racecar

Is it possible to get a good tune by reading the O2's, without a wideband??
I have a 25 minute road race in 2 weeks and I need a tune for my 99 C5 6 speed, headers, no cats, smooth bellows, dual K&N, no screens MAF.
I used LS1edit to eliminate the rear 02 sensors and Air pump. Have not changed the fuel curve yet.
I logged data for the first time last night, Wow, this stuff is really cool, WOT on a country road with the laptop plugged in.

I can see that it switched to open loop at WOT. It is running rich as I expected, 1060, 1065 on the 02s.
From reading this site I understand that I need to change the PE table to lean out the open loop settings. Is it accurate to do this with feedback from the 02 sensors. I am reading that most everyone has a wideband for power WOT tuning. Is this a requirement, or just a luxury???
Is there a good chart for 02 = a/f ratio? 880 is good??
Thanks

slow

iTrader: (7)

narrow band stock sensors are not arrurate enough to get a good tune with them.

while people may use them, its not the correct way to do it. 880 is generally accepted to be lean.

Ryan

racecar

I have read on other threads that 860 on the 02 is lean, 870-880 makes a lot of HP, but it is still close to lean. Probably closer to 880 or 900 would be safer, since I am WOT over 50% of the time for 25 minutes in road racing. I may try a few adjustments this weekend and check it out. Looks like I need to get that wideband on order and installed soon. What is the right number with a wideband, is it 12.7 for max power??
99 Corvette Road Racer