Chop_Top

My 10,000 pound ride cruises about 60 MAP (give or take)

The Hiway mode spark curve ends at 50 MAP. Any code hackers know how to change this from 0-50 MAP to say, 20-70 MAP

funstick

ask the v8astrocaptian. he seems to knwo about these things.

V8Astro Captain

iTrader: (1)

Don't I feel special. I wish I could help but I'm only beginning to learn source code.

I think when a table ends like that the last value counts for everything higher. Meaning if the table value at 50 kPa is 5* SA for example, I think the ECM uses 5* for everything 50 kPa and up.

funstick

if theres a good commented hack of the code around id be willing to take a stab at it. im not a supercoder but a change like that shouldnt be to hard. ive got a good hex coder around so ill ask. got a good hack ?

Chop_Top

Thanx,I will have to try that then. I am not too sure how to tell if it is kicking in or not but maybe next week I will burn one with it in and one with out and see what happens.

Chop_Top

I don't know how good it is but you can find one at ECM GUY
747 hack

RBob

iTrader: (1)

'747, well why didn't you say so?! Makes a big difference in the answer. The hiway SA table is in vacuum, not pressure. So the 50 to 0 KPA VAC is close to 50 to 100 KPa of manifold pressure. Just that baro is taken into account.

RBob.

V8Astro Captain

iTrader: (1)

...he strikes back with another definitive answer...

Chop_Top

definitive answer??? So 50 is 50 and 0 is really 100. Hmmm sounds like Al Gore's fuzzy math..
I guess this means 70MAP is really 30 KPAVAC for this scale?
I find it hard to understand why the engineers would stray from the established MAP scale used for all other calculations.

funstick

its not the engineers its the people writing the hack and the ecu files. they could just make all values in standard of metric and stop the nightmare. im looking thorugh the code i dont have an answer yet. give me a few more days.im not a super programmer or anything.

RBob

iTrader: (1)

Your kidding right? The folks that wrote the hac? A hac is a reverse engineering of the original code. Kpa is Kpa is metric. Not the hac writers fault that the software spec defined the hiway SA table to be in vacuum. Yes, the software spec that the code engineers developed to in step for that mask. Jeez, that is the hiway SA table definition. That is how it is implemented within the ECM code. We don't make this stuff up.

RBob.

funstick

Rrob it could be done quiet simply to just bring everything to either kpa or vacum. create a standard. its long overdue do you think the engineers really worked in this many formats.?? i doubt it the original code was all done in metric im sure. its not any one particular persons fualt. over time many people working in there own prefered maesuring systems contributed and no one ever stopped to standardized all the amounts. its not a big deal maybe one day down the road someone will go through all the tdf's and ECU files and modifiy them.

in short MAP voltage is still 0-5 volts regardless of the scale.and the ECM doenst say oh *** ive got 50 kpa 5inch of HG. no its see's 2.5 volts. or a hex value of 128 after the a/d converter.
the scales are our own not the ECM's.

Grim Reaper

RBob brings up a good point also, 0 Vac IS NOT the same as 100 Kpa. You can have 0 Vac anytime you are in WOT (actually not truly 0 vac because you can't obtain a perfect vacuum).

However, you will only obtain 100 KPA at WOT at Sea Level. If you are at 1,500 feet, you will only read 95-97 Kpa @ WOT. And if you have boost, you can obtain 100 KPA (or more) at part-throttle at a lot of elevations.

But the point is 0 VAC is not the same as 100 Kpa.

funstick

please define how you are reaching zero vac does not equal 100kpa ?? im a bit lost ?.

for instance at 5V at the map ouput

0 vac equals atomoshpere. @ sea level (or 14.7 psi static)
100 kpa equals atmoshpere @sea level

just a bit confused about the statement please define how you are arrving at your pressure scales. thanx glenn.

RBob

iTrader: (1)

Manifold vacuum is gauge pressure, manifold pressure is in absolute pressure.

Funstick, have you ever put your hands & eyes on original GM source code?

RBob.

Chop_Top

Sooo.... For the definition of the HiWay Spark Mode, would the following chart be true? If my Heavy Chevy cruises at about 70 map I would add a few degrees advance at 70 map, being the 30 mark in the Hiway Spark Mode array?


