I am getting coil overs soon to replace my tired shocks and soft springs. My plan is too use 17" wheels with stickier 275/40/17 rear tires for tracks I am familiar with and the stock wheels with more street 245/45/16 tires all around for tracks I'm less familiar with.

My question is, will the varied height going from each set up require adjustment? Would it not effect the corner weight?

According to this tire calculator:
http://www.miata.net/garage/tirecalc.html
The 275/40/17's are 4% taller than the 16's. Calculator says an inch taller.

 

I'm really failing to understand your reasoning for running two different setups...especially since running a wider rear would be more forgiving than the stock setup.

In any case, if you set the car for flat with the 16s, the rear would be about 3/8" higher with the 275 17s. That's assuming your front tire diameter remained the same in either setup. You could run a 235/45 17 up front with the 275/40 rear and be only .1" higher or so.

 

Thanks for the reply.

Every classroom and in car intstructor I've had suggests running slower tires on tracks one is starting to learn. They are more forgiving by breaking away less abruptly at the limit. Street tires are like training wheels I guess. They also make you focus on the line and being smooth. While the stickier beefier rears would mask driver error as long as I was not at the limit, I want to learn more about the cars handling on that edge.