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Hello. I already asked same question in another topic but see that this topic is more active.
I need to read, change and then write ACD firmware on Evo VIII. I have Tactrix OP2.0 and I want to ask - firmware in ACD can be protected or not? Can I read firmware without fear?
The ACD controller is MR580146.
Thanks!
Firmware is not protected.
Yes - read without fear!
From what I Have been using, A maps have been G force vs Speed (kilometers). G force would be 0.0 to 4.0 range which is the voltage used to determine the G force load.
Anything with ZERO is where the Delta between the front and rear axles will meet or are equal. Anything that is 1 or more (2,5,10,20) is the amount of degrees that the steering wheel will turn before both front and rear axles are equal. It will lock at that amount of degree input BUT only to be sure both axle become equal, Its NOT A FULL LOCK.
Example: at 2.6 volts or 0.1 G's, the steering wheel can be turned 2 degrees before it locks to be sure both axles are equal speed. As you decelerate harder to 3.0volts(0.5G), 3.7volts(1.2G), 5 degrees or even 20 degrees of steering input can be available. For that amount of degrees, it allows the wheels to be free. Power is free to go to the Front wheels (to pull) or free to go to the Rear(to push). If you Decelerate hard, there is very little weight at the Rear which can make the Rear wheels overpower the Front wheels(sometimes). So the ACD is OPEN longer to reduce Understeer and HOPE power gets delivered to the Rear!!!
On the STOCK Maps Tarmac is more Active then Gravel or Snow. In Gravel or Snow the ACD allows more Slips (Locks less frequently). On the Street, Gravel or Snow will allow the the car to be more Front Wheel Drive because the front tires make a Larger ARC while turning and the rear just drags and follows. Until the ACD starts to lock at 6 degrees or even 40 Degrees, the Rear matches the Front. At times, the Rear can overpower the Front. If the Rear overpowers the front (like with an upgraded REAR DIFF), it will take the same amount of steering degrees Input for the Rear to match the Front.
A Maps are Dominant and the condition will apply Unless B maps or C maps Say other wise.
The manufacture relied more on the A maps
B maps, C maps are limits
ALL other maps are Maximum Limits
For B maps
The B maps have been Throttle input vs Speed(kilometers).
Anything with a ZERO in the plot charts is Full Lock. Anything that is 100 or less is the amount of slip that is allowed.
Example: A Map will make sure the front and rear are equal at a steering Degree input.
B Map can still allow 100% slip AFTER A Map makes sure that both axles Match each others ARC (DELTA). B Map can allow 75% slip or 50% slip or 25% slip or 0% slip(NO SLIP)
If ALLLLL B Map is 0% slip OR FULLY LOCKED, YOU can have BIND also WEIRD and SCARY understeer or oversteer.
100% Slip is needed!!!! At the right time, speed, and condition then you can use 70, 50, 20, 0 slip, and that can be useful.
C map
Its speed vs Steering Degrees. 40 Degree increments.
A Map will do what it needs to do...
C map, if you steer to 40 Degrees or what ever degree is placed, it will allow 100% slip or what ever value is in the Plot.
Example: the row on the far left is "Steering Wheel Centered', then 40 degrees, then 80 degrees, etc.... as you steer away from "center" and approach 40 degrees, on STOCK it has 100% slip.
....OR you can have 50% slip or 10% slip. it can be 0% slip (Fully locked) as you TURN, get a little oversteer. YOU can give it power and then Unwind the steering back to "center".<<<< in the street that is fun.
...In Dirt that can give you understeer
....scary
So this is My 401702xml and ACD Map. To use my xml all other 401702xml can not be in the same folder. My 401702xml has to be by it self, even to see my ACD map and to understand my explanation and understanding of the ACD. I have been tuning ACDs for 3 years and tried a lot with and with out Rear Differential upgrades.
I hope we can add as many features as we can with other xmls and sources. Lets have this be as open source as possible and learn from each other. Ill throw some fully tuned roms on here once people can understand the possibilities as this opens up more.
hey guys, any one using the ra-C1 rom? how does it compare to other modded roms? on the road that is.
Opening that rom, I see T,G,S all have the same data! whats ur take on that!
hey guys, any one using the ra-C1 rom? how does it compare to other modded roms? on the road that is.
Opening that rom, I see T,G,S all have the same data! whats ur take on that!
