Air Fuel
 

I am going to be buying a wideband air fuel gauge soon. I was wondering if anyone knew what reading i should get on a factory car? What it would be at idle? or what i would want to stay away from? The main reason i need to find out is because i am going to be spraying it more and if its running lean now that wouldnt be a good idea to spray it so i need to add more fuel or take away fuel one of the two depending on what it should be. If anyone could help out with the air fuel numbers i would greatly appreciate it. Thanks

Some of the mods on the car are: (motor only)
Hooker Longtubes, Hooker X-pipe w/o cats(rear o2's shutoff), flowmaster mufflers, diablosport predator programmer, 78mm BBK tb/intake combo, bbk cold air intake k&n air filter, 100 shot wet kit (but going to be spraying 125 come summer).

At idle you should see 14.7. At part throttle and cruise it should read between 14.6 and 15.7. The leaner at part throttle the better gas mileage. At WOT it should read 12.4 stock. 12.5 to 13.2 for best power NA. 10.5 to 11.2 for best safe power for FI. Around 11 for nitrous.

Not sure for FI cars but N/A it should be 12.8-13.1 is perfect for N/A car.

I thought 11.5 was the number to go for FI. Would that be unsafe?

Thanks alot for the replies it really helps alot since i have never had an air/fuel meter.

11.5 is fine

i actually that it was supposed to be 11.8 with FI

You will find that with the stock tune AFR will drop to 11.0:1 to 11.5:1 at WOT, which is too rich for optimal HP. I believe this was done deliberately to make damned sure there will be not detonation on 87 octane fuel.

With a low-level tuner you can change the high and low injector slope scalars to fix this. Some "handhelds" (and the Sniper SF) allow WOT fueling corrections and can do a lot to correct the WOT AFR, but in a less precise manner.

yeah that's really rich.

I had a bunch of people on here tell me that right around 12 was good on a naturally aspirated car. With my tuner saying 0% richer or leaner im at 12.8's but right now I have it at 2% leaner which puts me in around 12.2s at wot. So is that good. Ive noticed the exhaust isnt so strong or rich smelling with the 2% lean tune on. I know some of this info was from cliffyk and they all said that being on the rich side was better for more advanced timing. Just wanting to make sure my tune is right and im reading my air fuel gauge right thnx.