Maps

From the above it can be seen that the eproms are not interchangeable between ecu types.

 

Maps/Data EPROM locations

L1 Address	L6 Address	L8 Address	P8 Address	Bytes	Inj or Ign	Description
FA90	FA94	F800	8800	32	Injection	Fuel map RPM header
FAB0	FAB4	F820	8820	32	Injection	Fuel map MAP header
FAD0	FAD4	F840	8840	208	Injection	Fuel map table 16x13 (P8 = 256bytes 16x16)
FBA0	FBA4	F910	87C0	16	Injection	Vbatt correction
FBB0	FBB4	F920	8950	16	Injection	Warm up enrichment correction
FBC0	FBC4			16	Injection
		F930		16	Injection
FBD0	FBD4	F940	8980	16	Injection	Cranking decay enrichment Map ECT header
FBE0	FBE4	F950	8970	16	Injection	Cranking decay enrichment Map time header
FBF0	FBF4	F960	8990	64	Injection	Cranking decay enrichment Map table 8x8
FC30	FC34	F9A0		16	Injection	WOT enrichment
FC40	FC44	F9B0	8C60	8	Injection	Fuel cut Re-enable RPM
FC48	FC4C	F9B8	8C68	8	Injection	Fuel cut RPM
FC50	FC54	F9C0	8A70	16	Injection	Injector start point phasing v RPM
FC60	FC64	F9D0	8A80	16		ACT calibration
FC70	FC74	F9E0	8A90	16		ECT calibration
FC80	FC84	F9F0	8AA0	32	Ignition	Ign map RPM header
FCA0	FCA4	FA10	8AC0	16	Ignition	Ign map MAP header
FCB0	FCB4	FA20	8AE0	128	Ignition	Ign map table 16x8 (P8 = 160bytes 16x10)
FD42	FD46	FAB2	8CD6	2	Injection	Rev limit - Hard cut
FD44	FD48	FAB4	8CD8	2	Injection	Rev limit - Soft cut
FD64	FD68	FAD4	8A60	16	Injection	Cranking fuel
FD74	FD78	FAE4		16		Idle RPM upper limit
FD84	FD88	FAF4		16		Idle RPM lower limit
FDED	FDF1	FB5D		2		Min Amal value
FDEF	FDF3	FB5F		2		Max Amal value
FDF1	FDF5	FB61		2		Boost reduce RPM value
FE07	FE0B	FB77		8		Amal ACT multiplier header
FE0F	FE13	FB7F		8		Amal ACT multiplier table
FE17	FE1B	FB87		16		Amal map MAP header
FE37	FE3B	FBA7		8		Amal map RPM header
FE47	FE4B	FBB7		128		Amal map table 16x8
FECF	FED3	FC3F		2		Excess boost cut out pressure
FED0	FED4	FC40		2		Excess boost reset pressure
FEDD	FEE1	FC4D		16	Ignition	Warm up ignition correction
		FC60		16	Injection	Warm up enrichment correction
		FCCB	8D00	64	Ignition	Knock limit table
		FDD8		64		Faulty MAP calculation values

The important point to note is that the addresses listed are the absolute locations in the memory map. If you read an EPROM on an EPROM programmer then the address will not have the same starting point. Hence a level 6 ecu which has its memory from E000 - FFFF will appear as 0000 - 1FFF on the programmer. So the rev limit at FD46 will be at 1D46.

Modifications

The P8 ecu is the only one which carries out a checksum test on the eprom at power up, so if you change any of the values then you will need to calculate a new checksum. This is obviously impractical when constantly changing values, so the easiest option is to disable the test so it always passes by changing the value at 94CFh from 27h to 20h. The checksum word is stored at 800Eh & 800Fh.

The stage 1 upgrade chip is usually just a standard chip with the rev limit raised and the over boost fuel cut disabled. Fuel and ignition maps are left as standard. Things become more complicated on Stage 2 and greater chips as a change of injectors for ones with greater flow rate and a 3 bar map sensor makes the map scales totally different.

