the torque converter can be replaced with a high stall.
remodel the i/c to a top mounted version ala sls and you will get huge gains.
meth install
lsd for better traction
the exhaust from needswings is a proven winner. add mid length headers for more low end torque
tunes.... theres always new developments in this area so maybe send yours back to inmotion for a new upgrade
weight reduction... this is a great way to find speed without gutting the car. lightweight rims tires and seats to start. shuriken battery spares jacks and unneccesary tools out. lightweight rotors help. im thinking every 100 lbs removed =1/10.

all of this will get you into the mid 11's, however it comes at a steep price. that in itself is why most modders will jump on the nitrous or turbo train. its cheaper and priduces the same results.
if you want a 10 sec xfire you are gonna need 2 more cylinders. unfortunatly this is a sickness the need for speed!! what ever you end up with its never enough and the search forever continues for another 1/10th of a second!