Reply to "Ultraflow EFI Intake Manifold"

> Steve Wilkinson says that the IR EFI that Pantera Performance was
> selling was discontinued because it didn't run well.

Kirby Schrader sure liked his.

> It ran on a Haltec and didn't have enough parameters to adjust to
> differences in altitude, temperature, hto starting, etc.

The Haltec ran in an Alpha-N mode using RPM and TPS. PPC also offered
a manual trim knob which always struck me as odd.

> Dan Jones suggested that an IR EFI system be run with a program that
> combined TPS with MAF. That would mean that every throat would need
> it's own MAF sensor.

I said no such thing. I suggested blending Alpha-N and Speed Density.
Primary inputs are RPM, throttle position and MAP (manifold absolute
pressure). You can run IR with a MAF sensor (using a single MAF sensor
in one stack) but since flow goes both ways in the stack, it will get
confused.

> Kinsler says their system (TPS) runs fine.

Alpha-N (RPM and TPS) alone will run just fine but blending with
speed density will give better fuel economy and part throttle.

> TWM says the system is $3200 but needs a $6000 computer to run right
> and I have to program all of the variables. That means I have to
> drive to Pikes Peak and program in all the altitude data.
> Then I have to drive to the Yucatan and program in all the jungle data.

Computers are typically in the $1000 to $2000 range. Kelly Coffield
should be able to give you a good idea about what a full on IR EFI
system for Pantera goes for now but I know it's much less than
what you are quoting.

> How does the Ford EFI factory program adjust for these variables? Or
> doesn't it? Do you mean that the Ford factory data can't be downloaded
> and used to run an IR EFI with TPS if there is no MAF?

Ford's EFI assumes a plenum intake and single throttle body.
The logic is not tailored to IR. Ford ran an EEC-based IR EFI in
Formula 1 but didn't use MAF since it was considered a reliabilty
problem given the vibration environment. My guess is they used a
speed density EEC-IV with no MAP input and tailored the table lookups
from there. Speed density alone would not work well because of the
nature of IR (all runners go to near atmospheric pressure within small
throttle openings, rendering the MAP sensor useless).

> The conversion of the Trickflow 351-w EFI to the 9.2 cleveland had a
> lot of program issues using the Mustang CPU.

The Ford EEC-IV has been hacked but it wasn't designed up front to be
programmed by the user. It's not completely understood by the aftermarket
tuners and only certain parts of it are user addressable. The aftermarket
tuners also only support the MAF EEC's, not the speed density EEC's
which presents problems when using large overlap cams. The GM computers
have similar problems but were hacked earlier and are generally better
understood.

> This looks like a $10,000 buy in package and $50,000 worth of development
> time.

Or not.

> I'm scared. The Webers are looking good again.

You've got the same tuning problems with a carb and it's a whole lot
easier to datalog, read a wideband and make a few keystrokes to change
a table than it is to take the wrenches to a carb. It's good to start
with a map working on an engine similar to yours but many of the
controllers have built in models that will generate a starting point
map.

Dan Jones