New brakes, not much better

I just had new stock diameter drilled and slotted rotors and NAPA ceramix pads installed on my '97 GTP, but it didn't seem to make alot of difference compared to my old stock brakes. My girlfriend has stock brakes and pads on her '97 GTP and it seems to stop much better than mine. Her's really grab when you mash on the brakes. Any ideas why mine aren't as effective? Thanks!

IMO the ceramic pads.

IMO, it's both the pads and the rotors. Drilled and slotted rotors give less overall surface for the brake pads to grip. Their only advantage is in EXTREME braking like rally-cross racing or canyon carving in the mountains. In these situations, the rotors dissipate heat better and reduce fade. Otherwise, they actually reduce cold braking efficiency. That's why the OEM's don't use the carbon fiber brakes that Formula-1 cars have, they're not worth a crap when cold. Ceramic pads, while quieter and cleaner (no black dusting), have a slightly less maximum coeffcient of friction than a quality semi-metallic pad, so they don't stop quite as well in panic type hard braking.

The carbon pads have been homogenized or domesticated and work quite well now for non-racing applications. You can get the Performance Friction Carbon-Metallic pads which work pretty darn good even compared to the OEM. I use Performance Friction brand pads with Raybestos PG rotors. By compounding, the metallic improves braking. The carbon element provides stability at elevated temperatures whereby making the pads less likely to deform and deteriorate. Plus the cost is reasonable at $50 per set.

BTW - Although brake dust is still there it is minimal and these pads are quiet!!!

I have to agree with both Rich and Bob! Heat the ceramics up and see who stops faster the performance friction carbon metallic pads are an excellent choice and I highly recommend them. I have had great success with them in the past.