G-TECH usualy is about 4-5mph off from the track because it measures the whole 1/4 mile where as the track does not just as xgmguy said, my car may pull 112+mph with the G-TECH but only 107+mph at the track but the ET is fairly close.
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98'Trans Am LS1 A4 273 gears Whisper lid,K&N,Flowmaster,Best ET on street tires 13.17 @ 106.49mph
NEW MODS:3" Flowtech cutout,Magnecor wires,NGK TR55's