> We also needed to seal the
> slide throttle in case somebody floods the engine during
> starting.

Paul,
Wouldn't you need to make the slide throttle air tight!?
If it weren't air tight and sucked in some air, it would disrupt your air
fuel ratio.
To my mind that would mean you would have to separate the two throttle
slides and make each slide, sealed within itself (same as the butterfly).
As shown on the attached drawings the blue hatch are is sealed and the round
throttle control rod is sealed with a (red) 'O' ring.

If you don't like my ideas that's fine, but this is what I'm planning for
the single. However I've drawn it with two, to show how they might be
coupled for the 2 rotor.
George ( down under)

I have nothing against doing it that way. IMHO it is unnecessary
however.

Tracy's system uses the pressure in the intake manifold on the
down stream side of the throttle to adjust the amount of fuel
injected. That would include any air leaks around the throttle plate.
We T the pressure taps near the rotor housings from both
runners together and feed the signal to Tracy's pressure sensors.

The situation with a carb is entirely different. The flow sensor
is in the carb. Any air leaks downstream from the carb will result
in a lean mixture. Same goes for most automotive EFI systems
with mass airflow sensors near the beginnings of the runners.

BTW Tracy and I are having a bit of disagreement about how the
manifold air pressure should be monitored. Tracy samples the pressure
only once per rev so a random pulse or turbulence can give an erroneous
signal with a high speed pressure sensor. I would take several
samples and average the data. We will know more about this
next week. It is also easy for Tracy to check this as all he
need do is connect his oscilloscope to the output of his pressure
sensors while he is running the engine. Are you listening
Tracy?  I'll be glad to eat my words if he notices no
variation in the signal over a short time period.

Also BTW a carb mounted on the end of long intake runners is exactly
the same as locating the fuel injectors there as far as throttle
response is concerned. Since the runners on my Cont. O-470 are quite
long the carb is mounted down under the engine on the end of
those long runners I have no problems with throttle
response in a go around. With our current EFI set up on
the dyno engine we have noticed no problems with throttle
response so far with the injectors mounted out near the
end of the 20 inch long runners. Will check for it again when we
run the engine again next week.

Paul Lamar.

The throttle response with remote injectors is indeed good news.  Of
course,  we need to get that from idle on up but I am betting the
throttle response will be excellent throughout the rpm range.   Any
chance you will be able to bolt on Mark's exhaust system while still on
the dyno?     Jerry

I don't think so Jerry. Sorry. We are running out of dyno time
here and we have a wide band mixture monitor installed in the
current exhaust system. Maybe a quick test if the fuel mixture
from Tracy's EFI system using the new fuel pressure regulator
is in the ball park next week.

BTW stop the input tubes at the can skin. You don't want them
going all the way into to the center of the can. They need to be
trimmed at the surface of the large can.

Paul Lamar