i also tend to track my car alot, every tuesday out at irp, and i'm wanting to start autox it this summer.
i'm putting falken Falken Ziex ZE-512 on the back, and falken Falken Azenis RT-615 on the front.
Good Lord! [eek]
Is it too late to change your order?
That combo might work for the 1/4 mile, but it will be:
1) Horrible on the street, especially if you ever have to drive in the rain.
The 615s once worn down will not work well in the rain, and even when new will have much less grip than the rears.
You're going to be plowing into everything...curbs...trees...
2) That combo will be equally as bad on an AutoCross course.
The tremendously improved
dry grip of the 615s over your rear choice will have you spinning out all over the place.
Exactly why do you want to use 2 completely different tires??
And...those 2 really couldn't be that much farther apart...