I'm looking for a good set of drag radials for my 2012. I've been running the NITTO NT555 for about 9 months now. I'm looking for something w a little bit more grip, something more aggressive. Does anybody know or recommend a good set of drag radials to try out, and what's the best size to get???

I have the stock brembo 19" wheels btw

 

I've had good success with Mickey Thompson on 17" wheels. I'm sure others will provide sizing for you year as I have a Mach and can't provide proper feedback for you car.

 

how do they handle when driving in rain?

 

Don't!
I run the Nitto DR's. Just don't drive them in the rain ever! Dry conditions they are fantastic. Even on curves they are great.

 

MT ET Streets are the best radials you can get for grip on dry pavement. But they are the worst in rain. I've driven both Nitto's and MT ET Streets in the rain. Nitto's handle just fine. The ET Streets on the other hand are scary in the rain.

 

You need a dedicated set of drag tires, none of the available drag tires will be very good for a daily driver, they where out fast and are hazardous in the wet and cold.

I take it your car is a manual?

Best hook for a drag radial on a manual is going to be on a 15" wheel, and either a 275/60-15, 28" tall, or with 3.31 gears, use a 275/50-15, 26" tall.

Going with a 15" wheel gives you a taller sidewall to help absorb the shock load from the clutch engagement on launch.