brightbluesaleen

My newly rebuilt 4.6, .20 bored over, comp 270 cams. Having an issue tunning it. Half throttle, 3/4 throttle everything runs perfect. A/F ratio is at 12.5 and the car accelerates good... the second I put my foot right to the floor the car bogs and reads all the way up to 9.5 10.0 on the A/f ratio.. draw through set up with a used 90mm maf and the stock bypass valve from vortech.... any help would be fantastic