I recently bought a '06 Z w/ about 5k miles on it. Its seems to me that when I rev out the gears (MT) the engine revs seem to stay up and don't drop as fast as other cars I've owned. Only mod done has been a Stillen true dual exhaust.

Is this normal and if not what might be causing that?

Thanks,

Mojo

 

Does it cause the car to jerk when up-shifting?

 

Different car.
Different motor
Different flywheel.

 

It's normal in the Z.

 

get a lightweight flywheel, your revs will drop faster just like it will rev faster.