Rev limit

To prevent the engine being damaged by over speeding the engine when accelerating, two rev limiters are implemented in software. The first is a soft cut at 6793rpm which cuts alternate fuel injection cycles and the second is a hard cut at 6996rpm which cuts all the fuel injection cycles. These values are usually changed to 7560rpm and 7780rpm respectively in a modified chip to allow for modifications which push the power band up the rev range.

L1=FD44

L6=FD48

L8=FAB4

P8=8CD8

The above values are the locations of the 16 bit word which defines the soft cut limit.

A typical value will be 0114 in hex which is 276 decimal.

L1=FD42

L6=FD46

L8=FAB2

P8=8CD6

The above values are the locations of the 16bit word which defines the hard cut limit.

A typical value will be 010C in hex which is 268 in decimal.

The engine speed is a value which is captured every 180 crank degrees from a 16 bit counter which is incremented at 1MHz and then divided by 16, so the faster the engine goes the smaller the number becomes. Hence 276 is 6793 rpm and 268 is 6996 rpm.

To calculate the value required use :- VALUE = 1875000 / RPM.

 

Boost limit

This is a safety device built in to the program to turn off the injectors if the boost goes too high and not re-enable it until it drops below another value. By raising the value to FF the value can never be exceeded so the boost can be turned up as high as required (as long as the fuel capacity of the injectors isn't exceeded causing a lean mixture).

L1=FECF

L6=FED3

L8=FC3F

The above values are the locations of the byte which defines the excess boost cut out pressure.

A typical value will be F0 in hex which is 240 in decimal.

L1=FED0

L6=FED4

L8=FC40

The above values are the locations of the byte which defines the excess boost reset pressure.

A typical value will be DC in hex which is 220 in decimal.

The 8 bit MAP sensor value is used as the input with 0 being max vacuum and 255 being max boost. (1 bar on a 2 bar map sensor).

The P8 uses a far more complex method than a single over boost trip limit, with the value depending on engine speed, ACT and an extra over boost allowance for a short time period.

 

Fuel Map

L1 = FA90

L6 = FA94

L8=F800

P8 = 8800

 

The 256 byte block of data below is the main fuel table for a level 6 ecu.

01	55	01	A1	01	D5	02	18	02	71	02	AA	02	EE	03	41
03	AA	04	12	04	94	05	3B	06	1B	07	53	09	28	0C	35
01	20	01	5A	01	93	02	24	02	AE	03	3E	03	DF	04	AF
05	73	06	42	07	12	08	04	09	01	09	01	09	01	09	01
CE	CE	D4	CB	D0	D0	D1	D1	D1	D1	D7	E7	F1	FB	F0	E6
B5	B5	B9	B1	B5	B5	B6	B6	B6	B6	BD	C8	D2	D6	D1	C6
9E	9E	A0	9D	9C	9C	9E	9F	9E	9D	A4	AA	B5	B3	B4	A7
8D	8D	8D	89	87	88	89	8C	8A	88	8E	91	9C	96	9A	92
7A	7A	7A	74	72	74	74	77	76	74	78	78	82	7D	80	7C
66	66	66	5E	5E	60	60	63	64	61	64	60	6B	67	67	67
4E	4E	50	46	47	4B	4A	4C	4E	4C	4E	4A	52	4E	4F	51
3B	3B	3C	35	36	3B	39	3A	3D	3D	3E	39	40	3C	3C	40
29	29	2B	27	28	2A	28	28	2B	2E	2D	29	31	2C	2C	30
1B	1A	1D	1B	1B	1E	1C	1C	1E	21	1E	1C	21	1D	1C	22
0D	0C	0D	0F	10	12	11	11	13	14	0F	0F	11	0D	0E	12
09	08	08	09	0A	0C	0A	0A	0D	0B	0C	0A	0A	07	07	0C
05	06	06	06	05	05	05	05	05	04	04	04	03	02	02	02

The top two rows are the RPM headers, the next two rows are the MAP headers and the following 13 rows are the actual fuel map itself. The headers use words and the map uses bytes.

