horsepower rating help...

[wildbird]

ive noticed that the l98's are rated by their brake horsepower..... while the the lt1's are rated through flywheel horsepower.... i know that my 88 gta has 225 brake horsepower.... but how much horsepower does it have at the flywheel and horsepower at the wheels..... and there is one more question.... why is it that all those 60's and 70's cars have those outrageous 400+ horsepower ratings..... could a gta outrun any of those old "muscle" cars... ive never understood why they have so many ways of rating horsepower..... is my 88 gta more powerful than those "muscle" engines..... someone please help me out....

[FrankieRider2]

The great musclecar engines of old had their horsepower rated outside the car with no accessories installed (gross), whereas cars since 1972 or 1973 have had the engine power rated after installation into the car with all accessories hooked up (net).

To illustrate, some of the old Ram Air engines from Pontiac in the late '60s offered in the GTO and other models had as much as 370 hp gross.... while the '73 Trans Am with the Super Duty 455 started out with 310 hp NET at the release of the engine. Those cars clicked off 1/4 mile times of 13.54 in stock trim.... incredible for that heavy of a car in those days.

[wildbird]

oh i understand thanks.... would you happen to the gross horsepower of our gta's.... and those sd 455 engine were powerful.... those 2nd gen cars are much heavier than ours.....