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Old Nov 20, 2007 | 04:22 PM
  #1  
crazywill's Avatar
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From: cincinnati
Car: '89 formula
Engine: 415 small block
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dual tbi

anyone know if you can run a second ecm on most of the same inputs trying to run a dual tbi cross ram setup
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Old Nov 20, 2007 | 04:40 PM
  #2  
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Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Welcome aboard thirdgen.org.

Hmmm, interesting concept. I'm sure I haven't heard of anyone who's tried it (but I don't spend much time on the TBI forum).

Theoretically, I'd think you'd want an O2 sensor in each bank, and to make sure what sensor input goes to what ECM. Since it's a batchfire system, it shouldn't care about the fact that it's only feeding half the cylinders that are firing. Any idea what size injectors you'd be using?

Are you the winning bidder of the manifold?
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Old Nov 20, 2007 | 04:59 PM
  #3  
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Car: '89 formula
Engine: 415 small block
Transmission: 700r4 till it blows
Axle/Gears: 7.5 rear,forged axles,3.73 cogs
Re: dual tbi

stock 305 injters w/ 454ss prom
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Old Nov 20, 2007 | 05:16 PM
  #4  
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
This is for the 415? What cam are you running? Overlap/LSA can drive O2 sensors nuts.

Being a speed density system, I'd guess you'd have to do some custom tuning, regardless what PROM you started with.
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Old Nov 20, 2007 | 05:50 PM
  #5  
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From: Moorestown, NJ
Car: 88 Camaro SC
Engine: SFI'd 350
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Re: dual tbi

The dual TBIs can make idle and tuning somewhat difficult, but its been done. Modified TBI ecms with dual injector drivers are available for around $300 or so that allow you to drive all the injectors with one computer. Youll also need some custom linkages to drive the slave TBI as well. Properly tuned, it should make good HP. Also if your planning on making less than 450 HP, a single BBC TBI will work just as well. Add a good single plane intake, and your good to go.
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Old Nov 20, 2007 | 05:51 PM
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Re: dual tbi

I haven't seen one of those old things in a LONG LONG time....

Seems like an awful lot of work to put yourself through, for little or no derived benefit, to try to use 2 ECMs.

What would 2 ECMs do any differently than 1 ECM?

An easier way would be to just use any S/D computer, such as a 90-up TPI; and hook up each TB as if it was one bank's injectors. Use one of them's TPS.

A more important problem to overcome than the electronics, which is basically trivial, is getting the 2 TBs synchronized properly (mechanically).
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Old Nov 20, 2007 | 09:10 PM
  #7  
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From: cincinnati
Car: '89 formula
Engine: 415 small block
Transmission: 700r4 till it blows
Axle/Gears: 7.5 rear,forged axles,3.73 cogs
Re: dual tbi

who makes these ecms w/ the dual drivers this would simplify my delema thanks
----------
forgot to add twin turbo application and i know a stand alone unit would rectify this but don't wana drop $3,000 for one that will do what i want w/ dual throttle bodies

Last edited by crazywill; Nov 20, 2007 at 09:13 PM. Reason: Automerged Doublepost
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Old Nov 20, 2007 | 09:21 PM
  #8  
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From: cincinnati
Car: '89 formula
Engine: 415 small block
Transmission: 700r4 till it blows
Axle/Gears: 7.5 rear,forged axles,3.73 cogs
Re: dual tbi

i have the mechanical linkage for this intake i'm just going to tweek it for use w/ the throtle bodies this application should make 1300hp ball park@ 30psi
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Old Nov 20, 2007 | 09:34 PM
  #9  
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From: cincinnati
Car: '89 formula
Engine: 415 small block
Transmission: 700r4 till it blows
Axle/Gears: 7.5 rear,forged axles,3.73 cogs
Re: dual tbi

255/262@50 lsa 114
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Old Nov 20, 2007 | 09:41 PM
  #10  
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Re: dual tbi

who makes these ecms w/ the dual drivers
A small, little-known company, you'd never think to get auto parts that had been made by them, especially for one of these cars...

GM
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Old Nov 20, 2007 | 09:43 PM
  #11  
crazywill's Avatar
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From: cincinnati
Car: '89 formula
Engine: 415 small block
Transmission: 700r4 till it blows
Axle/Gears: 7.5 rear,forged axles,3.73 cogs
Re: dual tbi

for what application
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Old Nov 20, 2007 | 09:45 PM
  #12  
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Re: dual tbi

As stated earlier:
90-up TPI
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Old Nov 20, 2007 | 09:50 PM
  #13  
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From: cincinnati
Car: '89 formula
Engine: 415 small block
Transmission: 700r4 till it blows
Axle/Gears: 7.5 rear,forged axles,3.73 cogs
Re: dual tbi

thanks $25 a pop local junk yard can't afford not to try it
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Old Nov 20, 2007 | 10:00 PM
  #14  
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Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: dual tbi

The company is called DynamicEFI. The TBI ECMs fire the injectors 2x as often as a MPFI ECM. This means that the engine will be starved for fuel. You are better off starting from something that will work.
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