I've run 12.91 @ 105 mph on 87 octane, i get no detonation, but with my old stock e7's i HAD to run 93 with advanced ignition, even in the cold weather.
on 93 i have the same results you do, i tried some VP 104 one day, and it made my car sputter, and slow down.
Good thread here. 
__________________
X-Texas highway patrol ssp 1990 coupe - exploder Gt-40 iron heads, Explorer intake, 19 lber's. E-cam. crane 1.7 rollers. 190fp. 75mm maf. 65mm tb, tubular subframe connectors, mac cai, Asp crank pulley, T-5, king cobra clutch, flowtech 1-5/8 unequals, mac X-pipe Frpp driveshaft, lakewood Lca's.
race weight 3,160
12.69 @ 107.35, 1.71 60' 26x8.5 drag's 3.90 gear
13.20 @ 106.91 - 235/60/15 firestones 2.3 60' 3.27 gear
|