Is it possible through prom tuning to make the TPI system act as a sequential system versus the batch fire system that it is I know changing to DFI will accomplish this but i would like to know if it is possible through prom tuning first. thanks

 

With the stock ECMs, no. The stock ECMs do not have the necessary "drivers" on the ECM to allow you to operate as SFI.

However, Bruce is looking at the 8051 PCM from later year 4th Gen F-bodies (I can't remember the exact year ... 1994 I believe with possibly 1993 and/or 1995) and modifying them to be used on 3rd Gens. SFI would be a part of the conversion. You would have to talk to Bruce more about this (8051 PCMs) about the current status and major obstacles.

 

Thanks!

 

Maybe Bruce will jump in and give us a little information on the project if he gets time?

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89 IROC-Z 350 TPI

-Flowmaster Catback
-Performance Resource Chip
-700R4 (Rebuilt) Too much done to actually list
-K&N Airfilters
-Ported Plenum
-2.77 Gears (not much to brag about but eh, its there)
-MSD 8.5 mm plug wires
-Gutted cat
-!AIR
-Gutted Air Boxes

 

All the default modes of the 851 go to a batch fire strategy, from what I've been able to tell. The ecm does have to have a high, and low resolution timing input. The simple answer is making a distributor that uses a Optispark timing wheel and sensor.

IMO, the only real advantage other then when running huge injectors is for the DIS or CNP coils (Coil near Plug). But, FAST has just released the eDIST which allows for CNP conversions. Using a MSD Distributor so that you can get a cam synch signal, you can convert to something that is really state of the art downside is it gets expensive, you need 8 of the LS1 coils, plus the eDIST.
The LS1 coils are really amaziing. I've been playing with one, and have a eDIST and it looks really neat on the inside, just need to find 5 more coils, and plug wires. They use a Bosch connector instead of GM for some reason.

 

Forgot to mention:
That at over about 2,500 RPM, there is no differnce SEFI to batch, and at WOT the that number drops to much lower.

ie the intake valve is only open 25% of the time so the second the injector PW is over 26%, the difference between the two stops.

Also, lots of GN switch to Batch from SEFI for racing. Just disabling the can sensor input to the ecm defaults to batch fire.