Chip programming tutorial..?

[KEVINS]

I've been interested in playing with my own chips for 10yrs now but I know NOTHING about how to do it or what program is needed to do it. I'm only interested in playing with the timing to test some theories, but I have never seen what these "programs" look like that go into the eprom or how to even change the timing in them. An EE friend of mine could burn the chip for me if I ever got that far but for now I just want to learn how to actually change the timing table.

I believe I can use TunerPro to modify the timing correct?

If so does someone have a chip program that they would be interested in allowing me to look at and also identify where the timing tables are so I can look at them?

Better yet would be a video tutorial on how to change the timing in one of these programs but that's probably asking too much.

I'm sure I am simplifying this process more than I think but if someone would be willing to share their experience that would be helpful.

Thank You
Kevin

 

[87GN_70GS]

Check the gnttype.org website, lots of info there.

 

[KEVINS]

Check the gnttype.org website, lots of info there.

I tried, but became frustrated b/c I can't seem to find anything with the search function.

KS ={

 

[87GN_70GS]

I tried, but became frustrated b/c I can't seem to find anything with the search function.

KS ={

If you think you'll be programming overnight, Bro I got bad news for ya. It's gonna take some patience and reading/research.

Start here:

http://www.gnttype.org/techarea/chips/chippage.html

There are a lot of nuances not covered in the articles but were discussed on the boards. It's just going to take some studying.

 

[TurboDave]

No you cannot make such changes via TunerPro. Our chips are very simple PROMs that require a complete erase and re-write with every change you make. They are NOT flash memory chips like modern day chips are. Some of that info in the link provided by 87GN_70GS is mine. It took years of study/research to figure out what is going on in these chips, and then figure out how and what to change and not blow the engine up. Even that technogy has been far surpassed by experts like Bob Bailey and Erik Marshal with their feature rich chips that allow user adjustable features.

 

[BobbyBuick]

Ive got a pocket programmer .old dos unit .I would like to learn about it also .Only thing I bought it for was Max effort to burn a chip when Steve would give me something new to try out .I know how to copy and burn a bin file past that im lost

 

[JayC]

I think there is a commented dump of the ECM source code on GNTTYPE. I probably still have the documentation somewhere... Maybe Ill scan it into a PDF.. Its about 600 pages tho I seem to recall.

 

[87GN_70GS]

I have an old program called "Tweaker" by Mike Pitts which would be a good starting point. It's a windows-based GUI chip editor. It does "some" of the chip editing you would need to do to a stock bin image, but not all. It may still be on the gn-ttype.org site. Vbrun300 needs to be in the same directory as tweaker

 

[87GN_70GS]

deleted

 

[87GN_70GS]

Here is the stock commented code
Also, you will need a stock bin image to start with for Tweaker

 

[87GN_70GS]

Here is a '89 Turbo TA bin

 

[87GN_70GS]

Here is a text dump of the FBI chip

 

[87GN_70GS]

Some notes on using tweaker:
Injector constant, wastegate coefficient, idle smoothing, 3rd and 4th gear boost scaling, PE (power enrichment) fuel trims, BLM lock on MAF code, etc are not in there. You'll have to get a stand-alone hex-editor to edit those.
The stock highway lean-cruise A/F never worked. Lots of timing at very low LV8 did help gas mileage though.
The stock computer will throw up if the check sum is not right.

 

[87GN_70GS]

Here is the infamous Carl Ijames BLM lock patch:

"Dug through some old archives of mine and found it. This version sets the currently used blm (not the value stored in blm15, that's left alone) to
128 whenever the tps is >= 50%. Other %'s are easy, just look at the comments. If you like experimenting, I also did a patch to lock the blm when the maf is > 220 or so, instead of using tps. That way you use the learned value for part throttle and spooling and only lock it when the maf is about to run out of range. I also started locking it to 150 instead of 128, to make sure that it goes richer and not leaner when it locks. That way, also, the amount it changes is based on fuel pressure. High pressures drives the blms down so it gets lots more fuel when it locks, since you generally only have the fuel pressure cranked when you also have the boost cranked and need the fuel. Low boost and consequent low fuel pressures raise the blms so going up to 150 doesn't add too much fuel, so it's kind of self-correcting and sounds better to me than locking to 128.
If you lock to 150 you need to take 150/128 = about 17% of fuel out of the pe/rpm or pe/tps table. It will take some time for me to dig that one out, since my company has me in Boston most of the time and my notes are back in Maryland, sigh . I even tried replacing the pe-tps table with a pe-maf table to bring in the extra fuel gradually as the boost came up, hoping it would spool better, but it didn't seem to help. Anyway, enjoy.

--
Regards,
Carl Ijames "

 

[JayC]

Injector constant isnt in that version? Are you sure? Its not called "Injector Constant", its just called Injector Size. The software coverts it once you put in the lbs/hr of the injectors.

 

[87GN_70GS]

Injector constant isnt in that version? Are you sure? Its not called "Injector Constant", its just called Injector Size. The software coverts it once you put in the lbs/hr of the injectors.

I must have an older version (1.20), mine doesn't. Might be helpful to post any newer versions here or on gnttype

 

[JayC]

I dont have any of them any more. I had the Pro version for a while which did a lot more. Tuner Cat (If thats still around) is a minimal investment for anyone wanting to do their own chips and what I would use.

 

[dennisL]

Kevin, if all you want to do is experiment with timing then you'll need the following:
1. a bin file of the chip to modify (pick one that you like or suits your car). Your friend with the prom burner can make the file if necessary. Just give him the chip to read.
2. an Editor program that displays the value of each location (address) in the bin file, allows changes, then saves the new file. Data changes require a new checksum for the bin or it can be disabled it in the chip. Before I wrote my own editor program, I used WinHex but there are others that are fine.
3. Your friend burns the new bin file into a blank PROM chip.

The commented spreadsheet from GNTTYPE indicates where the timing tables are in the chip.
As always, you need a good scan tool (preferably with logging) to help analyze the changes.

You can use this forum to post questions as you go along. There are several very "chip savy" people here.