what should my air fuel be??

[jasonsnova]

so i just bought a wide band o2 sensor for my nova , what should i be looking for for a/f ratios at idle,part throttle, and wide open throttel???
keep in mind its a sbc and see's 4-5 times a year at the drags, when it goes to the strip it see's 150-180 shot of nitrous... thanksssssssss

[jasonsnova]

no one?
so ive been looking into this a bit more and seems the 14.7/1 ratio most oem cars use is best for emmissions not performance, and is actually a bit on the lean side,even more so at wide open throttle, so im guessing some where around 13.5/1 @ part and WOT ????
i'd really like to hear from a dyno guy or some one who has tuned accordingly......???

[tumper93]

Go here, there is more information here than anywhere and they can answer your question if you cannot find it
http://www.innovatemotorsports.com/forums/index.php

[68Formula]

14.7 is usually for cruise or idle and mostly for emissions (HC, NOx engine out, and proper catalyst function). At cruise and idle even leaner is possible with the correct ignition timing which would improve fuel economy. Experiment with ratios as high as 17:1 and as you increase the ratio, also try higher amounts of timing (higher than typical stock vehicleS) in conjuntion with each step. You are looking for the highest vacuum reading with the leanest a/f (If you had a way to monitor for lowest CO levels that would be the best, but requires expensive emission dyno equipment). If you get a shuttering at constant speed as you lean it out and it does not improve with increasing the timing at that point then you have reached your limit for that cruise rpm.

Then map in your WOT a/f timing.

Get all that done, then you are ready to adjust tip-in and part throttle conditions looking for best throttle response.

If you have to run richer at cruise to get good throttle response then typcially you don't have sufficient timing, or you don't have sufficient tip-in fuel.

At $4/gallon take advantage of the adjustability that EFI offers.

[jasonsnova]

lol....map in?? haha.....i have a holley hp 750, i just want t be able to lean it out a bit with out worrying about blowing it up on a nitrous run!

[68Formula]

Brain fart, thought I was still in the EFI section.