------------------MAP----IN Hg
Full Vacuum............0____29.9
..........................10____26.91
..........................20____23.92
..........................30____20.93____Hi Spk Mode
..........................40____17.94_____KPA Vac
..........................50____14.94_____50
..........................60____11.96_____40
..........................70_____8.97_____30
..........................80_____5.98_____20
..........................90_____2.99_____10
No Vacuum..........100_____0________0

RBob

iTrader: (1)

The relationship shown above will be true as long as baro is at 100 KPa. As you increase in elevation the baro will decrease. Hence the above relationship will shift.

IE: If baro is 90 KPa (absolute pressure) then a manifold vacuum reading of 0 (gauge pressure) will be the same as 90 KPa manifold pressure.

As it is don't worry about that part (too much). As long as key on engine off MAP is ~ 100 KPa the above relationship holds true and you will get the intended results.

RBob.

funstick

------------------MAP----IN Hg volts
Full Vacuum..........0____29.9 0.0
..........................10____26.91 0.5
..........................20____23.92 1.0
..........................30____20.93____Hi Spk Mode 1.5
..........................40____17.94_____KPA 2.0
..........................50____14.94_____50 2.5
..........................60____11.96_____60 3.0
..........................70_____8.97_____70 3.5
..........................80_____5.98_____80 4.0
..........................90_____2.99_____90 4.5
No Vacuum.......100_____0______100 5.0

but couldnt this be true as well ? i think its only perception

Chop_Top

I gotta think so...
Aren't the Volts just what the computer sees from the map sensor? This whole process starts there and goes to the right.
Volts would be just 2/3 the way to machine language for MAP.
SOOOOOoooo....
somewhere there is another chart that goes
kpa=volts= 0-255 =#$%^&*

funstick

thats what i was trying to get at. the issue of perception is whats key here . exactly what is the value range the ecm uses for higway spark. i doubt it actually uses it over 50kpa. id bet it really uses the 20-50 kpa range. so what needs to happen in the code is the threshold disable value needs to be moved up.and the total range needs to be moved. im not really sure how to accomplish this just yet but give me a few more days ill figure something out.

Chop_Top

Funstick, If the above charts are correct everything is lovely! My machine has never seen lower than 50 map. This is no 3000 pound gen 3 I am dealing with, I got 10,000 pounds of sheet metal to push around and I don't think it could hit 40 MAP coming down a mountain 70 mph in low gear!

I have to try out the hiway spark, Ill take a coupla chips on a trip and see how it goes...

funstick

ok if you need to play with the scaler look at line e810 of the 747 hack you linked me to. ive gotta look at teh code for a while to see if theres anything there i think its in the masked rom looking at the adress however.

Chop_Top

WOW most of that one went right over my head, must be why I was looking for help.
I will snoop around that address but have no idea what I am looking for.

Chop_Top

Ok I looked at it and still have NO IDEA what it means

funstick

ok i looked at the hack a bit more. the values are in kpa NO vacum. that means that highway spark mode is only enabled from 0-50 kpa period no exceptions. if your map sensor is showing 60kpa you will be outside the range of the highway spark mode. now the way to adress this is to change the the scaler of the highway spark table. im not sure how to do this just yet but give me a bit of time ill figure it out. also to note the ecu file for winbin will need to be update to reflect this change. good luck i hope this answers your questions. the brackets denot on the chart below where the highway spark mode is active.


------------------MAP----IN Hg .........................................volts
Full Vacuum..........0____29.9.................................{h}...... 0.0
..........................10____26.91................................{h}...... 0.5
..........................20____23.92 ...............................{h}.......1.0
..........................30____20.93____Hi Spk Mode.....{h}...... 1.5
..........................40____17.94_____KPA ...............{h}.......2.0
..........................50____14.94_____50..................{h}...... 2.5
..........................60____11.96_____60......................... 3.0
..........................70_____8.97_____70......................... 3.5
..........................80_____5.98_____80......................... 4.0
..........................90_____2.99_____90......................... 4.5
No Vacuum.......100_____0______ 100........................ 5.0

Chop_Top

Well so much for hiway spark, It sounded like a good idea...

RBob

iTrader: (1)

Why do you say that?

RBob.

