Re: BPW and Cylinder Vol.?

[rr <RRauscher@nni.com>]

When dealing with an engine that is completely different from anything
gm put out, any starting ve table is going to be way off. When in
closed loop, the int can swing so wild that you can't follow it.

Forcing open loop and 14.7:1, it's easier to get most of the ve table
on the rich side first. Then enable closed loop and fine tune.  Even
for this it's best to lock other variables in place.

Been thinking that spinning the engine with a motor and measuring
the airflow at each point in the table should be a good start.

BobR.

Roger Heflin wrote:

> On Wed, 14 Jun 2000 rrauscher@nni.com wrote:
>
> >
> > To force open loop, set the enable temp to the max value. For
> > tuning the VE tables, also set the open loop afr ratio to 14.7.
> >
> > On the '747 there are two tables to change, one for the afr
> > vs. temp., and the other is afr vs. map. In this manner, you
> > can then 'discover' what the ve is at each point in the table.
> >
> > This is really tuning in reverse, but hey, it works <g>.
> >
> > BobR.
> >
>
> I am still trying to figure out how you guys are tuning this way.
>
> My thought on tuning was to leave the computer closed loop, and then
> based on how far the computer adjusts the BLM/int's at a given
> point then adjust the VE at that point based on that until things get
> reasonable close.
>
> Will this procedure work?   I am going to be tuning a new engine in
> the next month or so, (the old engine spun a rod bearing (130k)) and I
> will be trying to get things right this time.   The new engine should
> be putting out somewhere around 450-470 hp at the rear wheels, the old
> engine was doing 370 rwhp.
>
>                         Roger