1.slicks- you want more surface area on the ground and tires it will decrease tire slipping.(you do not want to drive in the rain with these)2.limited slip differential- this also limits any tire slipping 3.cold air intake- cold air will make the mixture more explosive and will push the pistons down 4.exhaust system- an exhaust system will reduce back-pressure that will increase engine response, more mpg, decease the the load on the engine. (remember it will create a loud sound, when people like the sound they get on the engine to make it louder)5.manual transmission- there is less slippage in the transmission6.turbo- turning off the boost can increase efficiency7.super charger- at moderate speed and low boost the efficiency can be over 90%.8. spark plugs- they will create a better explosion9.spark plug wires- they will create a better explosion by getting more electricity to the spark plugs 10.gas pump- pump more gas to the engine11. strip the interior- reduces weight12. limit electric use- less load on the alternator13. aerodynamics- slide though the airhope this helps/ gives you an ideacheck out this website: http://www.andysautosport.com/