RPM header

Converting hex to decimal and using the formula RPM = 1875000 / VALUE we get

0155	01A1	01D5	0218	0271	02AA	02EE	0341	03AA	0412	0494	053B	061B	0753	0928	0C35
5498	4496	3998	3498	3000	2749	2500	2250	1999	1799	1599	1350	1150	1000	800	600

Each of the 16 rpm sites applies to one of the 16 columns in the fuel map so we have a spread from 600rpm - 5498 rpm.

The P8 uses the formula RPM = 25600000 / VALUE.

MAP header

Converting hex to decimal and then to a pressure in bar we get

0120	015A	0193	0224	02AE	033E	03DF	04AF	0573	0642	0712	0804	0901	0901	0901	0901
288	346	403	548	686	830	991	1199	1395	1602	1810	2052	2305	2305	2305	2305
0.21	0.25	0.29	0.40	0.50	0.60	0.72	0.87	1.01	1.16	1.31	1.49	1.67	1.67	1.67	1.67

The last 4 values are the same so this forces the table to be only 13 long. Each of these 13 MAP values will correspond with each of the 13 rows in the fuel map. On a 2 bar map sensor 1380 is approximately atmospheric pressure with 0 being -1 bar and 2760 being +1bar. The 16 bit map value is created from the 8 bit map value from the A-D converter but is modified by altitude compensation at power up, the mixture adjustment pot and ACT. So we have a spread from 288 which is full vacuum on deceleration (0.20 bar) to 2305 which is max boost (1.67 bar). The values are biased closer together around the idling end of the scale where the mixture is most critical for emissions / smooth running and then more spaced out under boost.

A close approximation is 16bit MAP value = 1380 x manifold pressure (bar) assuming 40'C ACT temperature.

Hence the fuel map is a 16 x 13 table of bytes.

	600	800	1000	1150	1350	1599	1799	1999	2250	2500	2749	3000	3498	3998	4496	5498
1.67	CE	CE	D4	CB	D0	D0	D1	D1	D1	D1	D7	E7	F1	FB	F0	E6
1.49	B5	B5	B9	B1	B5	B5	B6	B6	B6	B6	BD	C8	D2	D6	D1	C6
1.31	9E	9E	A0	9D	9C	9C	9E	9F	9E	9D	A4	AA	B5	B3	B4	A7
1.16	8D	8D	8D	89	87	88	89	8C	8A	88	8E	91	9C	96	9A	92
1.01	7A	7A	7A	74	72	74	74	77	76	74	78	78	82	7D	80	7C
0.87	66	66	66	5E	5E	60	60	63	64	61	64	60	6B	67	67	67
0.72	4E	4E	50	46	47	4B	4A	4C	4E	4C	4E	4A	52	4E	4F	51
0.60	3B	3B	3C	35	36	3B	39	3A	3D	3D	3E	39	40	3C	3C	40
0.50	29	29	2B	27	28	2A	28	28	2B	2E	2D	29	31	2C	2C	30
0.40	1B	1A	1D	1B	1B	1E	1C	1C	1E	21	1E	1C	21	1D	1C	22
0.29	0D	0C	0D	0F	10	12	11	11	13	14	0F	0F	11	0D	0E	12
0.25	09	08	08	09	0A	0C	0A	0A	0D	0B	0C	0A	0A	07	07	0C
0.21	05	06	06	06	05	05	05	05	05	04	04	04	03	02	02	02

The values in the table increase with manifold pressure vertically and with maximum engine torque horizontally. The values are not actual injection times as there are a number of correction factors applied such as a table multiplier, battery volts, coolant temperature etc.

Note - If you swap the MAP sensor from a 2 bar type to a 3 bar type then the table headers will change to the values in the table below.

