Stock HP Underrated?

[87Turbo-TWE4]

I've always heard that the stock numbers were underrated but by how much?

 

[ross87t]

245hp usually doesn't power a 3400lbs car down the track in 13.9-14.2 seconds.
I'd say they underated them.

 

[jasjamz]

Maybe they meant rear wheel horsepower LOL!

 

[pacecarta]

gns dont weight 3400,
race weight is driver and fuel and spare as it was from factory with the gn rims
typical weight of a GN is 3800+ with driver
though lighter wheels and remove spare and lighter driver (under 200) less fuel and you can have a race weight of a gn in the low 3600s
do alum bumper and lightweight rims , f body rad and 3500s isnt too hard
do some fiberglass parts like bumpers and hood and ditch the a/c and you might get down to a 3400 race weight

factory 245 hp ratings were pretty accurate even with gm policy on not advertising more hp than the vette but making more was easy with a chip better fuel and turn the boost up a little
but , 14.3 ET is accepted as the as shipped performance hen new and with driver race weight of 3800#, punch those numbers in any online calcuators and 255 is about is what youll get

 

[Chuck Leeper]

Dyno pulls @ Ruggles with stock, out of the crate 87 engines + 290FWHP. [Was there when it was done.] He had 2 dyno's. 1 for the ladies best friend.. the vibrator V-sicks, and 1 for the V-8s...

 

[ross87t]

gns dont weight 3400,
race weight is driver and fuel and spare as it was from factory with the gn rims
typical weight of a GN is 3800+ with driver

I wasn't really refering to "race weight", but I assume I might have been about 100 lbs under your typical power window/locks 1987 GN.

Edmunds - 1987 Grand National

Curb weight, as tested (lbs.) 3,509