Wierd Problem with new tires.

Its because the car calls for at least a "V" of "Z" speed rated tire.yours are "H",,its more of a performance all season tire(Bigger sidewalls) I did the same thing..But the H's are "much" better in the weather!!

All the speed rating tells you is how fast the tire can go under maximum load. There are some pretty good all season V rated tires that are better than some H rated tires....It just doesn't make that much of a difference.

definitly drop the air down to 30-32psi.at 38 psi only the middle if the tire is contacting the pavement.it'll just prematurly wear the centers of your tires out like that.too little air will wear the inside and outside edges out.

did you have the car aligned at a shop, changing the springs and not having a proper alignment causes your problem. if it was done ,does it feel right to you as in going straight or is it drifting to one side.
is the steering wheel off center ?

If you put in B springs and the front tires are wearing on the insides, you may need caster/camber plates. You definitely need an alignment in any case. 400 treadwear tires are not sticky at all. You basically have installed a non-performance tire that has lots of sidewall flex and a hard compound. To make matters worse, your alignment is off. I can only imagine how crappy it must feel to drive your car. Sell the tires and get an alignment and some performance tires. Be prepared to fork out dough for CC plates and another alignment if the shop can't set up your car with the factory plates. Good luck.