0120	015A	0193	0224	02AE	033E	03DF	04AF	0573	0642	0712	0804	0901	0901	0901	0901
288	346	403	548	686	830	991	1199	1395	1602	1810	2052	2305	2305	2305	2305
0.27	0.33	0.38	0.52	0.65	0.79	0.94	1.14	1.33	1.53	1.73	1.96	2.20	2.20	2.20	2.20

A close approximation is 16bit MAP value = 1050 x manifold pressure (bar) assuming 40'C ACT temperature.

The P8 uses 16 sites instead of 14 and a 2.5bar map sensor.

 

Ignition Map

L1 = FC80

L6 = FC84

L8=F9F0

P8 = 8AA0

 

The 176 byte block of data below is the ignition table for a level 6 ecu.

01	20	01	39	01	55	01	77	01	A1	01	D5	02	18	02	71
02	AA	02	EE	03	41	04	12	05	3B	07	53	09	28	0E	A6
00	E7	01	B0	02	24	03	3E	05	73	07	12	09	01	09	E8
30	27	26	20	18	10	0C	08	06	02	08	16	22	2C	32	36
30	2C	2E	2E	2C	1E	1A	17	14	10	20	30	38	3E	42	46
30	2D	32	38	36	34	33	32	33	37	3C	42	47	4B	4F	52
30	28	28	28	2B	2E	32	36	3C	42	47	4B	4F	52	55	58
38	28	28	1C	1B	1F	27	32	3B	48	52	57	5B	5E	60	62
40	40	40	2A	26	26	30	3C	44	53	5C	67	70	73	76	78
40	40	40	33	2F	2F	35	3C	43	50	5B	68	76	80	86	88
40	40	40	3D	3B	3C	3D	3F	42	49	56	67	7A	88	8C	8F

The top two rows are the RPM headers, the next row is the MAP header and the following 8 rows are the actual ignition map itself.

RPM header

Converting hex to decimal and using the formula RPM = 1875000 / VALUE we get

0120	0139	0155	0177	01A1	01D5	0218	0271	02AA	02EE	0341	0412	053B	0753	0928	0EA6
6510	5990	5499	5000	4496	3998	3498	3000	2749	2500	2251	1799	1400	1000	800	500

Each of the 16 rpm sites applies to one of the 16 columns in the fuel map so we have a spread from 500rpm - 6510 rpm.

The P8 uses the formula RPM = 25600000 / VALUE.

MAP header

Converting hex to decimal and then to a pressure in bar we get

00E7	01B0	0224	033E	0573	0712	0901	09E8
231	432	548	830	1395	1810	2305	2536
0.17	0.31	0.40	0.60	1.01	1.31	1.67	1.84

Hence the ignition map is a 16 x 8 table of bytes.

	500	800	1000	1400	1799	2251	2500	2749	3000	3498	3998	4496	5000	5499	5990	6510
1.84	30	27	26	20	18	10	0C	08	06	02	08	16	22	2C	32	36
1.67	30	2C	2E	2E	2C	1E	1A	17	14	10	20	30	38	3E	42	46
1.31	30	2D	32	38	36	34	33	32	33	37	3C	42	47	4B	4F	52
1.01	30	28	28	28	2B	2E	32	36	3C	42	47	4B	4F	52	55	58
0.60	38	28	28	1C	1B	1F	27	32	3B	48	52	57	5B	5E	60	62
0.40	40	40	40	2A	26	26	30	3C	44	53	5C	67	70	73	76	78
0.31	40	40	40	33	2F	2F	35	3C	43	50	5B	68	76	80	86	88
0.17	40	40	40	3D	3B	3C	3D	3F	42	49	56	67	7A	88	8C	8F

These ignition values can be easily converted into actual advance values by dividing by 4, giving a resolution of 0.25 degrees and a maximum possible advance of 63.75 degrees. The final advance applied to the engine is slightly modified by factors such as engine / air temperature, external retard select inputs etc.

