Re: [AMC-List] Fuel Injecting the big Dogs

["Swygert, Francis G MSgt 436 CES/CECM" <Francis.Swygert3@xxxxxxxxxxxx>]

Armand, everyone I've ever talked to about the Holley EFI system has
said "spend the money for the closed loop option!" (back when it was an
add-on, which was after the first kit came out). The first Holley system
was really made for the drag strip, not street use. You had a control
box and had to set everything! The only racer I ever talked to that used
it successfully and really liked it kept a chart with key measurements
(temp, humidity, altitude, 60' time, 1/4 mile time) for each track, and
what settings were used. He would then take those readings before a run
and make the proper settings. Car was pretty consistent after a couple
years running. Every time he made a change (cam, jets, whatever) he had
to make an estimate of the settings then start over keeping records. He
got good with it -- after a half dozen runs it would be pretty much
dialed in. To get the best results on a street vehicle you had to make
minor adjustments all day. A carb was better! He never tried it on the
street, realizing the amount of adjusting that would be needed to make
it superior to a good carb. The closed loop kit made it streetable, but
it was still hard to adjust until a computerized tuning system was
introduced. The old ones had four or five dials that were adjusted
manually, no computer interface that I recall. 

The Edelbrock system is great, but there's something they don't tell you
in most of the literature -- you need a PROM programmed for the
base-line. The Edel EFI is made by an OEM supplier for Edelbrock. When
you buy it you get a card to fill out with your engine parameters. The
company then burns a PROM and sends it to you. THEN you can program the
computer -- or rather fine tune your engine. The computer still only has
so much +/- adjustment from the base-line parameters. To me this isn't a
truly programmable system. If you swap cams you will most likely have to
have another PROM burned, unless the difference in the previous cam is
relatively minor. If you like to tinker with the engine and try
different things you'll quickly run out of adjustment range. If you have
your engine about where you want it and don't plan on making a lot of
changes, this is great! Otherwise you need a truly user programmable
system.

As far as user programmable and affordable systems go, there are two
that I know of. Both require a little work on the user's part. They are
just computer and wiring systems, you have to adapt/furnish intake,
wiring connectors, and sensors. 

The first is the MegaSquirt (http://www.bgsoflex.com/megasquirt.html).
Depending on your level of electronics skill, you can build the thing
from scratch, a bare circuit board and parts kit, or buy complete from
several different vendors who will guarantee them. Glen Hoag is a dealer
for ready to go controllers (a list member -- www.glensgarage.com -- for
an article on one of his units see
http://www.olenik.com/tvr/tvr.pl?page=fuelsystem). These have been used
on everything from lawn mower engines to turbo V-8s, and I think on a
couple Jag V-12s. 

The most complete unit that has been around longer is from Simple
Digital Systems (www.sdsefi.com). This comes with a hand held
programmer. It's made in Canada and has been around since 1993. Costs
more than the MegaSquirt, but it's more sophisticated too. It's even
been used on aircraft (but isn't certified -- home builts and owner
conversions)! I've watched this one develop for a while now, and if I
were going to use a ready made aftermarket system this would be it. I
don't think anything else is as flexible at the price. There are similar
systems out there, but all are more expensive and/or limited.

The new Racetek system has the advantage of being all but bolt-on and
drive. You still have to connect a computer to put in the base-line
info. But this is about as easy as it gets -- bolt-on, plug into your
desk-top computer, answer a questionnaire type program, install ECU,
then drive!! Not a lot of tinkering -- the system adjusts itself as you
drive. 

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