14CUX downloaded fuel maps from EPROMS

[Dalamar]

Hello. Some background first...

My car (1995 4.0L Chimaera with cats) came with a 'Mark Adams' style fueling chip, the one with the decoder board, but with no other identifying stickers attached. Could be a Tornado chip or someone's rolling road fuel maps. Anyway, I was surprised that I could download the fuel maps from the EPROM chip using Rovergauge and upload it into TunerPro after a quick tweak with the 14CUX Toolkit to copy/double the downloaded information.

The fuel map that I currently use is from Steve Sprint's website which is great, less shunting, lower idle RPM and the revs drop quicker when rolling to a stop. This map is based on the R3652 program code as compared to my original chip which was based on the R3116.

Using TunerPro I've compared the two Map 5 fuel maps and seen that my original chip generally provides a leaner map compared to Steve's. In simple terms, the values in each cell had a lower value in my original fuel map as compared to Steve's. I did suspect this as I noticed the fuel consumption is a touch higher than my original chip. Nevertheless, I can still achieve >30mpg driving like a granddad along the motorway.

Just for fun - what I'd like to do is to copy the fuel map from my original chip onto Steve's Map 5 (cat map) to see how the car would perform. Question is - do I need to copy across any of the other smaller tables to go with this main fuel map?

Also, can someone please point me to a reference document or website that explains all the different tables and scalars? Some examples are:
MAP 5 THROTTLE TABLE (not sure)
MAP 5 START UP ENRICHMENT (as the name suggests)
MAP 5 TEMPERATURE FUEL MULTIPLIER (as the name suggests but I'm not sure if this is important for a specific map)

Finally can we ignore the OLD FUEL TABLEs? I presume these are for the older 13/14CU units?

[blitzracing]

I cant give you that level of detail, but all I did was copy the white tune raw map data into the green tune to start with, then altered it to give me the AFRs I wanted under different engine loads with the load cells. I did not alter anything outside of the map. I did check the live map shown in RoverGauge matched the one in tuner pro I was altering to make sure there was no confusion.

[stevesprint]

Dalamar
Great to hear from you and thanks for your kind words regarding my R3652, I've learnt a lot since then and now run R3365.

Sounds like you know what you’re doing and making amazing progress considering the lack of documentation which I’m to blame for, sorry. However I’m always online & ready to help but you may need to send me an email to grab my attention.

Dalamar said:

Using TunerPro I've compared the two Map 5 fuel maps and seen that my original chip generally provides a leaner map compared to Steve's. In simple terms, the values in each cell had a lower value in my original fuel map as compared to Steve's. I did suspect this as I noticed the fuel consumption is a touch higher than my original chip. Nevertheless, I can still achieve >30mpg driving like a granddad along the motorway.

Although at first glance your original R3116 map may appear leaner it may not be, you also need to take into account the airflow meter row scalar, the main multiplier, engine temperature fuel multiplier and Full Load Fuel Additive.

For example a higher row scalar will move the active row down the main fuel table so richer cells come into play, also a higher temperature multiplier at 90°C in the temperature adjustment table will also make the whole of the main fuel table run richer at 90°.

Dalamar said:

Just for fun - what I'd like to do is to copy the fuel map from my original chip onto Steve's Map 5 (cat map) to see how the car would perform. Question is - do I need to copy across any of the other smaller tables to go with this main fuel map?

Also, can someone please point me to a reference document or website that explains all the different tables and scalars? Some examples are:
MAP 5 THROTTLE TABLE (not sure)
MAP 5 START UP ENRICHMENT (as the name suggests)
MAP 5 TEMPERATURE FUEL MULTIPLIER (as the name suggests but I'm not sure if this is important for a specific map)

If the scalars are different and you want the same results then yes you should copy all of map5’s table and data and if it wasn’t a Mark Adams chip I would have offered to do it for you, sorry. In contrast cat map5s are usual leaner than precat map2 and therefore tend to have different scalars.

Here’s all the tables and data in each map (1 to 5) which you could copy complete with a Hex Editor like HxD from map 5 to map 5, but be very careful when copying from map5 to map2 or vice versa not to copy the sensor input order, you can then correct the checksum fixer with the toolkit as you know.

