2002_Z28_Six_Speed

iTrader: (19)

A higher cat temp might make it work better. I am not sure. The cat temp has to be regulated either way.

One thing I do know is that after you go leaner than 14.8-14.9 there is alot more NOXs being produced. If you get 5% better processing at that higher temp and you produce 10% more NOXs then you are still loosing.

That would be the only explanation I could think of. I have a graph of CO CO2 NOXs ect v. AFR at home. I could post it.

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One thing that interests me is that I have EFI Live and I am fairly sure it can not flash an uncompressed binary. Hmm.....

radkon

iTrader: (2)

Lean cruise has been banned in the US for emissions reasons only. Below is a graph dipicting why.

From what I've read (http://www.designnews.com/index.asp?...Dthirty%2Byear), you need get the AFR closer to 28:1 to get all polutants to equal the same as our 14.7:1

Running lean cruise on mine I can pull down about 26 MPG on the hwy with 380 RWHP and AC Glad I drive a Holden

joe0121

Interesting, thanks for posting up the chart. Seems GM is pretty savvy about keeping us away from parts of the tune that are not legal to mess with.

2002_Z28_Six_Speed

iTrader: (19)

Oh, yea. Cause you know Kent Helfrich is going to come over here and kick our asses....

I say it is worth pushing onward with. It is 10+ years old.

89 formula350

iTrader: (8)

I am more than happy to help with this but for me I just wonder if I should skip it and go to the gto pcm/code (since I have my car setup as '98 camaro tune)

older gm pcms (fully hacked code already) are easy as it was there as well but only required a simple enable in the code. it sounds like this maybe along the same line just a few more unknown hoops to jump through


just was wondering if a oversea f-body would have it enabled?

2002_Z28_Six_Speed

iTrader: (19)

This article is interesting. This guy claims all Motorola 68332's have a special on board port with which you can set the break points, step through code, ect

http://www.diy-efi.org/gmecm/ecm_info/32bit/dumpflash/

This means if you had the interface from Motorola you should be able to program any PCM with a 68332 and dump or upload a bin.




It could be worth it to search the OEM site and see if such a device is offered. This guy built an interface but it only works with windows 2000 and is slow.

Jpr5690

iTrader: (13)

Dam... This Is Complicated

joe0121

Never said it wasnt worth it, they just put steps in place to make it difficult.

ryansm1

iTrader: (8)

You can find information on the BDM interface in the CPU reference manual. I am not sure why you would want to go to the effort of modifying the PCM to incorporate the interface, as you already have a method of dumping and flashing the memory. Additionally, unless you plan on building a bench harness for the PCM (with the ability to simulate sensor inputs), having access to the BDM is useless; with the PCM in the car, the ability to set breakpoints is equivalent to having a kill-switch. You would be better off finding a disassembler/debugger for the 68332 (hint: IDA).

You have all the information needed in the thread to modify your binary to enable lean cruise (at least for EFILive/Tunercat people). I'm almost positive EFILive is using ZLib to compress the tunes. Aside from that, you know what to search for in the disassembly (or hex, if you choose to use such) and how to calculate the checksum for the operating system.

2002_Z28_Six_Speed

iTrader: (19)

I got the pro IDA tonight and am loading it up now. The problem was I had the free IDA but it wouldn't decompile anything other than Intels. I got the license for an IDA Pro program tonight from a computing friend. This is a 500 ish dollar program for anyone wondering.

The problem I wonder about now is if I mod the bin I have to have tunercats to upload it as an uncompressed bin with or without checksums.

I know what a library is but I will have to figure out more about what segments are and are not in the .tuns to use EFI-Live to flash my PCM. Also, I need to look up more about Zlib. One of my computings friends said he might be able to help with this part.

My line of thinking was that I could upload an uncompressed bin to the PCM through the BDM without having to buy tuner cats or learn how to mod this to work with EFI Live.

Either way I am having fun learning about this.

ryansm1

iTrader: (8)

EFILive will open the raw binary files just like standard tune files. I think it will recalculate the checksums for you, but you might want to verify that.

I wrote up a quick test file that attempts to decompress a *.tun from EFILive into raw binary. I saved one of the raw bins with EFILive and attempted to convert back to binary, but haven't gotten much in the way of expected output (besides having a plain-text header and 512kb of some odd data).

If it weren't for the fact that the text in the header of the tune decompressed properly, I would think the Zlib inflate routine had been modified.

sreve

iTrader: (3)

if it does not let me know i should be able to fix it via email if its a bin.
see pdf

2002_Z28_Six_Speed

iTrader: (19)

I got that part covered. The button to fix the checksums in efilive is in a weird spot. Am working on getting a bin of my cos5 so I can try and enable lean cruise on it. Using efi live is alot easier than making a program to do the checksum yourself.

EFILive will only download PCMs into a .tun
I have been thinking about getting tunercats because there are several people in the area with 1997 vortecs that want tunes. This should also allow me to get a .bin of the cos5

Shon Herron

iTrader: (25)

Do the 97 vortecs have the tables you guys are trying to get to?
And still unsure why going thru this when you can do the same thing with alot less effort with the tables that are already there in the sw packages.....

ryansm1

iTrader: (8)

Because they aren't already there, or aren't enabled. This is the correct way of doing things. Using the OL fueling tables forces you to stay in open loop, which not everyone wants to do. Adjusting the switch points for the NBO2 to attain a more accurate value for stoich is fine, but tweaking them to read lean at certain CL-modes is fooling the PCM.

If we followed your logic, we would still be tuning by adjusting IFR values and leave everything else stock.

Shon Herron

iTrader: (25)

And the end result is what???

2002_Z28_Six_Speed

iTrader: (19)

Sorry my statement was ambigous. I needed Tunercats to pull .bins from cars because EFI Live will only do .tuns.

A couple of people in my area wants tunes on their 1997 vortecs. Not lean cruise tunes just regular fueling tunes. I thought I could charge them and then buy Tunercats with the money. Since EFI Live won't do their vehicles anyways.

Two birds with one stone.

ryansm1

iTrader: (8)

The end result is having a properly functioning car that doesn't use hacks to achieve similar results. If you want to do it the easy/hack way, that's fine (and will probably be about the same), but that's not what this thread is about.

hrodgmc

iTrader: (2)

BDM method of reflashing is already in use by a couple of tuning companies. Good luck buying tunercats obd2 now since jet bought it out.

Efilive was doing some vortecs.

Shon Herron

iTrader: (25)

So the professional tuners that have been doing it this way for a while now are hacks and in the end, the customer is happy b/c their H/C LSx is getting high 20's to 30 MPGs....
Good luck with it all and I hope it is worth it. Does seem cool to unlock it on the other platforms though....if this could be done with the LT1s the market would explode, might could convince me to buy what is needed....