hey guys
i read an artical a few years ago in chevy high performance, they stated that the accel/dfi uses the motorola hc-11 processor which is identical to the chevy tpi and older lt1 computers. my question is then obviously whats the differece except for the $ 1000 price tag. what am i missing?
thanks

 

Accel uses there own circuitry design and there own software. The Accel DFI has an RS-232 com port to connect to a computer, also. With the advances people are making in the disassembly and programming of the factory ECM, the DFI probably isn't worth it.

 

So would it be possible then to program the factory ecm to see boost? Or is it a hardware limitation in the circitry in the ecm?

 

That would depend on the ECM. GM already has ECMs used in boosted applications, (Typhoon/Syclone and GN).

 

I'm talking about the 730 ecm that is currently in my 91 Z28.

 

That I'm not sure, but if someone is capable of modifying the source code, they're probably capable of modifying the hardware.

 

Interestinly enough the syclone 1227749 and your 1227730 ecm use the same printed circuit board. Thou the 748 is populated a little different to use a wastgate (and couple other lil tweaks).

 

So is my 730 capable of seeing the input from a 2 or 3 bar map sensor? If it isn't it sounds like it may mostly be a limitation of the software coded on the eprom and not the hardware right? And in that case would it be possible to get coding from the Syclone eprom and incorperate it into the Z28 eprom to get the computer to make a useful response from reading a 2 or 3 bar map sensor?

I am somewhat computer savy and have experience moding bin and rom files in hex editors and also have some experience modding pcbs on video cards and motherboards. I have never had an ecm on a car appart, but if someone could give me some diagrams of the two different ecms for the syclone and Z28 and what chips do what I could probably do some soldering(steady hands) and whatever else it takes to make a 730 read a 2 or 3 bar sensor for supercharged applications. As I currently have a procharger on order and would be pleased to avoid the expense of an aftermarket ecm. And I would like my cruse control and emissions devices that my factory ecm controls to remain in working order.

 

Go to the DIY-PROM board and look at the intro article. There is a link to Ludis Langens? site and he has ecm schematics on there. The 749 and 730 may be two of them, at least. More than likely you won't have to do anything to the ecm but rather the code. Get a hac of ANHT and a hac of the SY/TY code and if you're good with code, make some changes so the code sees boost. I warn you, if you succeed, you may become an instant star as lots of guys with blowers and SD are dying for something like this. It has supppossedly been done before but I don't think any documentation has been done on it.