Hi,


I was wondering if anyone can explain what the data byte means on the top column in fuel compensation,


My car was tuned at 57 Degrees(temp outside), and it seems to run good around 54-58 degrees, but runs like crap under 45 degrees out side, Feels too rich.


Anyone ways if anyone knows this would help me a lot in understanding how to fix it.

not sure if it matters but:
3.6 liter rev up.
11:1 comp
s7 cams
port, polish, mrev2 spacer, all bolt ons. balanced block, forged pistons/ rods.

Also attached my fuel and timing tables for refference

 

over 6000 rpms they have it tuned very rich - most cars like it around 13:0. I'm assuming they did this because they are staying on the safe side for detonation as you are revving up beyond the normal redline.

Temp compensation is for air density. Cold air = more dense which means more oxygen. Hot air = less dense.

more air = more fuel for to achieve same A/F ratio (also means more power)

If you feel like you are too rich below certain temps you can try pulling back a little fuel for lower temps.

Proper tuning makes it hard to dial in for different temperatures. Its a "best guess" scenario even if you are using mathematical equations for dialing in temperature adjustments.

*EDIT* that map is not for Air Temp compensation*

That top column normally represents ENGINE LOAD

 

Yeah, Good call on that.

I was detonating a bit so so we had to make it a bit more rich to run with that amount of timing, its what my set up liked best.

So if I am correct you are saying the car automatically compensate for the density based on temperature automatically? and I cant adjust it?

Also If in the compensation table if that is load can you explain to me how that may work? I was a bit confused.

Basically when I was reading uprev manuel it says that you set your targets, but if you dont adjust your compensation right it will never hit the targets, it will be bouncing around.

I guess my real question that it comes down to is that, if that is rpm vs base load( or air denisty), and that is how much percent of fuel it should give based on that load, shouldnt there also be a point where it is over 100%?




It says to set everythig to like 11.7 except for the top row and rev it and tune until it hits it all constantly, but I don't have a external wideband AF to check that, plus the stock wides arent that acurate.

so I am just trying to understand how it works so I can adjust it.

 

the G35 ECU will automatically adjust - but you should be able to modify what its doing as well. I know that the UTEC has this as an option as well as a lot of other piggy-back setups.

the 100% is the MAX fuel it will go given at full engine load. you tune to MAX load and then adjust downward for less load. It shouldn't go over 100%.

In order to test your A/F settings and adjust you really should get a Wideband. Stock O2 sensors aren't as good and are calibrated for the ECU not tuning purposes that you would be doing.

 

hmm, yea I do think I should get a wideband, and get it installed in my car, good it monitor whats going on.


Also can anyone else chime in on where we can adjust it?

and Also If Im tuning for max load on the far right column, should each colum be a similar less, like one column to the left like 1 percent down,then the next one over 1.5 percent down etc?