======== START OF MAP 5============================================
; TVR Chimaera 400 (1997)
LC6AF       DB  $21,$21,$21,$22,$21,$20,$1F,$1F,$1E,$1E,$1D,$1C,$1A,$19,$19,$19
            DB  $41,$41,$40,$3F,$3E,$3E,$3D,$3C,$3B,$3C,$3E,$3D,$37,$34,$34,$34
            DB  $60,$5E,$5D,$5D,$5B,$5A,$5A,$5A,$5A,$5B,$5B,$5C,$57,$4E,$4E,$4E
            DB  $88,$84,$82,$82,$83,$83,$80,$7C,$7D,$7D,$80,$85,$78,$6C,$6C,$6C
            DB  $B4,$AF,$A5,$A5,$A0,$A0,$A0,$A0,$A1,$A3,$A4,$A7,$96,$8C,$8C,$8C
            DB  $FF,$FF,$D2,$D2,$D2,$CD,$CD,$CD,$CB,$CB,$CE,$CE,$B2,$B2,$B4,$C3
            DB  $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$F5,$EF,$EB,$E1,$DC,$DE,$DE
            DB  $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF,$FA,$FA,$FF,$FF,$FD,$FD

LC72F       DW      $56CC               ; fuel map multiplier


MAP 5 THROTTLE TABLE
; This 6 x 10 table is used to calc the throttle pot direction & rate 
; the resultant value is used to dynamically adjust the fueling briefly
; If temperature is $23 the 2nd col would come into play.
LC731       DB      $18,$31,$5A,$73,$89,$99,$B3,$CC,$DD,$EA    ; <-- coolant temp (low is hot, high is cold)
LC73B       DB      $05,$06,$08,$0A,$10,$1C,$23,$28,$30,$30    ; <-- throttle opening (compare value or limit)
LC745       DB      $04,$06,$07,$08,$08,$00,$00,$00,$00,$00    ; <-- throttle closing (compare value or limit)
LC74F       DB      $2D,$32,$3C,$50,$64,$FF,$FF,$FF,$FF,$FF    ; <-- throttle opening (multiplier)
LC759       DB      $1C,$18,$10,$0C,$0B,$14,$14,$19,$19,$19    ; <-- throttle opening (multiplier)
LC763       DB      $24,$18,$10,$0C,$0B,$1E,$1E,$1E,$1E,$1E    ; <-- throttle closing (multiplier)

MAP 5 START UP ENRICHMENT (as the name suggests)
; Cranking fuel based on engine temperature
LC76D    DB   $00,$12,$1B,$25,$47,$75,$99,$B0,$C8,$DA,$E4,$E8 ; <-- coolant temp (low is hot, high is cold)
LC779    DB   $0B,$0A,$07,$0D,$1A,$1C,$31,$46,$4E,$59,$6D,$75 ; <-- cranking fueling value
LC785    DB   $1C,$0D,$06,$0A,$10,$12,$1E,$26,$2C,$31,$39,$44 ; <-- time decay 1 Hz countdown

MAP 5 TEMPERATURE FUEL MULTIPLIER
; Fuel adjusment table based on temperature (warm up extra fuel)
LC791       DB      $00,$24,$38,$91,$AB,$C2,$E0,$EE ; (C791)
LC799       DB      $26,$26,$29,$2C,$32,$38,$43,$4E ; Fuel adjust
LC7A1       DB      $00,$09,$02,$0E,$10,$17,$32,$14 ; slope between columns


; this is the round robin sensor input control list, (FA terminates list)
LC7A9       DB  $87,$86,$02,$03,$84,$02,$8D,$88,$02,$8B,$80,$85,$81,$8E,$FA,$FA ; Sensor input mux list


LC7B9       DB  $B9       ; AFM Row Scalar, used to calc the fuel table row based on load
LC7BA       DB  $1B       ; RPM limiter Safety margin 
LC7BB       DW  $04B0     ; RPM limiter (7500000/1200dec = 6250 RPM)
LC7BD       DB  $6E       ; Fuel cut overrun temp threshold
LC7BE       DB  $2C       ; unknown Warm up threshold
LC7BF       DB  $5C       ; Full load Fuel Additive
LC7C0       DB  $64       ; Deceleration Gain

