More wheelspeed plain and simple..If it launches and drives straight after the launch then it clearly is not a brake, chassis or tire thing. Since you say its a burnout thing I assume only when which means you need more wheelspeed. HIgh gear and how much depends on the car but enough for it to go straight is the answer

"I am not ashamed to confess I am ignorant of what I do not know."

"It's never wrong to do the right thing"