Often the first thing that gets the axe on a performance engine is the egr equipment, same was going to be true on my project until it occured to me that I was letting a valuable function of the ecm go to waste. You could easily put any number of accesories in place of the egr equipment and have complete control of it's operation using the egr duty cycle table. Methanol injection, a wastegate/bov, even N2O could be controlled by the ecm! Of course the problem with this is that 1) it's not a very detailed table and 2) the rpm and LV8 (vac for the sd guys) it operates in are narrow, but I've got a friend that can help me hack into the programming to get around that. So how else can we put this thing to use? Secondary injectors maybe? Let's see some creative ideas.

 

Things like this have already been done back in the 1990's. Check out the DIY PROM board. I have all used up all the extra outputs on a 730 ECM. You can keep the EGR and use the outputs that GM didn't use.

Your idea is new to you, but others have already done it and more.

 

Nice to know it worked. So what else have people come up with? It'd be nice to have a list in one place. So...

-methanol/detonation suppresion
-secondary injectors
-N2O
-blower clutch
-exhaust cutout
-wastegate/bov
-2nd throttle
-coil(s)
-2nd fuel pump
-fuel reg
-thermostat
-water pump
-after-run oiler
-?

 

I'm mostly interested in secondary injector drivers, since I think I'll need to set up two stages for my engine to run right.

 

What size are they? I'm guessing it's rich at idle, right?

 

Using the appropriate injectors with an appropriate computer there is no need for secondary injector drivers. If you just want to use what you have and do it for cheap (like I tend to do) then you can add a couple injector drivers. Without the PCB it is about $5 worth of parts. A PCB will run $20 for custom fabbed unit. Or you could just hand wire it on a proto-board for $10.

150#/hr injectors are available. 16#/hr injectors are available. SEFI ECMs are available. Double fire batch ECMs are available. You can mix and match them for what your engine needs. If you end up with too rich at idle, then you need to tune it properly or change to a different fueling mode and/or ECM. If you can't figure that out, then there is NO WAY you are going to figure out how the fueling works inside the ECM and controlling outputs will always be a mystery to you. Some GM ECMs can be re-written so the handle fuel squirts in different ways. If you guys are interested in this stuff, go to the DIY PROM board. Not many people talk about ECM control/coding around here at the Power Adder board. If you are just looking for someone else to write some code for you and fix up your stuff for you then DIY PROM people will not help you in most if not all cases.

If you can't write code, run the control off of a Hobbs switch.

 

Just knowing the size won't mean anything. You need to know the RPM, VE, and fueling mode, etc. along with the size.

Example, 83#/hr injector at idle, big cam, double fire batch ECM........too much fuel foul plugs or erratic idle. Good for 1000+ HP at WOT in an 8 cyl.

Example, 83#/hr injector at idle, big cam, SEFI ECM........can be tuned to idle perfect. Good for 1000+ HP at WOT in an 8 cyl.

 

[quote=junkcltr;3369333]Just knowing the size won't mean anything. You need to know the RPM, VE, and fueling mode, etc. along with the size.[quote]Yep. I just wanted to know what size injectors he's using.

 

Gotcha.