SDS EFI - Unconvinced

["Vee Dubb" <Scirious@hotmail.com>]

Has anyone tried both an SDS system and one of the PC programmables?  I've
only had experience with Haltech's PC programmable F9 and F9-A systems and
I've never used SDS.  I've also used MSD's digital ignition system, which I
was very pleased with.  I'll just talk about the fuel side of things mostly,
but the same arguments apply to both fuel and ignition, or to combined
systems like the SDS EC-3, or the Haltech E-6, or elecromotive or motech
stuff too, I think.  So I'm not trying to say Haltech is definately the
world's greatest, but it's what I can compare to, and I think its
representative of the PC programmable croud.  For starters, contrary to what
the SDS site claims, Haltech's systems are cheaper than theirs.  Some other
systems are a few hundred dollars more than SDS's.  As far as the expense of
the computer goes, you only need a dinky computer to program this stuff
(like a 486 is massive overkill), and you only need a laptop if you want to
do datalogging on the road (which sounds like fun, but it's not necessary).
Last car I worked on we used a laptop, but we just left it sitting on a desk
with a 10' cable going to the car.  Ran it up and down the street and came
back for rough tuning, then sat next to it on a dyno for the fine tuning
(dyno's are optional in this game, by the way, but they are convenient).
It's not like you are going to be programming it while you are driving.  So
if you only have a desktop, you might have to drag it (or an old spare
computer) out to the garage.  Besides, antique laptops are only a couple of
hundred anyway.  The main motivations listed on the SDS site include the
following:

1)  List of basic capabilities - seems you can pretty much compare these for
yourself, but I think its safe to say that you can make an engine run well
if you know what you are doing with any of these systems.  Main difference
here seems to be 250rpm increments instead of Haltech's 500rpm, but the
points (for Haltech, and I'd assume for SDS as well) are interpolated
linearly, so I don't see much advantage there.  Because of the high rpm
limit (above 10,500rpm) on the car's I have worked on the map is broken down
into 1000rpm increments on a Haltech - and the map still looks pretty darn
flat and the points are still interpolated.  I think the extra precision
doesn't help much, except maybe at idle, but then there is a separate map
for that anyway.

2)  Quality - did you ever see anyone say that their components were
anything but the industry's best?  Might be true, but who knows?  Anyone
have any real experience on this issue?  I'm sure that mixing and matching
components

3)  PC anxiety - come on folks.  For starters, if you don't understand EFI
(not that I'm an expert...) then you aren't going to be able to do any of
this, so the hard part doesn't change.  We all figured out e-mail and can
probably
figure out how to install a program on our PC.  The instruction manual for
Haltech (again, this is probably true of other PC systems, but I only have
experience with Haltech) gives you a step-by-step run down of how to program
it, what each feature does, etc.  The whole thing is pretty much like
following a cookbook, and is certainly explained better than a Bentley
manual.  Actually, the first time I used on I had never even seen the manual
(just inherited the car from the group who made it), and we were still able
to make improvements and understand what was going on.  All I can really say
is that it seemed awfully simple to do it on a
PC.  SDS's scare tactics here are pretty juvenile.

    ONE nice thing about using the PC is the amount of information you can
see at one time and its graphical presentation. For example, instead of
programming each point of the temperature compensation graph one-by-one, on
a PC you see the whole graph in front of you.  It's a bar graph, and by
highlighting each bar you can increase or decrease it by one increment or
ten increments, or type in the value you want (the advantage to having 104
keys instead of 7).  Other info, like temps, rpms, throttle position, etc.
are displayed in real time at the bottom of the screen if you ever need
them.  You can do things like set two points on any graph and
linearize everything in between, or change a range, or even every map point
by some percentage.  Doesn't sound like SDS could let you do this.  Anyone
know if it someohw can?  Same goes for the main fuel map. The 3-D map (fuel
amount vs. throttle position (or MAP if you choose) vs. rpm) is displayed as
2-D maps (fuel amount vs. throttle position) for each rpm range.  There is a
pointer to show you which point on the map is being used by the ECU at that
instant, and a jump feature that will take you to the part of the map that
is being used if you aren't already there.  Don't get me wrong - DOS was
great and all, but I wouldn't want to draw a map point-by-point with it when
a GUI is available.  How many times would you back-track, wondering, "now
what was the last value I put in?"

    Second nice thing is the big SAVE-your-ass feature (pardone my
Francais).  You can save the entire fuel map as well as all auxilliary maps
(closed throttle map, temperature map) and put it on a disk.  Want to try
out some new cams?  Feel free to change whatever parameters you want.  If it
works, save it.  Save as many versions as you like!  Then this time next
year if you decide you really liked the old setup, then just load the old
map off of your hard drive.  That way if you start tinkering with stuff and
it ends up FUBAR'ed, you just go back to your favorite map and hit the road.
Trust me on this one.  Even when you are trying to just make a tiny little
improvement somewhere, eventually, at least once,  you end up wishing you
could return
everything to the way it was.  With a PC system this is no problem.  Imagine
spending a year writing a thesis and having only one copy!  Would you buy a
word processor that only showed you one word at a time and didn't let you
have a backup copy?

Well, maybe you can tell that I really don't understand the whole idea of
why you would try to program an ECU with a limited interface when
significantly better interfaces are available for the same (a bit higher or
a bit lower depending on which you choose) price.  I'm still trying to
figure out whether electromotive, haltech, or one of the others are the
best, but I can't imagine that SDS is.

So one of you SDS users please chime in here.  Am I just missing something?
Like I said before, I'm sure it's possible to tune an engine to run really
well with an SDS system or any other decent system, but why would you want
to?


Like Mark said, SDS has a nice site, and its worth checking out.  Just don't
assume that because you have more information about them they must be best.

Sincerely (and hoping for someone who can tell me what's what to do so),

Brian Haygood




--
Email LIST problems to: scirocco-l-probs@scirocco.org.
To unsubscibe send "unsubscribe scirocco-l" in the message to majordomo@scirocco.org