The RA168749C1 ROM is terrible. There are slight differences between each setting, as it's designed for Dry Tarmac, Semi-Dry Tarmac and Wet Tarmac (T, G, S respectively). When i used to use that ECU years ago, i had most success on Gravel setting...but it's still terrible. I've even tried this ROM as a base to tune, and still don't like it as much as a stock ROM to modify (i find it still too twichy...maybe the time constants are too quick...don't know). On the road you probably won't notice too many bad effects, but on the track it's really bad as i said. Tuned stock ROM in my opinion is the way to go.
The RA168749C1 ROM is terrible. There are slight differences between each setting, as it's designed for Dry Tarmac, Semi-Dry Tarmac and Wet Tarmac (T, G, S respectively). When i used to use that ECU years ago, i had most success on Gravel setting...but it's still terrible. I've even tried this ROM as a base to tune, and still don't like it as much as a stock ROM to modify (i find it still too twichy...maybe the time constants are too quick...don't know). On the road you probably won't notice too many bad effects, but on the track it's really bad as i said. Tuned stock ROM in my opinion is the way to go.
what bad effects did u experience? Plan on trying it on a track some time in the future. But I still appreciate ur input if ur willing to further explain what u experienced.
what bad effects did u experience? Plan on trying it on a track some time in the future. But I still appreciate ur input if ur willing to further explain what u experienced.
I posted earlier in this thread about ill effects. Instability, twitchy, snap oversteer. It's terrible. Don't bother testing it...as the stock rom will be nicer to drive and you'll probably go faster on it. But as I said above, a tuned ROM is the way to go. Download Merlin's ROM on page 1 and go from there if you want to test something on track.
Short question:
In this thread there have been uploaded two files according the RalliArt K1 ACD ROM for EVO7 (= RA553831K1).
But both members aren't clear if their files are prope/correct K1 Files.
Has anybody double checked this or can anybody provide a checked K1 file?
Referring to a new theory of operation (seen here), here is an example of what I would change to achieve better turn in and less understeer on corner exit.
This is just a very quick mock up of a standard rom...no other changes have been made. In practice i would change many other aspects of the rom, but for targeting turn in and exit, this is what I'd change.
Change B and C table axis. These are both steering angle inputs. This change gives a finer control to smaller steering angles and allowing better "ramping" at smaller angles. I've found you generally don't want lockup at anything over 90 degrees steering wheel angle.
Change B and C table values. Values of ZERO will cancel the lockup from it's partner multiplication table. ie, A (throttle lockup) x B (steering angle). G (decel g-force lockup) x C (steering angle). Just remember the mathematical theory of 100x1 = 100, 100x0 = 0.
P map values (the big 9x36 table). Reducing the values in the 0 degree steering angle column will give a better turn in sensation as there's less resistance in the steering wheel. Expand it by slightly reducing the values in the 2nd column. Personally I don't like changing the values at high speed, as I think it makes the steering too twitchy, and at high speed i want stability.
I will reiterate that this is a just an example of changes (to an OEM rom) that can be made for demonstration purposes...the specific values have not been tested.
Referring to a new theory of operation (seen here), here is an example of what I would change to achieve better turn in and less understeer on corner exit.
This is just a very quick mock up of a standard rom...no other changes have been made. In practice i would change many other aspects of the rom, but for targeting turn in and exit, this is what I'd change.
Change B and C table axis. These are both steering angle inputs. This change gives a finer control to smaller steering angles and allowing better "ramping" at smaller angles. I've found you generally don't want lockup at anything over 90 degrees steering wheel angle.
Change C and C table values. Values of ZERO will cancel the lockup from it's partner multiplication table. ie, A (throttle lockup) x B (steering angle). G (decel g-force lockup) x C (steering angle). Just remember the mathematical theory of 100x1 = 100, 100x0 = 0.
P map values (the big 9x36 table). Reducing the values in the 0 degree steering angle column will give a better turn in sensation as there's less resistance in the steering wheel. Expand it by slightly reducing the values in the 2nd column. Personally I don't like changing the values at high speed, as I think it makes the steering too twitchy, and at high speed i want stability.
I will reiterate that this is a just an example of changes (to an OEM rom) that can be made for demonstration purposes...the specific values have not been tested.
where is the high speed portion in what you have above?
where is the high speed portion in what you have above?
The darker boxes around the values indicate values that have been "changed". In the example haven't changed anything above 131km/h on the P map.
NOTE - I've just changed my example picture in my post above. I uploaded the wrong one. The one posted now give a better example of "ramping" in the B and C tables.
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