REFLECTOR: Re: Electronic Fuel Injection

[michalk]

I'm not ignoring you, I wanted to get some pictures.  Looks like I may 
get around to that this weekend.

Chuck Harbert wrote:
> Brian, I didn't know that you had a turbo on your Franklin. I'm 
> interested in what you did to match the fuel flow with the turbo boost?

I'm using an Aeromotive Fuel pressure regulator.  It has a fitting that 
attaches to the intake manifold.  It is adjustable pressure output.  I 
don't remember the range, I'd have to look it up.

> I get the sense that you used a throttle body (s) with electronic fuel 
> injectors, and then blow thru after the intercooler? Maybe you could 
> explain your system to me, if you wouldn't mind. If you have any 
> pictures, I'd like to see them.

I machined 321 stainless bungs, and TIG welded a 321 stainless intake 
manifold.  There are two injectors per cylinder.  One set, powered by 
the Autronic is of course electronic injectors, Bosch.  The other set of 
injectors are constant flow injectors.  I bought "mister" nozzles from 
McMaster-Carr that matched the flow rates I was interested in, then 
calculated the orifice required for that pressure drop for that flow. 
All of these hoses, six per side run up to a fuel manifold.  That's a 
lot of weight in hoses.  To make the constant flow injectors, I drilled 
AN-6 plugs.  On the flared end, tapped for 1/8 pipe to fit the nozzles. 
  On the other, tapped 1/8 pipe to fit an AN6 fitting for my hoses.  One 
of these days I may try to make a proper fuel rail.  The fuel manifold 
has two internal fuel galleys.  One galley runs at FPR regulated 
pressure, about 50PSI, or adjustable as needed for my tuning needs.  The 
second galley has a fuel pressure regulated by a barrel valve I 
machined.  This barrel valve is controlled by a stepper motor, that is 
controlled by my redundant battery backed EFI system that I'm doing the 
programming for now.

> 
> The reason I'm interested is that I'm turbo-normalizing my IO-360 using 
> a T-03 blowing thru a automatic fuel flow adjusting Bendix servo from a 
> helicopter. Initially, I'll be using a manual wastegate, plus a 
> overboost prv set at 34.5" (the helo servo was set up to handle up to 
> 36"). I'm not using a intercooler, and the ignition will be handled by a 
> Jeff Rose crank trigger driving a MicroTech ECU (which can also drive 
> electronic fuel injectors) (Slick mag as backup). Eventually, I will add 
> the electronic fuel injectors to the intake tubes, and turn the fuel off 
> to the servo (which will be an emergency backup). I used the MT ECU on 
> my previous AC engine and it worked well, plus it was reasonable cost. 
> Check out their website http://www.microtech-efi.com/index.html, but 
> don't tell them you are working on an AC, or they won't talk to you. 
> This is a true sequential firing system. I've got the turbo setup almost 
> finished and will install in the next few months.

This sounds very similar to my setup, minus the Bendix Servo.  My 
throttle body is a simple Bosh TB, that matched the inside diameter of 
my turbo compressor inlet.  I don't remember the ID, but it's maybe 2.5 
inches.  It has two small bleed ports, designed (I assume) to be 
connected to air valve solenoids for fast idle control.

> 
> You mentioned that you run 50 psi rail pressure which is great for 
> atomization, but hard on electronic injectors which normally run 
> 30-40psi, as I remember. Are these special injectors, or am I 
> misunderstanding your system? I agree that normal AC carbs or servos are 
> heavy and expensive, but I had a ECU failure and a forced landing that 
> could have been prevented with a redundant fuel system.

I'd have to look up the part number for these injectors.