32V_DOHC

;---------------------------------------------
; HIWAY SPK ADV vs VACUUM
;
; ADDED SPK IF IN HIWAY MODE
; (See D024 & D025 FOR QUAL'S)
;
; VAL = SPK ADV * (256/90)
;---------------------------------------------
ORG $0D57 ; Spk Vac Kpa
;---------------------------------
LD157 FCB 0 ; 0 50
LD158 FCB 0 ; 0 40
LD159 FCB 0 ; 0 30
LD15A FCB 0 ; 0 20
LD15B FCB 0 ; 0 10
LD15C FCB 0 ; 0 0
;----------------------------------------------


For this we need to look at where vacuum comes from. Here we have vacuum = inverse( (baro - map) * 151 * 2). So if you look at baro = to $FF and map = to $E0 working through the math you get vacuum = $DB (219)

-----------------------------------------------------------
E584: LDAA L00FE ; BARO PRESSURE
E586: SUBA L002C ; MAP, Kpa
E588: BHI LE58D ; BR IF BARO GT MAP
; ... else
E58A: LDAA #1 ; PREVENT MAP ROLL OVER
E58C: CLC ; CLR CY
E58D: LE58D JSR LFC1C ;
E590: NEGA ; INVERT
E591: STAA L0031 ; VACUUM

-----------------------------------------------------------
FC1C: LFC1C BCC LFC20 ; BR IF
; .... else
FC1E: CLRA
; ... else
FC1F: RTS
FC20: LFC20 MUL
FC21: ASLD ; N x 2
FC22: BCS LFC2A ; BR IF OVERFLOW
; ... else
FC24: TSTB ;
FC25: BPL LFC2C ; EXIT & RETURN
; ... else
FC27: INCA ;
FC28: BNE LFC2C ; BR IF NZ
; ... else
FC2A: LFC2A LDAA #255 ; FORCE MAX VALUE
FC2C: LFC2C RTS

Below we see how the table is set up the A value is actually 1/2 vacuum. So with the numbers from before the A value into the 2D routine is $DB/2 or $6D (109). The B value going to the 2d routine is 48 ($30)

E810: LE810 LDAA L0031 ; VACUUM
E812: LSRA ; VAC/2 FOR LK UP SCALEING
;
E813: LDAB #48 ; LK UP ARG LIMITER, (50 Kpa VAC)
;
E815: LDX #$D157 ; HIWAY SPK ADV vs VACUUM, (6 LINES)
;
E818: JSR LFB45 ; 2d LOOK UP ROUTINE

Here our B value is subtrated from our A value. The result is A for 2d lookup = $6D from above - $30 Lkup limiter = $3D. The new A value is multiplied by $10 and look up proceeds to interpolate between the thrid and fourth row. The values for the table are 0 Kpa vacuum to 50 Kpa vacuum or with a Baro of 100 Kpa you would use a Map range of 50 to 100 Kpa.

;--------------------------------------------------
; 2d LOOK UP FUNCTION
;
; MAY HAVE A LOOK UP ARGUMENT LIMITER IN B Reg.
;--------------------------------------------------
FB45: LFB45 SBA ; A - B (LIMIT - Lk up Arg)
FB46: BCC LFB49 ; 2d LOOK UP ROUTINE IF B GT A
; ... else
FB48: CLRA ; CLEAR A, ZERO OUT LK UP ARG
;--------------------------------------------------
;--------------------------------------------------
; 2d LOOK UP FUNCTION
; WORKS W/ASCENDING or DECENDING TABLES
;
; ENTER WITH:
; X REG POINTING TO 2d TABLE
; A Reg = LOOK UP VAR
;
; EXIT WITH:
; A Reg.
; RESULT IN L0051 (TEMP BUFFER)
;
; Result is interp'ed in 1/16's
FB49: LFB49 LDAB #16 ;
FB4B: LFB4B MUL ; LOOK UP ARG x 16
FB4C: PSHB ; SAVE QUOTIENT LSB
FB4D: TAB ; MSB OF LK UP VAR x16 TO B REG
FB4E: ABX ; ADJUST INDEX W/B Reg
FB4F: LDD 0,X ; GET 2 TABLE VALUES
FB51: LFB51 STAA L0051 ; SAVE LOWER TABLE VALUE IN L0051 (1 OF 2)
FB53: SBA ; SUB LOWER FROM UPPER TABLE VALUE
FB54: PULB ; GET LSB OF LOOK UP ARG x 16
FB55: BCS LFB60 ; BR IF UPPER - LOWER = NEGITIVE..
; ... else


HTH

John

funstick

this is an error in the hack. most likely a typo. its KPA not KPA vacum. the table is not inevrse it was simply miss interpreted by however wrote the hac. could you imagine the detonation nightmare that would occur if the engine were exposed to an addition 3-4 degress of timing at WOT. ???yet again a mere oversight by whoever wrote the hac ?? and baro only factors into the scalling at start up. once running the ecm decides what voltage equals what map output is based on the initial key on engine off baro reading. this would only affect you at high elevtaions but then again the ecm is compenstating for this with the intial baro reading. if you doubt my comclusions put the highway spark values in and watch it via a scanner. at anything over the ecms scalled 50kpa map reading the timing will drop off at whatever the added highway spark mode is.

