Like the title states, my car wont rev past 6300-6400, it's like it's hitting a rev limiter. Even if I ease into it to that rpm, it still wont go past it. I noticed that in my datalogs, when I map out rpm and vbat, there is a correlation.
when my rpm's peak, my vbat goes down and the peak of the rpm and trough of vbat coincide. Tonight, at 6409 rpms, my vbat was down to 12.06. when cruising, vbat stays around 13.3.
I have had my alternator and battery tested. The battery was fine, but low on charge, 12.3V iirc. The alternator tested out fine as well. I have datalogs of the car going up to 7200, so I know it used to rev up that high.
Could anyone offer up where to start looking for issues? The car doesn't stumble or do any kind of other missing anywhere else in the rpm band. I'm still thinking alternator issue.
331/T5 - Probe Flat-tops, Vic Jr heads, Comp Cams 280HR, 1.73 rockers, Vic Jr intake, Massfloefi TB, GM 87mm MAF, 36lb injectors, 4.11 gears
346rwhp with carb
'12 Mustang GT
5.0/6 speed, 3.73 gears, HID's, coil-overs (it's LOW)