======= END OF MAP5 =============================

This next table is NOT in the code but can be used to convert the above Hex 
temperatures to degrees C.
$24 is 2 down and 4 across therefore 86°C
;     0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F
; 0  130,129,127,126,124,123,121,120,118,117,115,114,112,111,109,108,  0
; 1  106,105,104,103,102,101,100, 99, 98, 97, 96, 95, 94, 93, 92, 91,  1
; 2   90, 89, 88, 87, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75,  2
; 3   74, 73, 72, 71, 70, 70, 69, 68, 67, 66, 65, 64, 63, 63, 62, 61,  3
; 4   60, 59, 59, 58, 58, 57, 56, 56, 55, 55, 54, 54, 53, 52, 52, 51,  4
; 5   51, 50, 50, 49, 49, 48, 48, 47, 47, 46, 46, 45, 45, 44, 44, 43,  5
; 6   43, 42, 42, 41, 41, 40, 40, 39, 39, 38, 38, 37, 37, 36, 36, 35,  6
; 7   35, 35, 34, 34, 33, 33, 32, 32, 31, 31, 30, 30, 29, 29, 28, 28,  7
; 8   28, 28, 27, 27, 26, 26, 26, 25, 25, 24, 24, 23, 23, 23, 22, 22,  8
; 9   22, 21, 21, 20, 20, 19, 19, 18, 18, 17, 17, 16, 16, 15, 15, 14,  9
; A   14, 14, 13, 13, 12, 12, 11, 11, 10, 10,  9,  9,  8,  8,  7,  7,  A
; B    7,  7,  6,  6,  6,  5,  5,  5,  4,  4,  3,  3,  3,  2,  2,  2,  B
; C    2,  1,  1,  0,  0, -1, -1, -2, -2, -3, -3, -4, -4, -5, -5, -6,  C
; D   -6, -6, -7, -7, -8, -8, -8, -9, -9,-10,-10,-11,-11,-11,-12,-12,  D
; E  -12,-13,-13,-14,-14,-15,-15,-16,-16,-17,-17,-18,-18,-19,-19,-20,  E
; F  -20,-20,-21,-21,-22,-22,-22,-23,-23,-23,-24,-24,-24,-25,-25,-25   F
;     0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F

Dalamar said:

Finally can we ignore the OLD FUEL TABLEs? I presume these are for the older 13/14CU units?

You can ignore the old maps as they are for 1992 and earlier 14CUXs like Precat 400s, but maybe useful if you want to see or copy a Precat 400 fuel table.

Please let me know if you want anything explained in more detail and I'll try my best with my limited knowledge.

Edited by stevesprint on Sunday 13th October 22:30

[Dalamar]

Thanks Mark and Steve for the info. One of the things I like about the R3652 tune is that the revs drop quickly when coasting to a stop. Could you please let me know the key parameters in the XDF file that alter this characteristic? I was thinking IDLE SPEED (All Tunes) and Coasting Idle Hold Up but am note sure if there are any other parameters to consider.

[stevesprint]

Dalamar

You’ve got the correct parameters.

The stationary target idle speed (closed loop idle) is IDLESPEED + NEURAL GEAR IDLE ADJ in decimal,
and increases by AC COMPRESSOR IDLE ADJ + SCREEN HEATED IDLE ADJUSTMENT when switched on.


Increasing “Coasting Idle Hold Up” lowers the coasting idle speed before stopping (open loop idle) however I have to admit I’ve just realised its address in TunerPro was point to the wrong copy in the chip and therefore wouldn’t work. The prom address/position should be hex 4242 not 242. Also please note its value is capped at 7F.

Here’s a fixed TunerPro definition file & I’m very sorry for any inconvenience caused.
www.remap-14cux.uk/software/TunerPro14CUXConfig.zi... .
You also need to copy the 14CUX_CHECKSUM2.0.dll into TunerPro's "Program Files" directory, for example "c:\Program Files\TunerPro" but yours maybe different.

High coasting idle speed is a common cause for complaint because TVR only raised the closed loop idle speed and didn’t adjust the open loop idle speed to suit.

Edited by stevesprint on Tuesday 15th October 22:43

[Dalamar]

Thanks Steve for the new XDF file. I'm running out of time now to test drive ROMs before I SORN the car in Nov but I will have a play over the winter. I sorted myself out with a old TL866A programmer and have ordered an AT28C256-15PU EEPROM too. Another thing I'll do is annotate the XDF file with the info you've supplied in the Description fields and will email you a copy to review. I've found the Description fields that are populated helpful to know what the parameter does and which way to adjust it (or leave well alone). Hopefully I'll be on the right track with what I want to use TunerPro for.

[SILICONEKID 357HP]

What are you lot talking about ?😂

Some people are very clever .

[SILICONEKID 357HP]

Is that the matrix? 😂

[Dalamar]

Update on this one.

I managed to merge my original rolling road fuel table and key characteristics with the latest R3652 file. The hardest thing was adjusting the RPM 'titles' in the fuel map but the online instructions were fine just took a bit of interpretation.

I've been running the merged tune file now for >1 year and it's been great. I also updated the XDF file with the parameters listed in this discussion and comments for future tweaks so that I can remember what does what.

The next challenge will be to play around with a wideband lambda.