Chop_Top

Oh No!
I Can't thank you guys enough for your help in looking in to this for me. But now I start looking like a real dumb a** here. I have been looking at this with winALDL which works flawlessly for me but I don' t remember it spitting out the timming numbers being called for.
How can I scan the timing the computer is calling for. I don't know any one fast enough to run along side my ride with a timing light....

32V_DOHC

this is an error in the hack

Show it to me. I have traced from the a/d port to the table. If I plug in 0 KPA of vacuum I get 5th row(a value of $04 with $00 being row 1) and a remained of $F0 Basicly all the way to the 0 KPA of vacuum on the table. If I plug in 50 KPA of vacuum I get 1st row with no remainder. I have worked the math for every row and it checks out perfectly. Have you checked your math?

could you imagine the detonation nightmare that would occur if the engine were exposed to an addition 3-4 degress of timing at WOT. ???yet again a mere oversight by whoever wrote the hac

The hac is what is there. I am reading the code that was spit from the disassembler not the comments. You are trying to make the code fit the way you think by saying that it is wrong. Dig a little deeper into the hac.

FWIW the reason there is a value for 0 vacuum is so that a 0 can be put in that place in the table. That way if the engine goes into highway mode at high pressure the value added is zero.

John

RBob

iTrader: (1)

You will need to use a hex editor on your bin. Change location $4E7 to $00, $4E8 to $66, $4E9 to $00 and $4EA to $67.

Now on the scanner the PROMId will be the timing. To convert it to degrees multiply the PROMId value by .352 and add in the inital (base) timing. So if the PROMId is displaying 114 the actual timing is 114 * .352 = 40 deg + the initial.

The initial is what the distributor/prom is set to (typically between 0 and 6 degrees). If you are not sure of intital/base see the paper on the GMECM site about a spark only '747 setup. It covers the '747 timing. Questions, just ask.

RBob.

Chop_Top

GREAT! I am off to make the change. My dist and the prom are set to 6*
I gotta try this out tonight!

Chop_Top

I forgot who wrote WinALDL, (A hero) but maybe we can get him to add this to the dash and recording.

Chop_Top

Fantastic! All I can say is Fantastic!
I can now see my timing! This patch should be in the "sticky" introduction to prom burning...
Thanx,

RBob

iTrader: (1)

Chop Top, you are welcome. 32V_DOHC (John) I'd like to thank you for your input. I was starting to reach for the ceiling. . .

RBob.

hectorsn

serenity now...serenity now...serenity now....

Come now Bob, we can't have you going mad!

Chop_Top

Ok here is the latest hubub.
Thanx to Rbobs code mod I have been able to see the timing. I have been making changes to the timing all day. Each time I made two chips, one chip with 5* HyWay SA (in all cells) and one with out any Hyway SA at all. Looking at the spark advance reported through WinAlDL There was no differance between the two chips.

I am still running well above the 50MAP level at cruise so the table must be 0-50 MAP for HYway spark????...

With the timing I added today, I did get MAP at 60MPH down to about 62MAP from 67MAP and the TPS dropped from about 26 to 23%. This has gotta be worth a teaspoon of gas or two.

JPrevost

I thought it was common knowledge by now that you could modify the aldl stream to spit out timing. I use it for lots of other things too like sync and async injector pulse widths, o2 x-counts (not in the 8746 ecm by default), desired idle speed, tps% away from idle control, desired AFR, AFR vs coolant in open loop, and injector constant.
I just wish this bloody ecm had a faster rate. When it does it's going to be awesome. Datalog and change anything and everything.

RBob

iTrader: (1)

There are 3 quals before HiWay SA will be enabled. At $024 and $025 in the bin are min MPH and timer delay quals. The 3rd and last qual is the ever so elusive forced knock test.

Until the forced knock test has been successfully completed HiWay mode and PE SA will _not_ be applied. There is a patch to bypass this and set the forced knock test as completed. See diy-efi incoming for it (747_esc.zip? esc_done.zip, something like that).

RBob.

jwscab

Yep, we just tried that patch in my brother's regal, and that force knock test is no more. Thanks for the help with that Rbob, it makes the car alot easier to drive while merging....and keeps the kid from beating the car into the ground. I'll have to play around with that timing change to see exactly whats going on in that motor.

