Air Fuel Ratio

[batesyellow01]

Ok,
I am new to EFI and have been doing slight changes this past month. You guys helped me out on correcting the timing table for NO2 at WOT. Just installed my wideband two days ago.It shows around 14.9 AFR at idle,then at a slow rev it jumps around quite a bit maxing guage out and then dropping back in the 12's then up again. I have checked for any leaks and cannot find any thinking that could be the problem. I have hollowed out cats
and the bung is welded in the 1 1/2" space right before the cat. I am thinking of swapping the WBO2 aroud with the LBO2 as they are only six inches apart.
My next question, with using NO2 wet shot I would still like to richen it up a bit. Which table do I concentrate on changing? If I am in the 14's and upward
thats sounds like possible detonation.At WOT with the NO2 I'd like to be in the 11-12 range correct?Oh, I just recently installed LT's , CAI, Descreened MAF , 160 thermo, gutted cats, x-pipe, Borla Stingers, so I'm sure with all the new free air I may be runnning lean. I have 57 to 62 LBS fuel pressure
pretty consistantly, also did an injector test all ranging between 795 and 815.
I did knock out 4 degree's of timing in the upper range to WOT for the No2 100 shot. So, any help on table to get my AFR lower would be highly appriciated.

[Beer99C5]

Hi Bates, wish mine idled at 14.9, mine is in the upper 15's :bawl:

I don't think there is anything wrong with your WB set up.

For the wet shot, to richen it up just increase the fuel jet size till you get it where you want it. You can fine tune the PE under Engine Calibration/Fuel/Mixture (Table 3618 )

[Redline Motorsports]

I would start with getting the basics dialed in first. Go to the tutorial section and get setup to do a session of AutoVE tuning. The VE table is the foundation for all fueling control and if its off, all the supporting trim tables will be less effective and out of skew.

You really need to get the motor dialed in PRIOR to spraying it. You should end up the a WOT AFR between 12.8-13.1 +/-. If you are using a wet kit, all fueling will controled via jetting of the NOS kit not from the tune calibration. Spray the car with a WB installed and see what AFR you have. Go from there. I typically set NOS cars between 11.7 to as lean as 12.1 depending on many other variables. 10 is too rich and is typical of many off the shelf kits.

Your ignition timing is going to be your critical tuning parameter. Because NOS fills the cylinders so quickly (or volumetrically efficiently!) less timing is needed. 4 degree with a 100 shot should be fine. I'd log a pull and confirm.

Howard