The more I look at your timeslips, the more I'm convinced the car is running about what it should with a fairly stock suspension and street tire. There may not be much more in it.
IDK about that. At 112 MPH he should be at least a 12 flat, even with his chassis and tires. That's probably 360-375 HP. I'm guessing on a 3300 pound car weight.
My car has been 12.42 at 109something...almost 110 and it was motoring from about 1000 feet on. And that was on 4 crap shocks, two of which were actually broke.
Edit: that was also on some home made slapped bars and a DOT tire.