Reality of Fuel Consumption

[Tom Cloud]

>Tom, et. al,
>    The system that you described is available now.  Look at GM's TBI 
>from a late '80s truck, or the Holley or Edelbrock copies.  They are 
>basicly the same thing (just quadruple the price for the packaging and 
>ease of adjustments).  I mean the EFI system from an '89, or '93 even 
>350/454ci V8 should flow decent amounts of air and fuel for just about 
>any project.  The harness is available from almost any junkyard, or they 
>can be bought new from GM or Summit.  We know that the ECMs must be 
>easier to program than many VCRs due to the fact that aftermarket chips 
>are less than $100 US, and that there is at LEAST one place on the web 
>where you can buy a complete system to reprogram the PROMS (less than 
>$400 US).  The TBI system is the best of both worlds (tunability, and 
>economy), but SEFI blows it away (once the secrets of the box are 
>revealed...).    Just a thought.

>       *snip*

>>  seemed to share my feelings on this .... I'd think a TBI
>>  (or CPI, as Ford calls it) with MAF would be the "end-all
>>  to be-all".  I know of no one who's done this, but it would
>> allow the use of current carb intake manifolds, and would
>>  be self-adjusting.  I know that the window for this is small,
>>  only encompassing pre-efi cars, but there's still lots
>>  of them out there that probably would convert if the price
>>  were right -- esp if they could have the economy and reliability
>> of efi with the big PLUS of better emissions control.
>
>>  Tom Cloud
>
>Barry Coleman

Barry, how easy are these systems to modify to different
engines and then to program/re-program ??  And then what
kinda bucks are we talking ??

I'm real leery of 'chips'  ....  how can someone make
a chip for my app that's perzact ??  Seems to me that
the best they can do is make a best guess and then intentionally
err on the conservative side as there's too many variables
to consider.  And then, what if you change tire sizes or
diff ratio or intake or exhaust or cam or .....  do you
gotta buy a new chip ??

And then, you're talking chevy .... how's that going to
retrofit to a 'real' car (read FORD  8^)   If this is
a TBI, then *should* be no prob .... but if it's TPI
seems to me we're in deep doo-doo.

where's this place on the web that has programmers for
*any* price ... do they give out necessary info to make
major changes ??

What I'd love to see (wouldn't we all) is a flexible,
expandable system that has a hand-held, CHEAP programmer
that will do a bang-up job and then a port for a lap-top
for those that want that extra 1/100 hp and .05 mpg  ;-)

I'd think a reasonable price for a complete efi system
using TBI would be $300 -- including a hand-held analyzer/
controller that works sorta like the old dwell/tach test
sets except with the ability to vary some basic parameters
(e.g. fuel vs TPS, MAP and RPM) with a readout showing how
much correction was being made to correct to EGO stoich
 -- and if it was out of range (and which way).  This would
yield a fantastic device that would satisfy virtually all
our demands (I'll bet).  The "kit" would have some nomograms
that would allow the selection of injector and TB sizes before
the purchase.  The addition of MAF would make it more self-tuning
but I think it would be totally unnecessary as one wouldn't
need MAF if the SD system were easy enough to program.

With such a system as above, one could install it on
his standard carb-style manifold or even on a TPI manifold,
since the basic tuning parameters wouldn't change (i.e.
the fuel vs. RPM, TPS, MAP, etc).  That way, if one already
had TPI he could still use this system.  With what I'm
suggesting, one could "probably" pass all emissions tests
**and** have a bad motor-scooter at the same time (probably
a w*t dream).   8^(



Tom Cloud