Ladder Bar preload
 

If I have to much preload in my right ladder bar, will it drive my car to the left?

yep.

Yep, again. But, to expand on that, the car can also veer to the left when you don't have enough preload.

Yeah, that's confusing, but, if you have little or no right rear preload, the left front can pop up in the air on launch, causing transient loading of the right rear and a veering to the left. Some racers will even preload the left rear to eliminate this effect. The result is that they have a car which does, indeed, launch straight, but they're paying for it in decreased performance as that transient loading disappears and the driveshaft torque unloads the right rear.

The best answer, of course, is to have a car which retains equal rear tire loading both before and during the launch. My site has some suggestions on how this can be achieved.
http://www.racetec.cc/shope

I was kind of in a hurry to get it done and had no testing before the last race. I might have put an extra flat into it. I am using the CE ladder link bars. I doesn't pull hard to the left, just kind of drives that way. Not hard to straighten out. Thanks for the replies.