Does This Seem Right? (Tire Question)

Hi Guys,

I just added a pair of 315/35 17 Goodyear F1 GS-D3's out back and now I cant chirp the tires. Are these things really that much better than the old 245/45 17 Kumhos I had out there? The car seems accelerate a lot smoother with these tires, but I miss being able to chirp. Do I need to just try harder (whatever that means) Or are these tires just to big for a basically stock motored mustang to overcome?

Thanks,
 
You should still be able to chirp tires. Sometimes when you get new tires the traction is really good initially and as they wear a little the traction will be easier to break. Give them a week or so and see if they don't break easier.