lightweight flywheel and sport clutch. most bang for the buck if you want instant performance that you can really feel. i'm going to get mine sometime later today or tomorrow. i should have gotten it this morning, but my ride fell through. 1/2 sec off your 1/4 mile time. tire spinning fun if you mash the gas with no regard for your tires. incredible gains in 1st, 2nd, and 3rd. and if you're going to do the flywheel, get the clutch done while you're at it. all together, mine came in a tad over $1900 for parts and labor. and if you drive normal, the sport clutch will outlast the stock one by easily 2x the mileage and abuse.