For the record a 730 will work with $58 code, provided you use a SyTy calibration, with the harness repinned to match a SyTy and add a 2-Bar MAP sensor. I swapped out my 749 on the Malibu, and without ANY changes to the prom or harness(SyTy pinout), swapped in a 730 in place of the 749 and everything worked as it should.

Now mind, it is important that you use saturated (high imp) injectors, and wire the harness as a SyTy (see diy-efi ftp site for wiring diagrams) as a 730 only has one injector driver. The 749 has a second driver in order to run P/H injectors (4 with stock FETs) in the Turbo Sunbird, it is not needed if you use TPI injectors. cheers, BW

 

thats very very interesting.

I've got two berreta PCM's one from a 92 and the other from a 93, both say that they are not alt. service numbers for the 730 but they both look just like one.

I wonder how many other ECM's are fairly compatable?

I did a chip for a friend with a 87 S-10 and just used a 88 chip (no def file for 87) well it didn't work so i just swap the compelete computer and it worked fine with out any hiccups


BTW, does anyone have a picture of the cover off a 730????

 

 

hummmm...

Very interesting,

The two look alike 730's i've got have

1 16173278 has
2 pink and 1 soft blue looking color.

and 1 16156450 has
2 black and 1 light green

Sound familiar???

 

Hey Bob,

I figured it would work, but never got around to actually testing it. thanks a bunch, for shaking that out.

BW

 

That is good to know, that means with a reprogram and a repin on the harness my stock 730 ECM will work with a 2-bar MAP. You are the man.

 

Well thats good to know. I was gonna attempt it in the spring once I got the blower running right. Knew it was possible but never found anyone who said it's a definate. Now I guess it's one less thing to worry about, and I dont have to buy a new computer since I already have 2 730's laying around.

 

what are p/h injectors?

 

There are two types of injectors..

Saturated, or high impedence ~ 12-15 ohms

Peak and Hold, or low impedence ~2-4 ohms

Each has specific injector driver demands, P/H cannot be used with a ECM designed for Sat injectors, (at least in stock OEM form), however Sat injectors will work with an ECM designed for P/H injectors.

 

oh ok. i was used to seeing them as low imp. injectors.

so 'peak and hold' refers to the fuel delivery method?

 

This is good info! I've been looking for info on this swap. I'm currently running the Vortech FMU with a Vortech S-trim blower on my L98. Very soon I'll be running alot of different engine parts and I'd like more control over the tuning of my setup so I can make sure I get the most power possible. I had considered some of the other expensive FMU's but the SyTy ECM swap seems to be the cheapest. What would you recommend for someone running low boost like bar 1 or under? What would be the best swap?

Also, given that the stock 3rd gen ECU can interface with a 4th gen dash cluster, do you think the SyTy ECU will work as well? Or I guess more specifically, do you know if the output to the guages is different in the SyTy ECU than it is in the stock ECU? It uses VSS right? Sorry to go off on a tangent. Its hard to find people who have experimented with this stuff.

Thanks!!

 

Why would you need high imp injectors for a 7730 when TPI vehicles running a 7730 or 7727 use P&H/ low imp injectors? There should not be a need to change injector wiring. The 7749 has different Mosfet drivers, which are designed for high imp injectors, hence the need for a wiring change for 4 P&H/low imp injectors or a drive change to run more.


Thanks

Ed89

 

Thats because ALL TPI's use saturated (high z) injectors, not P/H's.
Checkem, ... ~15-18 ohms.

You have it backwards..

 

$58 code allows for either optical or magnetic VSS input. Simple flag in the bin. As far as cruise and such, should also work provided the wires are pinned correctly.

 

Your right. Thanks For straightening me out.

Thanks

Ed

 

Ok I'm sold. I want to do this. I'm sorry but I'm a NooB @ this $58 code deal. I'm guessing its something you need to use to edit the ECM code? Is there someplace I can read about what kinda hardware and software I will need? Or can you give me a quick rundown?

*Edit*: Ok I searched a little more and found a nice place to start. I read through here:

https://www.thirdgen.org/newdesign/tech/promintro.shtml

So basically:
Pull the chip from the ECM.
Read the chip using the programmer.
Save the BIN.
Open the 'other' software.
Load the BIN along with the calibration file.
Make the necessary changes and save the new BIN.
Load the programmer's software and load the new BIN.
Put a blank chip on the burner and program it.
That's it.

Will I need anything more advanced (hardware wise) than what they cover there? Also, where do I buy the $58 code? Thanks!!! I need to start reading up on this!!

 

Depends on your current system. A 165 harness will need changed to 90-92 F-body. From there a half dozen wires need moved around as the SyTy ($58) code changes some outputs. Ex TCC and an injector ground is in a different location than the usual SD code.

Bins of $58 can be found on the diy-efi site, or do a search on 749 in the prom board as I have posted all relevent info, diagrams, and a basic modded bin.

Bort62 did a write up of a 749 conversion he completed.
http://www.speedtoys.com/~bort62/7749/Main.htm

cheers, BW

 

You'll need a laptop, pocket programmer, some AT29C256 chips, tunercat or programmer 01 to edit the chip, datamaster or freescan to capture data from your car, a 730 or 749 ecm, a memcal from a speed density camaro or firebird, and a binary from a sy/ty.

