ok so me and my friend set up a street race on a long straight strip at an industrial park. he drives a 2002 civic ex with cold air intake and cat back exhaust and i drive a 97 civic hx (completely stock). mine is 115 hp stock and his is 127 stock but with those mods it would be more. he pulled off the line a little quicker than me but i kept up and was only about half a car length behind the whole time. oh yeah and we both drive manual. so shouldnt i have lost by more?

not if you are a better driver than him.

Its all about power to weight ratio - which the HX wins

does weight really matter that much? i looked up the stats on a website and i think theres only about 150 lbs difference maybe. and i think we're about the same ability as drivers. any other ideas?

Yes weight matters, just not a whole lot when comparing 2 slow cars . . .

1HP = the ability to move 33,000lbs - 1 foot in 1 minute or 550lbs 1 foot in 1 second. That is how horsepower is measured.