Re: Injectors: P&H and SAT - Part 1

[garwillis@msn.com (Garfield Willis)]

On Tue, 23 May 2000 16:42:12 -0400, "Swayze" <kswayze@bellsouth.net>
wrote:

>many,many questions?
>is measuring the resistance enough (how do you measure henry's)?
>P&H injectors should be wired in parallel so that they drop a full 12V or
>does a resistor go in line with them?
>I'm sure more will come to mind.

WHAT!!?? You have QUESTIONS after that laborious tome? Hee hee.

You really don't need to worry about measuring inductance; the injector
mfgs have tried to keep things straight-forward and uniform, so when you
see something at an odd "impedance" like 1.7ohm injectors instead of
1.2, just figure on using a TBI level P&H driver. Large enough margins
are built into the pull-in currents that close works both here and in
horse-shoes. Anything around 2ohms and tad above you can figure will go
with TPI P&H drivers. The "high impedance" ones are also so far away
from the others that anything above say 8-10ohms you can also figure is
drivable with a SAT driver.

BUT, some REALLY hiperf guys on the bleeding edge have designed their
own injectors that require even BIGGER drivers. You'll know these by the
caption "VERY LOW IMPEDANCE". Kinsler has some listed, so does TAG in
the UK (gawd, do those guys have a nice website; tons of very complete
info: have a look at their "AppNotes" for an example of "nicely done"
at:
	www.tagelectronics.co.uk/enter.asp

Course their stuff is pricey, too. Sooprise sooprise. :)

Those impedances will be VERY low, considerably less than an ohm. IIRC,
TAG had some that were slightly over HALF an ohm (0.5ohm)! Whew.

Yes, I didn't want to interject the stuff about dropping resistors with
P&H, that's another whole canOworms. It's a kinda marginal way to do
things, and I don't know of anyone not using special drivers now,
instead of those resistors. I could be wrong, but I hope they went out
with the IGN coil ballast resistors. :)  Just a very old way of current
limiting.

But definitely P&H injectors aren't normally intended for use in series;
best to stick with the game plan, and use the right drivers.

Gar


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