AndyF
08-02-2009, 12:08 AM
Right then people,
Following on from my discussions with Mr Banks on his thread where I asked about linear transformations etc... I now believe I have the understanding of how the scales on the maps are interpreted by the ECU and therefore have a way of rescaling the load limits on the fuelling and ignition maps.
The way in which the ECU determines which cell it will look at is via one of the above mentioned linear transforms. Basically, this takes the form of a list of raw data values of the calculated airflow and which column in the table that value represents.
To try and put it into simpler terms, I'll give an example...
This is the output of the air volume transform that is used as the load scale on the ignition and timing maps
Raw value ---> column number
0 ---> 0
1 ---> 1
2 ---> 2
3 ---> 3
4 ---> 4
5 ---> 5
6 ---> 6
7 ---> 7
8 ---> 8
9 ---> 9
10 --> 10
11 --> 10.5
12 --> 11
13 --> 11.5
14 --> 12
15 --> 12.5
16 --> 13
17 --> 13.5
18 --> 14
19 --> 14.125
20 --> 14.25
21 --> 14.375
22 --> 14.5
23 --> 14.625
24 --> 14.75
25 --> 14.875
26 --> 15
27 --> 15
28 --> 15
29 --> 15
30 --> 15
Now the thing to try and get your head around is that each raw value will be the same size increase and so the increase in values between column numbers differs..
If in the above example, the raw values were psi (which they aren't but it's an example) then we would have the following column definitions in the map
column number ---> psi
0 ---> 0
1 ---> 1
2 ---> 2
3 ---> 3
4 ---> 4
5 ---> 5
6 ---> 6
7 ---> 7
8 ---> 8
9 ---> 9
10 --> 10
11 --> 12
12 --> 14
13 --> 16
14 --> 18
15 --> 26
so you can see that the scale isn't linear like it is on the later evos.
However, because I now understand the linear transforms and how they work (and where they are stored in the code) then we can rescale those values whichever way we like and have them read up to whatever 'load' values we like.
The only problem I have is that my car is off to the bodyshop for a week starting on Monday and so I won't get chance to see if I can alter the load scales (and therefore which cells get 'hit' in the maps) until the week after next but I'll update this thread if all is successful.
Andy
Following on from my discussions with Mr Banks on his thread where I asked about linear transformations etc... I now believe I have the understanding of how the scales on the maps are interpreted by the ECU and therefore have a way of rescaling the load limits on the fuelling and ignition maps.
The way in which the ECU determines which cell it will look at is via one of the above mentioned linear transforms. Basically, this takes the form of a list of raw data values of the calculated airflow and which column in the table that value represents.
To try and put it into simpler terms, I'll give an example...
This is the output of the air volume transform that is used as the load scale on the ignition and timing maps
Raw value ---> column number
0 ---> 0
1 ---> 1
2 ---> 2
3 ---> 3
4 ---> 4
5 ---> 5
6 ---> 6
7 ---> 7
8 ---> 8
9 ---> 9
10 --> 10
11 --> 10.5
12 --> 11
13 --> 11.5
14 --> 12
15 --> 12.5
16 --> 13
17 --> 13.5
18 --> 14
19 --> 14.125
20 --> 14.25
21 --> 14.375
22 --> 14.5
23 --> 14.625
24 --> 14.75
25 --> 14.875
26 --> 15
27 --> 15
28 --> 15
29 --> 15
30 --> 15
Now the thing to try and get your head around is that each raw value will be the same size increase and so the increase in values between column numbers differs..
If in the above example, the raw values were psi (which they aren't but it's an example) then we would have the following column definitions in the map
column number ---> psi
0 ---> 0
1 ---> 1
2 ---> 2
3 ---> 3
4 ---> 4
5 ---> 5
6 ---> 6
7 ---> 7
8 ---> 8
9 ---> 9
10 --> 10
11 --> 12
12 --> 14
13 --> 16
14 --> 18
15 --> 26
so you can see that the scale isn't linear like it is on the later evos.
However, because I now understand the linear transforms and how they work (and where they are stored in the code) then we can rescale those values whichever way we like and have them read up to whatever 'load' values we like.
The only problem I have is that my car is off to the bodyshop for a week starting on Monday and so I won't get chance to see if I can alter the load scales (and therefore which cells get 'hit' in the maps) until the week after next but I'll update this thread if all is successful.
Andy