	500	800	1000	1400	1799	2251	2500	2749	3000	3498	3998	4496	5000	5499	5990	6510
1.84	12.0	9.75	9.5	8.0	6.0	4.0	3.0	2.0	1.5	0.5	2.0	4.0	8.5	11	12.5	13.5
1.67	12.0	11.0	11.5	11.5	11.0	7.5	6.5	5.75	5.0	4.0	8.0	12.0	14.0	15.5	16.5	17.5
1.31	12.0	11.25	12.5	14.0	13.5	13.0	12.75	12.5	12.75	13.75	15.0	16.5	17.75	18.75	19.75	20.5
1.01	12.0	10.0	10.0	10.0	10.75	11.5	12.5	13.5	15.0	16.5	17.75	18.75	19.75	20.5	21.25	22.0
0.60	14.0	10.0	10.0	7.0	6.75	7.75	9.75	12.5	14.75	18.0	20.5	21.75	22.75	23.5	24.0	24.5
0.40	16.0	16.0	16.0	10.5	9.5	9.5	12.	15.0	17.0	20.75	23.0	25.75	28.0	28.75	29.5	30.0
0.31	16.0	16.0	16.0	12.75	11.75	11.75	13.25	15.0	16.75	20.0	22.75	26.0	29.5	32.0	33.5	34.0
0.17	16.0	16.0	16.0	15.25	14.75	15.0	15.25	15.75	16.5	18.25	21.5	25.75	30.5	34.0	35.0	35.75

The P8 uses 10 sites instead of 8 and a 2.5bar map sensor.

 

Cranking decay enrichment map

L1 = FBD0

L6 = FBD4

L8=F940

P8 = 8980

 

The 96 byte block of data below is the fuel enrichment map.

00	21	00	28	00	2F	00	35	00	41	00	51	00	71	00	A2
00	05	00	69	00	9B	00	E1	00	F0	00	F8	00	FA	00	FA
18	14	13	12	11	10	10	10	28	20	1A	18	14	12	10	10
30	28	20	1C	16	13	10	10	50	2C	24	20	19	14	10	10
50	2C	24	20	19	14	10	10	B0	50	30	26	20	15	10	10
D0	50	30	26	20	15	10	10	F0	F0	90	30	20	15	10	10

The top row is the engine coolant temperature header, the next row is the engine revolution count header and the following 4 rows are the enrichment data.

ECT header

Converting the hex from the ect a-d into temperature ('c)

0021	0028	002F	0035	0041	0051	0071	00A2
-38	-31	-18	-15	-5	5	20	65

Revolutions header

Converting hex to decimal and subtracting from 255 we get the number of engine revolutions for that column since the engine started turning.

0005	0069	009B	00E1	00F0	00F8	00FA	00FA
250	150	100	30	15	7	5	5

Hence the cranking decay enrichment map is an 8 x 8 table of bytes.

	5	5	7	15	30	100	150	250
65'C	18	14	13	12	11	10	10	10
20'C	28	20	1A	18	14	12	10	10
5'C	30	28	20	1C	16	13	10	10
-5'C	50	2C	24	20	19	14	10	10
-15'C	68	40	28	23	1C	14	10	10
-18'C	B0	50	30	26	20	15	10	10
-31'C	D0	50	30	26	20	15	10	10
-38'C	F0	F0	90	30	20	15	10	10

These values can be can be turned into a multiplier by converting to decimal and dividing by 16.

	5	5	7	15	30	100	150	250
65'C	1.5	1.25	1.19	1.12	1.06	1	1	1
20'C	2.5	2	1.6	1.5	1.25	1.12	1	1
5'C	3	2.5	2	1.75	1.38	1.18	1	1
-5'C	5	2.75	2.25	2	1.56	1.25	1	1
-15'C	6.5	4	2.5	2.2	1.75	1.25	1	1
-18'C	11	5	3	2.38	2	1.31	1	1
-31'C	13	5	3	2.38	2	1.31	1	1
-38'C	15	15	9	3	2	1.31	1	1

These values may need to be increased if the engine runs correctly using the warm up enrichment correction once going but tends to stumble / die a few seconds after starting from an overnight cold start, but is ok after a restart. Cylinder head material, inlet port design, injector positioning can all affect the amount of extra fuel an engine needs to compensate for the fuel dropping out of the airstream before it reaches the cylinder. This is only a short term compensation as 250 revs is only about 15 seconds at 1000 rpm. It starts decaying as soon as the engine starts cranking and keeps decaying as the engine , hopefully, starts running. The amount of fuel injected can be observed to reduce during extended cranking of a non starting engine.

