Reply to "Stroker Motor Questions by Dave F #5972"

> I think that is the abilaty to tune each cylinder as indepently as necessary
> for maximum performance.

That's not why I'm going with IR EFI. I'm doing it to tame a big cam in
a 90 degree V8. Since the runners are isolated from each other, reversion
from adjacent cylinders does not foul the intake stroke, allowing a longer
cam duration with a streetable idle and better low-to-mid range performance.
Kirby Schraeder runs a PPC-sourced IR EFI system on his 377 cubic inch
Cleveland stroker (iron 4V heads with Weber lower and 48mm TWM throttle
bodies). He runs a fairly large overlap 288FDP Crower solid flat tappet oval
track cam on the street. Specs on his cam are 254/258 degrees at 0.050"
(288/294 degrees advertised), 0.569"/0.580" lift (0.022"/0.024" clearance hot)
with 105 lobe centers. That's a lot of overlap for a street car. According
to Kirby, with a 700DP Holley on a Ford aluminum dual plane intake manifold,
it had a wild idle and wouldn't start pulling well until 3000 RPM (Crower
rates the cam range as 3500 to 7000 RPM). When he installed the independent
runner EFI, the first thing he said was "Where'd my idle go?". He noted it
now pulls 5th gear from 1500 RPM. Kirby also noted it's tough staying off
the 7200 RPM rev-limiter in lower gears.

Independent runner also allows tuning of the inlet tract length generally not
possibly with single 4 barrel plenum type intakes. For my stroker engine, I
needed relatively short runners. Longer runners increased low and mid-range
torque but that came with a big loss of HP in higher RPM ranges.

> How much more complex is a v8 with an IR setup? Isn't it something like 8
> to the power of 8?

No. It's not that much more complex. In fact, Ford used their EEC-IV
speed density computer on their IR EFI F1 Cosworth V8's.

> Add to that a system with no oxygen sensor and a mathamatical compromise
> between TPS and MAF.

What system are you talking about that doesn't use an O2 sensor?

> I didn't intend to get into a technical discussion with people who obviously
> have vested interest in the marketing of these systems.

Who here has a vested interested in the marketing of these systems?

> Not to doubt anyone or be argumentative, but I presume that those of you speak
> from practice and not theory and have used all of the formentioned systems?

Speed density and mass air EEC-IV experience yes. This will be my first
IR EFI system but a couple of my friends run them and love them.

Dan Jones