Won't this be very hard to control with it wanting to dart one way then the other? At the speeds you are going to be at it just sounds scary. Maybe I am wrong & it takes more tow-out to do that?
John
How much toe-out before the car starts to feel unstable is a very good question.
The problem is, as the suspension rises or dives, the toe-in changes. As the car rises you get more positive toe-in which causes tire scrubbing, but maintains good steering control. As the car dives, you get more negative toe-in (toe-out). Toe-out also causes tire scrubbing, but worse steering control.
The dilemma for the racer is that the car runs at a higher front end ride height accelerating down the track. As the car rises, the tires toe-in more and drag is created slowing the car down. Steering staying stable though. At the end of the run, and during braking the front end dives. At a certain amount of dive, the toe-in will go negative. Negative is never preferred, but with our style of suspension, it can't be avoided. The more positive toe-in that is adjusted in, the more dive it takes before the toe-in will go negative. But the more positive toe-in you adjust in to prevent from going negative on a dive, the more positive the toe-in will go at that certain amount of front end rise that your car runs down the track at.
The toe-in adjustment is a compromise between the amount of drag due to tire scrubbing during acceleration, and the amount of negative toe-in that you will end up with during braking and front end dive. When you pick to adjust toe-in for the least amount of drag for the run at a certain amount of front end rise, it means you will have more negative toe-in during braking.
One way to prevent the toe-in from going negative is to restrict or limit the amount of dive travel that the front suspension has. That way you can get away with adjusting the toe-in to zero at a higher front end rise figure.
It could very well be that a small amount of negative toe-in can be tolerated. I don't know. Maybe someone with experience can let us know.