 

ECT calibration table

L1 = FC70

L6 = FC74

L8=F9E0

P8 = 8A90

 

These 16 bytes of data convert the 8 bit value from the a-d converter for the ect input from a nonlinear value into a more evenly spread value for use by other look up tables.

F0

F0

F0

B2

98

89

7C

71

67

5C

52

47

3A

23

00

00

Transposing the ect voltage using the table creates

-55

-43

-31

-19

-7

5

17

29

41

53

65

77

89

101

113

125

Hence the value has gone from an exponential curve to a linear value which increases by 10hex per 12'C. Changing the ect sensor for one with a different output resistance v temp curve will require modification to this table to keep the same conversion values else all the ecu tables will have to be recalibrated.

 

ACT calibration table

L1 = FC60

L6 = FC64

L8=F9D0

P8 = 8A80

 

Like the ect table, these 16 bytes of data convert the 8 bit value from the a-d converter for the act input from a nonlinear value into a more evenly spread value.

F0

E2

E2

C5

B8

AF

A6

A2

9C

98

92

8C

84

76

5E

00

Transposing the act voltage using the table creates

-55

-55

-55

-55

-55

-55

-55

-35

-15

5

25

50

75

100

125

125

The act value is not used directly in any 16 byte look ups so it has been compressed over a 9 byte span.

 

Warm up enrichment table

L1 = FBB0

L6 = FBB4

L8=F920

P8 = 8950

 

L8=FC60

 

 

This 16 byte table is a multiplier for the fuel injection time relative to engine coolant temperature.

7A

7A

7A

75

6D

61

54

4D

49

45

42

40

40

3F

3F

3F

This table uses the ect table as a look up offset. To convert a table value to a multiplier value you convert it to decimal and use the formula:-

multiplier = value / 64

So it becomes:-

-55'C

-43'C

-31'C

-19'C

-7'C

5'C

17'C

29'C

41'C

53'C

65'C

77'C

89'C

101'C

113'C

125'C

x1.91

x1.91

x1.91

x1.83

x1.70

x1.52

x1.31

x1.20

x1.14

x1.08

x1.03

x1.00

x1.00

x0.98

x0.98

x0.98

As can be seen from the above, the amount of fuel injected is nearly doubled at arctic temperatures and actually leaned off slightly when the temperature reaches 100'C. A value of 40hex will create a multiplier value of exactly 1, so no change is made to the fuel quantity injected.

The L8 ecu also has the same table at FC60 (with a slightly richer set of values) which is used after the engine is started for about half a minute and then changes over to the above one (unless the engine temperature was lower than about 15'C in which case it will use the table until 65'C has been reached before switching).

 

Wide open throttle (WOT) enrichment table

L1 = FC30

L6 = FC34

L8=F9A0

 

 

This 16 byte table is a multiplier for the fuel injection time relative to engine speed, which is added if the throttle is determined to be open far enough to require it.

8D

8D

8D

8D

8D

8C

8C

8C

8C

8A

91

97

97

97

98

98

This table uses the fuel map rpm header as a look up offset. To convert a table value to a multiplier value you convert it to decimal and use the formula:-

multiplier = value / 128

So it becomes:-

600	800	1000	1150	1350	1599	1799	1999	2250	2500	2749	3000	3498	3998	4496	5498
x1.10	x1.10	x1.10	x1.10	x1.10	x1.09	x1.09	x1.09	x1.09	x1.08	x1.13	x1.18	x1.18	x1.18	x1.19	x1.19

As can be seen from the above, the amount of extra fuel injected is 10 percent at low rpm and 18 to 19 percent extra when exceeding 3000rpm, to keep a safe rich mixture when accelerating hard.

