Tuner Cat: Idle % Fuel/Air Table Question

I was wondering why this table has different numbers for air/ fuel for each cylinders that are the exact same size on a stock .bin???

Example: (Stock)

Cyl 1: 1.03
Cyl 2: 1.00
Cyl 3: 0.97
Cyl 4: 1.00
Cyl 5: 1.00
Cyl 6: 0.97
Cyl 7: 0.93
Cyl 8: 1.00

Now I understand 1.00 = 100%, but that table title says "% air/fuel" so which one does the % number represent, air or fuel?

Anyone who can clear this confusion up would be greatly appreciated. I mean in my mind I would think 1.00 would be best for all cylinders for idle... but why aren't they???? THX.

if you notice the cylinders closest to the throttle body are the ones that get more air/fuel

those no's represent fuel because that is the only thing that the car can modify. It cannot modify what each cylinder will get for air. I personally have a certain philosophy on this subject and it comes down to the fact that we cannot determine correct fueling mods without knowing what the AFR is coming out of each clylinder. Now think how practical that is.


Ben

Originally posted by 95Blackhawk
those no's represent fuel because that is the only thing that the car can modify. It cannot modify what each cylinder will get for air. I personally have a certain philosophy on this subject and it comes down to the fact that we cannot determine correct fueling mods without knowing what the AFR is coming out of each clylinder. Now think how practical that is.


Ben


Its called exhaust Gas Temperatures. Its used on almost all bench dynometers to get individual readings for each cylinder. You can set up the same system on a street car like the race cars do. Altho it does not measure A/F ratios its very accurate. example 1450 degrees F is too lean, 1300 F is too rich........Therefore you now have individual cylinder tuning:eek:

Originally posted by TriPinTaZ
Its called exhaust Gas Temperatures. Its used on almost all bench dynometers to get individual readings for each cylinder. You can set up the same system on a street car like the race cars do. Altho it does not measure A/F ratios its very accurate. example 1450 degrees F is too lean, 1300 F is too rich........Therefore you now have individual cylinder tuning:eek:

Confirm what I have read: at stoich. AFR, you will have the highest EGT's. If you go rich, they will drop and if they go lean, they will drop.

But again, I will ask, how practical is your suggestion. Is there a way easier than pulling the engine?

Ok here it goes.....

A leaner AF mixture will burn hotter than a Richer AFR. Therefor the following example applies

RICH AFR = ~1200F
Stoich AFR= ~1300 F
LEAn AFR= ~ 1400 F

This way you can individually tune each cylinder. And yes there is a better way than yanking the engine but it requires applying an EGT setup to your car. You will ahve to drill holes in your HEaders and to install them. They make these setups for race cars and Im sure you can get one on your car if you want to pay the $$$ for it.

One of our guys on WS6ZXR.com (trans-am forum) is using them on his car. It can be done :)

I agree with Blackhawk. AFAIC, using exhaust temps by themselves, is a crap shoot. They need to be re-enforced with A/F (accurate) ratio readings. Used alone, it is sorta like using oem O2 sensors as gospel. They could be accurate, but certainly do not have to be.

ref: http://www.sdsefi.com/techegt.htm