"Michael D. Callahan" wrote:

    Jim's right, for the upstream injector setup to work correctly it

should

not make any turns, especially in a round intake runner, as it will

cause

fuel to adhere to the outside of the runner and defeat the purpose of
injecting it upstream to begin with. Making the runner oval shaped would
help the situation as would leaving the inside surface slightly rough in
order to energize the boundary layer a bit and keep things stirred up.

    I plan to leave one set of injectors on the housing, though for
go-arounds. You'll never get instant throttle response with everything
travelling that far. Another bit I overheard at OSH was that the F1(auto
racing) setups have two complete sets of injectors, one at the ports and

one

way upstream. If the driver stabs the throttle, the computer fires the

port

injectors until the engine catches up and then switches to the upper set

for

peak power and economy.

Tracy Crook wrote:

This matches up with what Mazda does in the car.  The secondary injectors
are further upstream than the primary injectors which are right in the port.
Mazda (and my EC2 controller) uses staged injection where only the primary
injectors operate at low to mid throttle, then open the secondaries at mid
to high throttle.   I did not have to implement an "accelerator pump"
function to get good throttle response with this setup.

Tracy Crook
rws@altavista.net
www.rotaryaviation.com

I, like Mecanair, am putting all my injectors out near the bells.
Fuel consumption to me is way more important than throttle response.
Cars, like RX-7's, need good throttle response airplanes don't.
If necessary I will add injectors and use a 555 one shot
triggered by a push button switch :-).

Paul Lamar
 
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