New to list, have a question.

[esc]

>Eric,  I also have an early ProJection  ....  doesn't have the EGO
>feedback though.  This is probably not going to be any real help
>to you, but I thought I'd share some quick thoughts with you
>
>  . the projection is an alpha-n controller -- only uses rpm and
>tps to determine fuel flow
>
>  . the temp input is, as best as I can determine, basically an
>on-off kind of thing to enrich the mixture and energize the throttle
>kicker, so I don't consider it a bona fide "input" for normal
>operation

Correct, it does nothing once the engine reaches normal temp.

>
>  . the "ego feedback" unit is only to keep the system closer to
>stoic ......  a problem I constantly have is the unit always runs
>rich .... it can be adjusted leaner, but then it will run entirely
>too lean at certain points (I have a DPM watching an EGO, so I
>get a little "feedback" myself  ;-)

I have an old K&N O2 guage that I used before I got the closed loop kit.
I still use it for base line tuning, it is very helpfull.


>... if you agree with the above (that the ego feeback is to try to
>keep the unit from running so rich, and maybe to prevent the operating
>points where it also runs too lean, and that it's not to really improve
>on the operating characteristics of the unit ....)

It does help my mileage a lot, at the expence of throttle responce.  Thats
why I installed an easily accessed disable switch for it.

The main problem I have with the Closed loop kit has to do with how it
modifies the TPS voltage.  Generally the baseline mixture is too rich so it
leans it out.   If it(closed loop kit) leans the mixture very much then
when you give a little more throttle it gets very lean and does not
accelerate properly.  This kit does not function above 2/3 throttle, so I
find myself often applying a lot more throttle than would otherwise be
needed just to avoid the closed-loop-kit-induced flat spot.


>  . then, consider that a MAP input might be more logical ??   I had
>entertained the idea of either building my own ego feedback unit or
>a map feedback unit -- or could actually sum the two together ??  All
>that's needed is to sum the input from the tps with the conditioned
>voltage(s) from the other devices.  To me, the map input makes more
>sense and would elevate the unit from the status of simple alpha-n
>controller to a simple speed-density unit (which their literature
>claims it is anyway!).
>
>Tom Cloud <cloud at peaches.ph.utexas.edu>


I agree that a MAP input is what I need.  Without it the Ram-air system
will always be troublesome.
The problem is how do I do it?

I really like the throttle body part of the ProJection, but thats the only
part I really want to keep.  I'm not all that happy with the controller.  I
really want something that I can have more control over and that will
accept input from more sources.

Eric
esc at firstnethou.com
If it breaks, make it stronger.
If it doesn't, try harder.
'68 Big Block Bird
'69 Spitfire
'82(sort of) Camaro