What you need to log and why

[norbs]

There seems to be a lot of people logging items that should be logged and they are not. The XFI can log 24 sensors max, if you go higher than 24 the next sensors will not display properly. It does not slow anything down if you log 1 or 24 sensors, like in the classic after 14 sensors the logging rate goes to a crawl. I also see people not logging VE% you must do this , since when you edit the map you wont be able to go back and see what the ve the ecu was using at the present time. Here is a generic list for XFI users, traction control , PA modes, boost control not included. Also always log at 20 fps.

Map (kpa)
rpm
psia
VE%
target a/f
actual a/f
o2 correction
spark btdc
cam sync btdc
error code
error code 2
coolant temp
batt volts
inj duty%
tps
esc rtd
aft.cor
cts.cor
air temp
mph
inj pw
target IAC
learning


I will be adding to this thread later when I have more time.

 

[trixdout]

So would VE% help a user/tuner to figure out what exhaust works best with the intake and engine (porting of the exhaust and intake ports)? Or is there more to it than that? Also what is a good target for VE%, since turbocharging is putting more air than the engine was ever supposed to take. So it should definitely be over 100%, but by how much? Im going to assume that it will vary from engine to engine.

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[turbobitt]

Forced induction doesn't mean over 100%. For example, if you have 15 psi boost and the cylinder is only getting filled with 12 psi than your less than 100%. Think of VE as the amount of cylinder fill with respect to the amount of available manifold pressure. I'm sure there is a better way to explain it then that.


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[pacecarta]

VE% is not a measured number , and only really applies to FAST XFI or other speed density based aftermarket ECU
ve ( volumetric efficiency ) is the fuel table values entered into the base fuel table by the tuner (or by the auto learn on 2.0) and when logging it it gives you the value applied when you are between cell centers

the VE number is what commands the initial injector opening and if you are closed loop enabled the ECU uses the VE first as to what to pusle the injector and then if af target isnt met it applies an O2 % correction
when you log you can review the data and correct the table accordingly , if you're lean (the VE number needs to go up , rich you need to enter a VE number lower to get the base fuel table closer to the engines true needs
heres my track list
Map (kpa)
rpm
o2 correction
actual a/f
target a/f
inj duty%
MAP (psia)
spark btdc
tps
coolant temp
air temp
batt volts
Fuel PSI
Alky PSI
oil PSI
esc rtd

if running double pumper on XFI control you could log the aux output so you can see its activated although if parameters its set it should activate

i dont see where actual ve% matters to the log as you will still need to adjust the table based on the bubble position and the correction applied for WOT use i would rather have fuel psi alky psi (if you run alky) and oil psi for WOT
at track and even if you are out on the road tuning hopefully you are warmed up before dropping the pedal so aft start % isnt needed and if you arent overheating (you logged Coolant temp) cts correction% isnt needed ,
iac target ....really !! that can be tuned at idle live during start and warmup and should be changed as needed and watch results live , no need to be logged at WOT
if you are tuning where aft or cts corr are apply you could add them using another dash and leave the 'dash for logging ' alone
mph ..why !!! it really doesnt have anything to do with your tuning

 

[norbs]

VE% is not a measured number , and only really applies to FAST XFI or other speed density based aftermarket ECU
ve ( volumetric efficiency ) is the fuel table values entered into the base fuel table by the tuner (or by the auto learn on 2.0) and when logging it it gives you the value applied when you are between cell centers

the VE number is what commands the initial injector opening and if you are closed loop enabled the ECU uses the VE first as to what to pusle the injector and then if af target isnt met it applies an O2 % correction
when you log you can review the data and correct the table accordingly , if you're lean (the VE number needs to go up , rich you need to enter a VE number lower to get the base fuel table closer to the engines true needs
heres my track list
Map (kpa)
rpm
o2 correction
actual a/f
target a/f
inj duty%
MAP (psia)
spark btdc
tps
coolant temp
air temp
batt volts
Fuel PSI
Alky PSI
oil PSI
esc rtd

if running double pumper on XFI control you could log the aux output so you can see its activated although if parameters its set it should activate

i dont see where actual ve% matters to the log as you will still need to adjust the table based on the bubble position and the correction applied for WOT use i would rather have fuel psi alky psi (if you run alky) and oil psi for WOT
at track and even if you are out on the road tuning hopefully you are warmed up before dropping the pedal so aft start % isnt needed and if you arent overheating (you logged Coolant temp) cts correction% isnt needed ,
iac target ....really !! that can be tuned at idle live during start and warmup and should be changed as needed and watch results live , no need to be logged at WOT
if you are tuning where aft or cts corr are apply you could add them using another dash and leave the 'dash for logging ' alone
mph ..why !!! it really doesnt have anything to do with your tuning

My suggestions cover overall tuning not just WOT so you can have it in all one dash. Knowing the actually ve , since its an iterpolated number just gives you an idea of what the ecu is doing. If your editing a map it makes it easier to have this number thats all. You confusing things a bit on ve. Its a calculated number of AIR not fuel techinally, it tells the ecu how much air , and the open loop air fuel target ratio determines the amount of fuel, based on the amount of air(ve).Its kind of confusing, but this is why its very important to have the open loop a/f ratio set properly...

 

[turbobitt]

I like to log VE simply because if it's in between cells, you can adjust one or both cells accordingly. Without knowing what the XFI is using for the calculation makes this difficult. Target A/F has almost no significant use since you can retrieve that later from the A/F table.


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[pacecarta]

like target VE target AF is also an interpolated value , important during spoolup and off the brake to target boost when af in table varies quickly
there are times when you can see the correction was positive (still in decay) from previous cell correction and yet actual vs target shows AF is richer than target .

 

[norbs]

Everyone has a slightly different approach to tuning, and that is fine, but this post was really intended for new XFI users, to learn the more about the system.

 

[turbobitt]

Just for reference, I found it in my best interest to use this logging list.

MAP
RPM
TPS
O2 Corr
VE %
Actual A/F
inj. DC
Battery V
DS RPM
Delta DS RPM
Exh Bk KPA (Exhaust Back pressure)
Fuel (PSI)
Wastegate (PSI)
Clutch Flag
MAP (PSIA)
EGT 1
EGT 2
EGT 3
EGT 4
EGT 5
EGT 6
X acceleration
Boost DC %
Air Temp