 

Cranking fuel table

L1 = FD64

L6 = FD68

L8=FAD4

P8 = 8A60

 

This 16 byte table is used to control the injection period for the first injection cycle when the the engine is cranking over.

F9

F9

F4

9C

45

27

1D

19

15

11

0D

0D

0D

0D

0D

0D

This table uses the ect table as a look up offset. To convert a value to an injection time you multiply the looked up number by 100h, convert to decimal and multiply by 4uS (which is the injector clock frequency). So it becomes:-

-55'C

-43'C

-31'C

-19'C

-7'C

5'C

17'C

29'C

41'C

53'C

65'C

77'C

89'C

101'C

113'C

125'C

255mS

255mS

250mS

160mS

71mS

40mS

29.7mS

25.6mS

21.5mS

17.4mS

13.3mS

13.3mS

13.3mS

13.3mS

13.3mS

13.3mS

This table is the equivalent of pumping the throttle pedal on an old carburetor fed engine to squirt extra fuel into the manifold. As can be seen from the above, at very cold temperatures the injectors will fire a large amount of fuel into the manifold to compensate for fuel condensing on the cold walls. Changing the injectors for ones with more flow will need a proportional reduction in these values to prevent the engine flooding before it can even start. Also some engines with more efficient designs of manifold / injector spray patterns can cope with a lot smaller values.

 

Amal Map

L1 = FE17

L6 = FE1B

L8 = FB87

 

The 176 byte block of data below is the amal table for a level 6 ecu.

00	85	00	95	00	B4	00	B9	00	BC	00	C3	00	C5	00	C8
00	C9	00	CC	00	D1	00	D2	00	D5	00	D6	00	DB	00	DC
01	14	01	20	01	39	01	46	01	77	01	D5	02	71	02	EE
00	04	82	8C	C8	FF	FF	FF	FF	FF	FF	FF	FF	FF	FF	FF
00	00	00	04	50	5A	C8	FF	FF	FF	FF	FF	FF	FF	FF	FF
00	00	00	00	04	14	8C	C8	FF	FF	FF	FF	FF	FF	FF	FF
00	00	00	00	04	14	8C	C8	FF	FF	FF	FF	FF	FF	FF	FF
00	00	00	00	00	00	04	14	8C	C8	FF	FF	FF	FF	FF	FF
00	00	00	00	00	00	00	00	04	32	53	C8	C8	C8	C8	C8
00	00	00	00	00	00	00	00	00	00	00	00	00	4C	4C	4C
00	00	00	00	00	00	00	00	00	00	00	00	00	04	04	04

The top two rows are the MAP headers, the next row is the RPM header and the following 8 rows are the actual amal map itself.

MAP header

This uses the 8 bit corrected MAP value so converting hex to decimal and then to a pressure in bar we get

0085	0095	00B4	00B9	00BC	00C3	00C5	00C8	00C9	00CC	00D1	00D2	00D5	00D6	00DB	00DC
133	149	180	185	188	195	197	200	201	204	209	210	213	214	219	220
1.18	1.32	1.59	1.63	1.66	1.72	1.73	1.76	1.77	1.79	1.84	1.85	1.87	1.88	1.92	1.93

Each of the 16 map sites applies to one of the 16 columns in the amal map so we have a spread from 1.18bar - 1.93bar.

RPM header

Converting hex to decimal and using the formula RPM = 1875000 / VALUE we get

0114	0120	0139	0146	0177	01D5	0271	02EE
6793	6510	5990	5752	5000	3998	3000	2500

Hence the amal map is a 16 x 8 table of bytes.

