Back in the '60s, the really cool hot rods were the mid-sized sedans with the mountain motors. Cars like the Chevy Chevelle, Olds Cutlass, Ford Torino and Pontiac LeMans were not widely regarded as sports cars, but when stuffed full of a zillion cubic inches of iron and given cool tags like GTO, SS and 442, they became serious performance machinery.

The same is true today with the BMW 3-Series. While the standard 318 and 325 are good cars to begin with, once the M3 tag is hung on the trunk lid, it's a whole new car. The factory hot rod M3 is even attracting a following among modern gearheads, so while the '60s rods were tweaked by companies with names like Holley, Crower and Edelbrock, it's companies like Autothority that are pushing the performance envelope with today's sophisticated machines. This high-tech tuning firm is best known for their performance chips, but Autothority produces a host of other modern go-fasters.

The Autothority M3 is the company's showpiece for what their brand of hot rodding can produce. The difference that is instantly obvious between the '90s rocket sled and its distant cousins is the level of civility achieved by the new car. The Autothority M3 is a daily driver - a feat that could never be accomplished with a Hemi 'Cuda.

So how does this company take an already phenomenal car and make it is even better? The answer is a delicate blend of subtle changes that maximize the M3's performance potential.

Autothority starts by substituting the M3's stock E-PROM with a custom programmed chip. While the subject of hi-po chips could make a complete story in itself, we'll just say that the Autothority chip is programmed to provide a different ignition advance and fuel mixture, yielding better performance when used with high-octane fuel. The company claims an approximate 8 percent increase across the rev range in both power and torque. The chip sets a 7000 rpm rev limit in all gears and also disables the M3's top speed limiter, allowing the car to achieve its true top speed.

Autothority didn't rely solely on ones and zeros to make performance, however. They also added some trick reground cams and a lightened flywheel to make things happen quicker. An Autothority Flowtech cold air induction system allows more air to enter the engine, providing improved airflow for increased mid- and high-rpm power. The result of this massaging is a dyno-verified rating of 295 hp at 6800 rpm and 268 ft.-lbs of torque at 4500 rpm.