ok what i want to know is hpw much rwhp do i need to beat a 2003 cobra with the 390 hp? what about the older cobra's? i have the typical 4 door v8 right now but this would be after i built the engine of course. i know there is a calculation for the weight of my vehicle to horsepower ratio to get it to such and such 1/4 mile time. and then all i need is the 1/4 mile time by the cobra. any help would be much appreciated. thanks.