I went an easy 9.79 off the trailer in 2012 and have been 6.15 at 112+ in the 1/8 with a crappy 1.40 60 ft. a couple years ago BUT my adapter was fully ported and blended into the plenum which I know helped. A heavier car needs a bit more velocity to get it going and enuff volume to pull through the traps so a dedicated 4500 manifold MAY be faster, may not be but I can build ya a high velocity/volume 4150 up to 1100+ cfm if needed.....