	1.93	1.92	1.88	1.87	1.85	1.84	1.79	1.77	1.76	1.73	1.72	1.66	1.63	1.59	1.32	1.18
2500	00	04	82	8C	C8	FF	FF	FF	FF	FF	FF	FF	FF	FF	FF	FF
3000	00	00	00	04	50	5A	C8	FF	FF	FF	FF	FF	FF	FF	FF	FF
3998	00	00	00	00	04	14	8C	C8	FF	FF	FF	FF	FF	FF	FF	FF
5000	00	00	00	00	04	14	8C	C8	FF	FF	FF	FF	FF	FF	FF	FF
5752	00	00	00	00	00	04	14	8C	C8	FF	FF	FF	FF	FF	FF	FF
5990	00	00	00	00	00	00	00	00	04	32	53	C8	C8	C8	C8	C8
6510	00	00	00	00	00	00	00	00	00	00	00	00	00	4C	4C	4C
6793	00	00	00	00	00	00	00	00	00	00	00	00	00	04	04	04

The amal table is used to create a pwm value to drive the valve with FF being fully open (maximum boost) and 00 being fully closed (minimum boost). As can be seen from the pattern of bytes above, the valve is fully open at low revs and low boost pressure (top right) and then progressively closed as the revs rise above 5752rpm or the boost exceeds 1.76 bar absolute. The value is further modified by air charge temperature (boost reduced if ACT too high or too low) and also if the revs are held above 6250rpm. The level 8 map has altered MAP headers and table values to allow a higher boost pressure in general and also more boost at higher rpm. A change to a 3 bar map sensor will require changes to the MAP header to allow for the modified range.

 

Amal ACT multiplier header / table

L1 = FE07

L6 = FE0B

L8 = FB77

 

The 16 bytes of data, shown below, are the same for all ecu types. The first 8 bytes are the header for the next 8 bytes which are the table.

8B

93

9E

A9

B0

B9

C0

C9

00

80

FF

FF

F5

E4

D2

C8

The header bytes define which ACT value relates to which column in the next table

8B	93	9E	A9	B0	B9	C0	C9
0'C	9'C	22'C	39'C	50'C	64'C	75'C	89'C

The table itself contains the multiplier values in the range of 0 to 1

00	80	FF	FF	F5	E4	D2	C8
x 0.0	x 0.5	x 1.0	x 1.0	x 0.96	x 0.89	x 0.82	x 0.78

Hence we get

0'C	9'C	22'C	39'C	50'C	64'C	75'C	89'C
x 0%	x 50%	x 100%	x 100%	x 96%	x 89%	x 82%	x 78%

The multiplier is used to modify the amal pwm value. Full boost is only available with an air charge temperature from 22'C to 39'C. Above 80'C the boost will be reduced by about 20% to reduce the risk of knocking and below 0'C the valve will be totally closed causing boost to reduce to its minimum. The lower end temperatures are set low to prevent engine damage when thrashing an engine from cold and would be unlikely to be encountered on a hot engine with a standard intercooler in the UK but may be encountered with a very big intercooler.

 

Injector start point phasing

L1 = FC50

L6 = FC54

L8=F9C0

P8 = 8A70

 

This 16 byte table below for the level 6 is used to control the point at which the injection period begins v engine rpm.

80

80

80

80

80

60

60

60

60

40

40

20

20

20

20

20

This table uses the rpm header from the fuel map as a header.

600	800	1000	1150	1350	1599	1799	1999	2250	2500	2749	3000	3498	3998	4496	5498
80	80	80	80	80	60	60	60	60	40	40	20	20	20	20	20
270'	270'	270'	270'	270'	180'	180'	180'	180'	90'	90'	0'	0'	0'	0'	0'

All angles are multiples of 90' and are taken from the cylinder being at TDC on its firing stroke (in preparation for the next cycle). At idling rpm the injection period will be short, so it is started 270 degrees late, so it occurs just before the inlet valve opens (90' before tdc on exhaust stroke). At high rpm the injection starts straight away to give maximum time for the injector before the inlet closes. Only values of 20h,40h,60h,80h are used (the larger the number the greater the delay). The L8 makes the change to 0' delay at a lower rpm then the L1 & L6.