I agree with BigDan. Use the oem damper, your crankshaft will thank you. In fact, a bit more rotational weight is an advantage you will notice in normal driving. More tractable at low speeds and takeoffs. The low rotating mass of a 4 cyl engine and low torque makes this more evident. I resisted the urge to go with a light flywheel for the same reason since I will use my car more for a gt than a track car.