OBC fuel consumption change?

[nextelbuddy]

I have a factory tuned dme with larger 65lb injectors, now the obc is reporting higher mpgs as expected.

Is it possible to change a correction factor somewhere to get the obc mpg to be more accurate?

Would this be in the dme or the cluster?

[terra]

I *think* you can edit K_KVA_NORM (It's a multiplier with formula x/128, higher would mean more fuel consumption I believe). Stock value is 1.03125, maxes out at 1.99. Assuming the stock injectors are 24 lb, that would imply the largest injector your could correct the readings for would be ~46 lb (without doing a program modification that is).

[nextelbuddy]

thanks Terra for the information even if it doesn't allow adjustment for anything past 46lbs injectors, its still better and closer than what im getting now.

[terra]

Untested, but theoretically if you change 0xA8830 from 12 39 00 08 8B E8 to 32 39 00 08 8B E7, and then change 0xBE7 (0x88BE7) from 00 84 to 01 65, that should do the trick for 65 lb injectors (again, this is assuming the stock S54 injectors are 24 lbs).

Assuming we're talking about the CSL

[nextelbuddy]

Untested, but theoretically if you change 0xA8830 from 12 39 00 08 8B E8 to 32 39 00 08 8B E7, and then change 0xBE7 (0x88BE7) from 00 84 to 01 65, that should do the trick for 65 lb injectors (again, this is assuming the stock S54 injectors are 24 lbs).

Assuming we're talking about the CSL

i'm not using the CSL tune software, my turbo tune is on a stock MSS54HP DME based on the 211323002701-J469 tune file

[terra]

Try this
0xA80F6: 12 39 00 08 8C 12 to 32 39 00 08 8C 11
0xC11 / 0x88C11: 00 84 to 01 65

[nextelbuddy]

Try this
0xA80F6: 12 39 00 08 8C 12 to 32 39 00 08 8C 11
0xC11 / 0x88C11: 00 84 to 01 65

Wonderful thanks a lot, ill take a look at it soon.

[thegenius46m]

Bumping this. I just upgraded to 52lb injectors and have the same problem. It looks like the KVBR correction does not work on C23 and newer clusters so terra if you would be able to assist with the correct hex conversion for 52cc injectors on a csl dme that would be awesome.

[terra]

Still completely untested on my end. You can try:

0xA8830 from 12 39 00 08 8B E8 to 32 39 00 08 8B E7 (this is a program mod)
0xBE7 from 00 84 to 01 1E

[thegenius46m]

Still completely untested on my end. You can try:

0xA8830 from 12 39 00 08 8B E8 to 32 39 00 08 8B E7 (this is a program mod)
0xBE7 from 00 84 to 01 1E

Thanks so much! So first one is full bin and second one is partial bin. I found both but I just realized something and can’t remember why…

Partial bin, the one everyone messes with for tuning, etc… isn’t it technically just a snapshot over a specific range of the full bin? I tried to see if I could change the 0xBE7 values in the full bin but realized when comparing to the partial bin, the values in each file are indeed different. Is this a checksum thing or something else?


Sent from my iPhone using Tapatalk

[terra]

the partial is contained within the full binary, yes. 0xBE7 would be mapped to 0x88BE7. MSSFlasher doesn't correct the parameter checksums when flashing with a full binary though.

[thegenius46m]

the partial is contained within the full binary, yes. 0xBE7 would be mapped to 0x88BE7. MSSFlasher doesn't correct the parameter checksums when flashing with a full binary though.

Ahh makes sense. Thank you!


Sent from my iPhone using Tapatalk

[terra]

Any updates? Did the modification work?

[thegenius46m]

Any updates? Did the modification work?

I’ll give it a try tonight and report back. Got sidetracked with some stuff and didn’t have the chance.


Sent from my iPhone using Tapatalk

[thegenius46m]

Any updates? Did the modification work?

Didn't work. Looks like it bricked my dme entirely 🙃