John Millican

iTrader: (1)

My friend has a '91 Corvette. He has a spare chip and asked me if I'd lower his fan temp. I said "shouldn't be a problem". His prom is a AXCR on the sticker. I am assuming it's a speed density since it's from a '91 car. I pulled the BIN from the chip and was able to read it with TunerCat $8D. I was shocked at what I saw! The spark tables were through the roof! Wow, talk about aggressive. I am still in shock.

My question is AXCR isn't listed in the Ultimate BIN Library under the '730 ECM. Why or why not?

Second, would this be a better "base" prom to start with for speed density then the AUJP?

Lastly, I erased it for 30 min and tried to "program device" with PP and it replied "device did not verify to buffer". I repeated trying to write over it several times and still it does not verify. I put is back into the UV light for 1 1/2 hours and it does the same thing. I am using PP proper, I have burned MANY proms but mine use a ZIF socket and I erase and burn JUST the EPROM, not the whole memcal.

nsimmons

what i can tell you is i used to own a 91 vette with the same axcr bin, the spark is very aggresive, and i needed to run 94 to take full advantage. Also the vettes ecm is the 7727 not the 7730, as its an underhood version, that may explain why its not listed.

89 Iroc Z

1 1/2 hours of erase time is too much. You can over erase EPROM and damage them.

John Millican

iTrader: (1)

I agree it's a long time but SOME proms do take that long, especially when it's still in the memcal and doesn't fit quite right in the eraser.

John Millican

iTrader: (1)

I looked and the AXCR isn't listed in the Ultimate BIN Library under the '727 ECM either.

How is it that this BIN has a VERY radical spark table? Can I use this BIN as a base for a speed density engine and then tune from there?

SMasterson

http://holman.cs.uml.edu/~sdurphey/b...b.cgi?BCC=AXCR

BCC= AXCR9819 Scan id= 9831 Part number= 16159800
Release date= 10/18/90 Engine size= 5.7 Trans Type= Auto trans
ECM/PCM: ECM #01227727

Used in cars:Chevy
Possibly used in:CORVETTE/CONV CORVETTE ZR1

Options:
With GM1 AXLE, REAR, 2.59 RATIO

With L98 5.7L GAS 8 CYL MFI

According to this page http://www.cruzers.com/~ludis/p4xref.html#1227727 the PROM could be either a 27c128 OR a 27c256 although I don't they got all that code crammed into the 128 for the V8 TPI engine. Maybe the V6's listed. Or they didn't have the information available when that was posted.

I'd like to see a copy of that bin file myself!

kevinc

John- I emailed you offline, disregard. I did some digging and found the AXCR is auto trans, but I did find AXCN which is 5.7L manual trans. I used TunerCat's demo binary compare util and found >12,000 differences between AXCN and ARFP (5.7L, manual trans) which I've been using as a base...hmmm...

The diffs are all over the place, down in the settings area and way up in the program area. I may copy my current VE and spark tables into an AXCN and give it a try this weekend.

John Millican

iTrader: (1)

How'd it go this weekend Kevin? I am very interested to see if the AXCR is a better base to start tuning from instead of the ARFP.

For those of you who never seen a AXCR BIN, here you go. Check out the spark tables!

This is a NEW fixed attachment!!!!

TRAXION

FWIW - I like these spark tables as a base for high performance applications where the car is seriously modded with a big cam and a big stall. I started using these spark tables as a base over a year ago when I decided to redo my spark calibrations. They made a very nice difference right away in terms of part throttle driveability ... specially cause I have a 3600 stall. Definitely much better than the AUJP for my application. My spark tables are still similar to these and I run 10d base timing. At some points in my part throttle curve I am running over 50d of timing. Just depends on what your application needs. More timing is not always a good thing ... but my car loves timing in the part throttle area to get it moving. Its much more responsive because of it.

Tim

John Millican

iTrader: (1)

OK Traxion, thanks for the input. Did you use the entire AXCR bin or just the spark tables as a base?

kevinc

I dumped my VE, PE, accel enrichment, and other mods from my current AFRP bin into AXCN (not AXCR which is for an auto trans application, AXCN is for manual trans) and took a test spin. It corrected an annoying exhaust pop (mini backfire) I was seeing during shifting (sudden decel, too quick for DFCO to kick in) and that's about it thus far.

