[Gmecm] custom retro carb efi lookalike

[dozierhc at aol.com]

David...

Looking at the pictures, these injectors look to be high pressure side-feeds like found on Chrysler 3.5L V6s, or Densos on some Toyotas and Nissans.
If so, their impedence will be around 10 to 12 Ohms, so a high resistance injector driver would run them fine.

But it would be a very good question to ask the vendor before selecting a Control System ECM to work with them.

Hank



-----Original Message-----
From: David Allen <davida1 at hiwaay.net>
To: alan mays <truckeez at yahoo.com>; GM-ECM <gmecm at diy-efi.org>
Sent: Fri, Feb 24, 2012 7:02 pm
Subject: Re: [Gmecm] custom retro carb efi lookalike


That's a nice part. Really looks like a quality system.
 
The computer really only cares about the injector impedance (Z).  Typically - with Rochester EFI the injectors are low-Z with peak-hold driver circuit in the ECM, and the port injector systems are high-Z with a simple on-off saturated driver in the ECM.  Other than that, the placement of the injectors is irrelevent to the ECM hardware (the computer). 
 
The tuning is mainly to match the engine's airflow to the delivered fuel. Wether the injector is above or below the throttle plate, this wouldn't matter. What DOES matter is the volume of the inlet manifold which is wetted with fuel.  This is where the injector placement affects the tuning.  The closer the injector to the intake valve, the less acelerator pump shot is required. 
 
So for this unit, you would need a TBI-like curve for the fuel and acellerator pump shot. I didn't see the injector impednace on that website but the ECM hardware would have to match this.
 
Hope this makes sense - I am about out of time today!
David
 
 

----- Original Message ----- 
From: alan mays 
To: Gmecm at diy-efi.org 
Sent: Friday, February 24, 2012 5:45 PM
Subject: [Gmecm] custom retro carb efi lookalike







I was checking out the efi retro stromberg 97 from  



http://www.autotrendefi.com/efi_97.html  its got the injectors spraying just UNDER the throttle blade---  so its not throttle body?
 
 if the injectors were spraying just above the blade--it would be throttle body injection--and would have to be tuned as such?
  so the setup is technically port injection as long as the injectors are down stream of the blade --by even a inch,  and has to be programmed as port injection--and use a port efi computer?  




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