Chop_Top

Ok I found the patch and will try it out.
But surely there is someone out there that knows from experience (not by trying to read the code) when and at what MAP values the HyWay Spark kicks in at... I hate to beat myself up trying to make this thing work if it only works below 50 MAP.

Chop_Top

I ran the Knock test patch and just for information here is what looks like changed
------------NEW......WAS
$0BD6..........0A.........21
$0BD7..........8A.........B1
$0BD8..........80.........D2
$0BD9..........97.........CA
$0BDA..........0A.........22
$0BDB..........20.........16
$0BDC..........12.........B1

Now I gotta get it in the yacht and see if it will work make any diff.

RBob

iTrader: (1)

Tried it out on the bench, it works. The MPH qual is in MPH/3.2. So a 96 is 30 MPH. The timer is in seconds. So a 40 is 40 seconds. Then the actual hiway SA table is relative to baro & map (hence vacuum).

Unless you can hold a steady map, check baro before startup, and add enough SA it may be difficult to verify while on a roll.

Just give it some time and you'll see it in action. To help see it you may want to flatten an area of the normal SA table. It will make it easier to see hiway SA invoked.

RBob.

Chop_Top

You tried it on the bench and it kicked it where? 50 - 100MAP?
I had added 5* at all cells and did not see any extra advance at all. I checked several "steady " MAP areas and they followed the SA chart as Tuner Cat shows it. ( WinBin does a little math thing that is confusing)
It is possable I did not pass the Knock test but I have a new sensor that does appear to work. I get knocks as I advance too far.

What do you mean "check baro"?

RBob

iTrader: (1)

I added timing at 20Kpa VAC (only). At 80 Kpa MAP ~ 70% of that timing was added, baro was at 104 KPa. (I should have bumped up the MAP to 84 to check for full timing, I was tired).

As this was a stock bin I hit the knock button to set the forced knock test as OK. Coolant was at 80c, closed loop, 3000 rpm, just set things up like the vehicle was cruising on a hiway.

At 70 Kpa MAP there was no added timing which is correct. Dropping below the 30 mph threshold and the timing was removed. Once above the mph threshold the timer delay was again in play.

Check baro by turning on the ignition (engine not running) and read the MAP on a scanner. That will be the initial baro value. Baro will be adjusted with a pseudo baro reads whenever at lower RPMs and high TPS.

RBob.

Chop_Top

IT WORKS!!! IT WORKS!!! YEAaaa....

Thank you Rbob, Funstick,32V_DOHC, Astro Captain, and everyone else, for your continuing support. I now have the HyWay Spark working.
I made two proms with the flat 30* timing in the whole area I normally run at. One of them I added the Knock patch.
I started out with the one that did not have the patch. It did not seem to do anything. BUT I slowed down below 30 mph for another car and when I sped up again it worked.
It looks like I have to go through the 30 mph twice the first time.

Also Once started It always there no mater what you do with the TPS / MAP until you drop below 30mph again.

I changed to 45 MPH on the one I am using and it too seems to want to see 45 MPH twice. Maybe Rbob can conferm this on the bench???

Never did have to use the one with the Knock Patch.

Again Thanx!

Now on to new endevors, how to PROPERLY set timing. for this heavy thing.

funstick

hmm wel it looks like is get to eat some face. oh well. i will have to change a 747 ecu file to accurately display the easier map reading for highway sprk mode. Rrob how are you at embeded code ???? kind of startng to work on a handheld scanner using a sega gamegear ?

oh and chop top what the various MAP readings ?? where the highway spark mode is engagin and disengaging.

RBob

iTrader: (1)

Your welcome, glad to hear that you have it operational. I'll check the twice over the MPH limit. Doesn't sound right. Maybe the forced knock test finally passed when you accelerated again.

As you noticed the HiWay SA is there until you drop below the MPH thres. Just be sure to keep the 0 VAC SA value small to prevent knock under heavy load.

RBob.

Chop_Top

When I uploaded my downlinker from the Black Box Flight Data recorder, I could tell right where the HyWay mode kicked in. At first I couldn't understand why I wasn't getting the full 4 degrees I had requested but when I went back to WinBin I see I only put in a raw value of 4 which is 1.4 degrees.
As far as engaging and disengaging, I don't have a wide enough group of MAP readings but of the several tries I have made it seems to follow the 50= 50 MAP...0= 100 MAP discussed earlier.