  Design for the worst case drivers.  Injectors with lesser demand can
still be driven via the greater driver, and the cost differential should be
negligible.  It should be possible to mode the final drivers to either P&H
mode, or SATURATED mode, at the whim of a switch controlling the circuitry?
6)  House the gizmoid in a reasonably weatherproof box.
7)  Shield the box chassis against underhood electrical noise.
8)  Huge heat sinks for durability (or marketing - depending upon your slant
in this arena).


I think that the "box" you describe is one of the most important (missing)
elements in a DIY'ers tool box.  The easier it is to use an "abc"
controller/software package together with "xyz" injectors, the better.
Have seen too many "specialty"  boxes over the years which attempt to cater
to too small a market segment.  As a result they do not flourish.



Walt.






>>> If a module was made that covered
>>> just 6 & 8-cyl cases, would that cover just about everybody in the SEFI
>>> camp? Lastly, would anyone mind paying the additional small incremental
>>> cost to an 8-cyl interface module, even if they only needed a 6 at the
>>> time (say for the sake of conversation the *difference* was less than
>>> $40)? Would someone rather have the chance to use the same interface
>>> module later on an 8 they might run across, and be willing to pay for an
>>> 8, especially if only an 8-injector module was made? Or would that piss
>>> the 6-cyl guys off?
>
>Anyone else wanna take a shot at this question? Remember, this only has
>to do with the Sequential P&H Interface module issue. Come on, there's
>gotta be at least one guy contemplating P&Hs in a sequential ECM onlist
>that has an opinion. Then again, maybe not.
>
>BTW, here's the present thot on the Batch side of things: basically, we
>wanna drive two wires, each with 2, 3, or 4 P&H TPIs. The issue is that
>the peak current and hold current levels for each combo are different.
>I'd like to avoid a bunch of different models, so the thot is just to
>make the internal drivers big enough for the worst case, and then you
>*switch-select* how many P&Hs you're intending the interface should
>drive. This means a bit of overkill for the lower end of the driving
>requirements (if you only wanted to drive 2 or 3 per wire), but I don't
>think the cost differential is worth designing several different models.
>
>So, what I'm thinking at this point is one switch-selectable interface
>module for Batch, which I think/hope covers all the GM cases, and one
>SEFI interface module which contains enough drivers for 8 separate P&H
>injectors (of the 2.4ohm 4mH variety). If you need only 6, well I guess
>you have a couple spares. :)
>
>In the case of the Batch module, I think a hard break into the harness
>wire near the ECM is the only acceptable/reliable waytogo. Bruce's
>suggestion to provide all the connectors, etc. and allow fallback to the
>original wiring, would be the plan. In the case of the Sequential, if
>it's possible to manage a simple pin-swap with a cheap pin extraction
>tool and connectors supplied, that would be the plan. Either way would
>be completely reversable, electrically speaking.
>
>If ya wanna influence this, ya gotta gimme yer feedback.
>
>Gar


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