Check Out That Chassis
In most cases when the car goes to the left you have to much load on the right rear tire. I would take 1 flat of preload out of the top right bar and try it again (you will be lengthening the bar). Video the runs; this will help you figure out if it is the preload that is sending the car left. The next thing that is going to get you in Big trouble is 0 tow in? You need at least 1/8" of tow in just to make sure you have any under load at speed.
President, S & W Race Cars