Highway Mode min speed constant
05-05-2004, 12:16 PM
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Car: Devastating Droptop
Engine: 355 Supercharged
Transmission: Auto 4L60, Built for 700hp
Highway Mode min speed constant
7730, AUJP
I remember reading somewhere on this board, that somebody
changed the Constant from Min speed to Max speed for
Highway mode fueling enable.
I would like to make the change so that Highway Mode disables
above a certain MPH or RPM.
I remember reading somewhere on this board, that somebody
changed the Constant from Min speed to Max speed for
Highway mode fueling enable.
I would like to make the change so that Highway Mode disables
above a certain MPH or RPM.
05-05-2004, 01:01 PM
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Car: 91 GTA, 91 Formula, 89 TTA
Engine: all 225+ RWHP
Transmission: all OD
Axle/Gears: Always the good ones
do a search for highway spark/fuel modes made originally by Glenn..
ONe of his posts or replies lists all pertinent data to change the actual code so highway spark and fuel work better (almost all changes are spark related)
later
Jeremy
ONe of his posts or replies lists all pertinent data to change the actual code so highway spark and fuel work better (almost all changes are spark related)
later
Jeremy
05-06-2004, 11:09 AM
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Car: Devastating Droptop
Engine: 355 Supercharged
Transmission: Auto 4L60, Built for 700hp
Ok, I found this that glenn posted to one of my old post.
I implemented the changes today and it works great.
Now I wounder if we could do the same for the Highway mode Fueling, it would be nice to get out of this mode at an specified RPM like the Highway mode Spark.
I implemented the changes today and it works great.
Now I wounder if we could do the same for the Highway mode Fueling, it would be nice to get out of this mode at an specified RPM like the Highway mode Spark.
Originally posted by Glenn91L98GTA
Here are the following Hex Codes I substituted to make Highway Mode Spark Advance work. You will need a Hex Editor (Edit function of Windows Version of Pocket Programmer works fine too, if you read the file with TunerCat to get the Check Sum right).
The following changes to the hex address in the eprom will: 1) Change the Gear Test (which is the test that doesn't work properly IIRC) and changes it so Highway Mode Spark Advance now tests to see if you are travelling > 40 mph (and you meet the MAP Load and Coolant Temp tests). 2) It will change the RPM test from a "Minimum" to a "Maximum". This will avoid having Highway Mode being invoked while you are in PE (which is possible with the stock routine).
If you wish to alter the speed from 40 mph to something else, just change:
x'Addr 3987 from x'28 (d40 for 40 mph) to whatever speed you want (converted into hex, like 50 mph = x'32.
x'Addr x'old/d'old x'new/d'new
------ --------- ------------
x'3984 x'B6/d'182 x'96/d'150
x'3985 x'01/d'001 x'81/d'129
x'3986 x'40/d'064 x'81/d'129
x'3987 x'B1/d'177 x'28/d'040 <---(MPH limit)
x'3988 x'82/d'130 x'22/d'034
x'3989 x'FE/d'254 x'02/d'002
x'398A x'22/d'034 x'20/d'032
+
x'399F x'25/d'037 x'22/d'034
+
x'39A6 x'22/d'034 x'20/d'032
The stock GM routine does not work and even if it did, it works poorly. The above changes to the instructions will make it work better.
PS: The RPM calc is incorrect. It does not follow the conventional RPM calculation. I found using the "coventional calc" for 2,400 rpm yielded a cut-off of 3,000 rpm. I much prefer the RPM being a max constraint than a minimum constraint. I think it's a dumb idea to allow the HMSA to work at very high rpms.
[This message has been edited by Glenn91L98GTA (edited November 02, 2001).]
Here are the following Hex Codes I substituted to make Highway Mode Spark Advance work. You will need a Hex Editor (Edit function of Windows Version of Pocket Programmer works fine too, if you read the file with TunerCat to get the Check Sum right).
The following changes to the hex address in the eprom will: 1) Change the Gear Test (which is the test that doesn't work properly IIRC) and changes it so Highway Mode Spark Advance now tests to see if you are travelling > 40 mph (and you meet the MAP Load and Coolant Temp tests). 2) It will change the RPM test from a "Minimum" to a "Maximum". This will avoid having Highway Mode being invoked while you are in PE (which is possible with the stock routine).
If you wish to alter the speed from 40 mph to something else, just change:
x'Addr 3987 from x'28 (d40 for 40 mph) to whatever speed you want (converted into hex, like 50 mph = x'32.
x'Addr x'old/d'old x'new/d'new
------ --------- ------------
x'3984 x'B6/d'182 x'96/d'150
x'3985 x'01/d'001 x'81/d'129
x'3986 x'40/d'064 x'81/d'129
x'3987 x'B1/d'177 x'28/d'040 <---(MPH limit)
x'3988 x'82/d'130 x'22/d'034
x'3989 x'FE/d'254 x'02/d'002
x'398A x'22/d'034 x'20/d'032
+
x'399F x'25/d'037 x'22/d'034
+
x'39A6 x'22/d'034 x'20/d'032
The stock GM routine does not work and even if it did, it works poorly. The above changes to the instructions will make it work better.
PS: The RPM calc is incorrect. It does not follow the conventional RPM calculation. I found using the "coventional calc" for 2,400 rpm yielded a cut-off of 3,000 rpm. I much prefer the RPM being a max constraint than a minimum constraint. I think it's a dumb idea to allow the HMSA to work at very high rpms.
[This message has been edited by Glenn91L98GTA (edited November 02, 2001).]
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