7747 batch fire...
 

I've been reading a lot of older posts about running TPI off a 7747 ecm and have found several different answers......

First off, if I build a tune port intake, can I run it off a 7747?
Second, how do the 7747 injector drivers get hooked up?
Which leads to...third, will it run batch fire or bank fire.

I've read answrs ranging from "the 2 drivers can't handle 8 injectors" to "It will run 8 high impedence injectors off the 2 drivers" to "there are 4 drivers and it may/maynot work" to Run everything off one driver.

Finally, what are "saturated" injectors? I seem to have missed exactly what this means.

There was a lot of reference to the MPFI setup sold in Summit, but I'm not buying one of those, so it's kind of irrelevant.

Somebody must have tried this by now.

Any clarification would help.
-Mike

It ping-pongs back and fouth from injector to injector. Basically, each bank would fire twice per revolution in sync fire. Not quite sure how that would fly. With just one injector driver, it would be two fires per revolution for all. Each stratagy can cause pulsewidth issues as there are 2x as many firings. Additionally, youd want to completly block async fire, since that will fire alll the injectors at 80 Hz. Not what youd want with a port fuel system.

Saturated injectors are high resistance injectors. Even though the TBI ecm is peak and hold, it should run those ok. You may also be able to run low resistance injectors on each side provided the resistance that each driver sees is comprable to ~1.2 ohms. Dont know whats available injector wise for this.

Finally this has been done, but Id think youd be better off using a 90-92 TPI ECM. Its alot better, and much more suited to the task. Unlike the crap TBI ecm code, the stuff in the TPI ecm will be true SD and will work much better then the half-assed stock TBI stuff. I think youd be much happier in the end.

Moved

Re: 7747 batch fire...