The p zeros on the redeye are the summer p zeros.I only bring up the tire, because of all the past complaints about the ZL1 1LE having superior tires on Road Course downplaying how good it is, or the complaints about the demon drag radial/skinny stuff.
4-5 seconds is a longtime on that course but anyone who thinks the redeye would not cut close to that much time going from a Pzero all season to the cup 2s is crazy. But if you were to admit that you would admit that the Redeye on equivalent tire would we very close to the GT500 on the course, much like you say the gt500 on a equivalent tire would be very close to the Demon. hmmm...
Also, the Redeye would pick up at least 1.5 seconds with a cup 2, probably more.
P zeros are a stupid tire, they have decent grip in a very narrow window. If they are cold they have less traction than they should, and once they are past their optimal window they get surprisingly slick again. If you can keep them in their window they aren't far off of a MPSS.