[Tommy]

I saw the point made by CSXDreamer illustrated on one of those half hour car shows where they hop up cars. They took a showroom stock import sedan and prepped it for road racing. They started by taking dead stock dyno readings and lap times. Next they upgraded the wheels, tires and brakes, and did some intake and exhaust improvements before putting it back on the dyno. They were surprised and befuddled when the modified HP at the wheels was lower than the baseline. They later figured out that the upgraded wheels, tires and brakes had more angular inertia than the stock equipment. Ultimately, all the improvements they did to the engine served only to restore the HP at the wheels to what it had been when the car was stock.