Join Date: Nov 1999
Location: Midland, TX, USA
Target Air Fuel ratio for NA Cobra 4v?
Just used a Bailey AFM-1 on my 99 Cobra. It is lean at 14.0:1 Air fuel ratio at wide open throttle in 2nd and 3rd gears throughout most of the rpm range. Richest I saw was 13.9 at 6200 about. My understanding is that the target should be 12.7-13.0 normally aspirated. What do the tuners normally shoot for on normally aspirated street engines when burning chips?
I don't have a data logger set up yet to take the output from the wide band and an rpm signal and record it real time on a lap top. But I'm working on it.
99 Cobra Convert, 99GT live axle, 31 spline C-Locker, Mark Williams axles, HPM upper and lower, FMS alum driveshaft. Pro-Motion pro-shifted TKO-500 trans.
28x10/15 ET Drags on Pro-Star 15x10, 6.5BS wheels Star Stage 3S clutch, MAFterburner Plus, Aeromotive A1000-6 regulator, return style fuel system,
Aug, 2003 forged motor, HP cams, SHM valve springs, short runner intake, SCT Flasher for tuning. Best
150 shot is 10.77 at 127.8 mph in very good air. 1.35 60'.