Bench racing ecms

[Scot Sealander]

Gregory A. Parmer wrote:

> I've got my '7747 running on the bench (wall actually) and
> if you plug in the real injectors the power supply doesn't

I usually use a 12 VDC wall-wart.  You know, those things you plug
in the wall...  As long as you don't power up much, they work great.
They are only a few bucks.

> Problem I'm having is getting the intended feedback. Surprisingly
> enough to me, PW seems more closely tied to MAP than TPS.

I have been preaching this for a while.  TPS is not in the fuel equation,
at least not directly.  

> On a real engine opening the TPS would reduce MAP and thus
> increase PW. On the bench MAP doesn't change (just because
> of TPS) and blipping the TPS generates only an increased
> PW during the blip..similar to an accel pump. Go figger!

That's what TPS is mostly used for, transients.  It also has
some purpose for other things, like TCC lock-up.

 
> I'm wondering if it'll be OK to just fool the ECM into thinking
> it's always right...ie, lots of stoich crossings via a wave gen 
> of some sort.

No way.  It is a closed loop controller.  It sets a condition, and
expects a result, at the right time.  You can't just send it stuff.


> > Your idea of an engine simulator, at whatever level, is right smack 
> > in the stateOdeArt of electronics. Is that SCARY, or what?

This is from a previous post, but it is a long way from state of the art.
I remember that someone from Linc, (the flight simulator company) was
writing one on his own time about four years ago.  He left Linc as I 
recall.  Not sure what happened to him, or his simulator.
  
Scot Sealander   Sealand at clarityconnect.com