 

Hey I wanted to thank you guys for all this great info. I really appreciate it!! The car I want to do the swap on is a 1991 Z28 with the L98. I believe it uses a 730 ECM. Lucky for me one of the guys in my club owns a Syclone, so have something to refer back to. I'm excited!!!!!

Couple more questions (sorry cant help it!!)

You've shown us that a 730 ECM can be modded to pull the load of a 749. (with $58 code, some repinning, SyTy calibration and a 2-Bar MAP sensor). Is there any other reason a 749 ECM would be better than a 730 with the above mods? Any other reason that could justify the cost of going and buying a used 749 ECM? (the second driver in order to run P/H injectors for example) Sorry I just had to check before I take my 730 apart hehe.

Also, if you did stick with the 730, what do you think about using a Accel Variable Injector Controller? Or would the better solution be to wire the harness as a SyTy like you sudgested?? An extreme example would be pushing 2 bar of boost?

Last one (I promise!!!), with the 749 ECM (or 730 w/ $58 code, repinned, etc) do you forsee any problems running an intercooler?

Again, THANK you so much!!!

Shawn

 

Originally posted by CrazyHawaiian [/i]Hey I wanted to thank you guys for all this great info. I really appreciate it!! The car I want to do the swap on is a 1991 Z28 with the L98. I believe it uses a 730 ECM. Lucky for me one of the guys in my club owns a Syclone, so have something to refer back to. I'm excited!!!!!

Couple more questions (sorry cant help it!!)

You've shown us that a 730 ECM can be modded to pull the load of a 749. (with $58 code, some repinning, SyTy calibration and a 2-Bar MAP sensor). Is there any other reason a 749 ECM would be better than a 730 with the above mods? Any other reason that could justify the cost of going and buying a used 749 ECM? (the second driver in order to run P/H injectors for example) Sorry I just had to check before I take my 730 apart hehe.

< Basically so long as your fuel demands are within the limits of the 730, roughly 55 lbs per injector, that you would need a 749 and the second driver. Now remember even a 749 needs upgraded to run 8 P/H's.

Also, if you did stick with the 730, what do you think about using a Accel Variable Injector Controller? Or would the better solution be to wire the harness as a SyTy like you sudgested?? An extreme example would be pushing 2 bar of boost?

< Don't have any experience with the Accel box, a 730 more than likely work for your needs.

Last one (I promise!!!), with the 749 ECM (or 730 w/ $58 code, repinned, etc) do you forsee any problems running an intercooler?

< no.

Again, THANK you so much!!!

N/P

 

Ok I understand the repining, I understand you need a chip with the $58 bin file, I dont understand what is refered to as sy/ty calibration.

 

Repin to '749 specs, and forget about $58.
Email myself, or better yet Grumpy and get $60 and start fresh.

Its based on the $58 code, but better, 32k, and the base calibration is more similar to a car than a truck (grand national!).

-- Joe

 

I'd love to get the $60 code from you. I'll send an email over as soon as i finish this response.

Is it going to be good enough to give me a decent base to start with on ~6-7 psi boost (stock Turbocoupe wastegates)

IE, can i input my injector size and start tuning with it from there?

If this is the case, great! But as I sit right now, I really don't know where to start with the turbo tuning or what would be a good base bin to use. hmmf


And...before i even run the turbos, can i run this mask without boost just to get around?

 

$58 dont have inj.size it has BPW vs EGR


The correct formula is: BPC = 730.75 * (vol of 1 cyl / inj flow in gms per sec)

BPC = 730.75 * (VOL / RATE)

; VOL = Vol of 1 Cylinder in liters
; RATE = Injector flow in gms/sec
;
; gms/sec = (lbs/hr / 3600) * 453.6

If you are using Tunercat:
Changes in tunercat editor
Edit step size 1
Minimum Table value 0
Maximum table value 255
Scale factor 1
to get the correct scale factor on BPW vs EGR

/N.

 

Just forget $58 and use $60. The Tunercat TDF for $60 is free too.

--Joe

 

you got PM....

 

http://members.cisdi.com/~anesthes/projects/prom/

-- Joe

 

Is there a copy of a base bin to work with there? I couldn't find one

 

I would also like to know of a base $60 bin to play with

 

download the 2bar.zip, change the source to match your parimeters, click on the exe to compile it into a 32k bin.

Try to get used to working in the source folks.


-- Joe

 

I have been searching for the proper IAC pinout for the 730 ECM using $58 code. The schematic at diy-efi matches my Snap-on book exactly for the SyTy. The snap-on book has always been correct for everything I ever looked up.
So, both the polarity and windings are reversed. The differential signals are inverted changing the direction and the A and B control bits are reversed.

730 (verified publications)
E3 Ahigh
E4 Alow
E5 Bhigh
E6 Blow

749 (diy-efi and snap-on)

E3 Blow
E4 Bhigh
E5 Alow
E6 Ahigh

749 (www.speedtoys.com)
E3 Alow
E4 Ahigh
E5 Blow
E6 Bhigh

Not trying to say anyone is wrong......just trying figure out what is right. It sounds like you used a 749 with $58 code and swapped it for a 730 with $58 code. That would work as you stated. If you swapped a 730 with $8D code in place of a 730 with $58 code or 749 with $58 code then it would not work.

The code is what makes the difference. It seems the GM programmers inverted the IAC bits going from the $8D to the $58 code. Note that the speedtoys pin-out is theoretically incorrect. It works because the differential signal (high/low) pins are swapped. The A and B bits just move the IAC.

Comments anyone?

J