Even if that's all I get out of it, it was worth the effort as the popping during shifting was kinda *******.

AXCN ('91) is newer microcode than ARFP ('90) and using TunerCat's binary compare util there are >200 differences from location 03000 on up in the program area, so I'm presuming GM made some improvements in the overall program. Seems best to be running the latest microcode for the platform anyway.

Thanks John Millican for the idea! AXCN is my new binary base going forward.

TRAXION

I used AUJP but ported over the spark tables. I didn't want to complicate anything by using a corvette bin in my f-body (oil temp, etc.).

Tim

John Millican

iTrader: (1)

Urgent!!!

Anyone that tried and copied the AXCR.BIN I posted in this post, the file is corrupt. Here is a CLEAN copy.

The first copy I scanned off his DAMAGED prom. I have tested this new bin i got from his NEW replacement prom.

RedIrocZ-28

Can anyone give me some info on this Corvette bin I have? Its ABTF out of an 87 Corvette. My car picked up 2 mph with this chip and it was still running crappy. It pulls like a raped ape though when installed. The driveability sucks though. Anyone have a clue what this EPROM came from? (Auto/Manual blah blah blah?)

I couldn't find it in the list.

John Millican

iTrader: (1)

BCC used in 1987. (Scroll down for more info)
BCC= ABTF0735 Scan id= 7771 Part number= 16070733
Release date= 06/02/86 Engine size= 5.7 Trans Type= Auto trans
ECM/PCM: ECM #01227165

Used in cars:Chevy
Possibly used in:CORVETTE

Options:
With L98 5.7L GAS 8 CYL MFI

With MD8 AUTO 4 SPD THM 700 R4

With NA5 FEDERAL REQUIREMENTS

With NM5 EMISSION SYSTEM, NON-CLOSED LOOP (CANADA)

Without VB4 PROVISION OPTIONS, GULF STATES ORGANIZATION (EXPORT)

Without VD1 PROVISION OPTIONS, EUROPE (EXPORT)

Without VE1 PROVISION OPTIONS, JAPAN (EXPORT)

Without VT7 PROVISION OPTIONS, UNREGULATED COUNTRIES (EXPORT)

Grumpy

Please don't be surprised when you knock the ring lands off a motor playing some of these games.

If you want to cut+paste selected tables from one bin to another, your just playing with fire.
The reason the AUJP, and ARAP bins are suggested is that they are a good starting point, and they match the current HACs.
GM does make changes in the code areas from time to time, and they can be serious.
Don't assume!!!!!!!!.
Taking short cuts into the unknown will burn you.

Timing is just 1/2 the issue, it must match the fuel curve. So unless you know the fuel is there, you can be running at say Tip-In detonation, and never know it till you hear a rod knock.

Start with a known good base that matches the code, and then build on that. You want to try some elements of different table fine, so that, but realise when you go en'mass you might not like the answer.

SATURN5

Wouldn't this be because the vette has aluminum heads verses a F-body with cast iron heads? cheers, Bob

kevinc

Great point Bruce, and just to clarify what I stated about "copying my VE and spark tables" there's detail missing there. I regard the VE, Power Enrichment Fuel, Pwr Enrich Spark, Accel Enrichment, and main spark tables all to be a matched set after tuning. Mixing and matching between bins is, as Bruce said, a bad idea.

My purpose in copying these tables from bin to bin is to leverage the improvements in the program itself, and I scan the snot out of the car afterward looking for signs of trouble like spark knock/retard, BLMs out of whack, spark advance not matching up with what's in the table.

Take a super-hot spark table like ARAP and drop it into a standard F-body bin, you'll be doing an engine swap soon.

craiger

I understand what Bruce is saying. I am glad that bruce posted what a performance timming table is supposed to look like and also the Vett Bin posted. This gives me and others something to compare our tables with. From these two things, we can look at our starting point and use the given information as a compas to the right direction. TO copy and paste defeats teh purpose of this board. We are hear to learn how to burn our chips for the proper tune and to get teh best performance out of our cars. If you copy a bin and use it, that's your biz, but just realize that every car is different and to get the perfect tune, we all need a good compass but to copy and paste could have huge consequences........